Eutrophication caused by nitrogen, phosphorus and organic pollutants is a common problem which has attracted much attention in China. Ammonia nitrogen, as a main pollutant, should be removed efficiently to avoid the extension of eutrophication. In this research, Prussian Blue (PB), which can not only capture ammonia nitrogen by vacancy in crystal cell but also degrade organic pollutants by Fenton oxidation, was combined with modified biochar to increase efficiency of ammonia nitrogen removal. Several characterization methods were used to investigate the structure and morphologies of the biochar composite. Adsorption capacity of biochar composite material (BC700-PB) was tested by NH4Cl solution. The results show that the maximum adsorption capacity to ammonia nitrogen is 24.4 mg/g and the removal efficiency is over 95% within 60 min under the condition of pH 8, which is 101.3% higher than that of the unmodified biochar. The adsorption mechanism of BC700-PB was investigated with Langmuir model and pseudo-second-order kinetic equation which reveal that the adsorption including physical adsorption by biochar and coordination adsorption by PB. Meanwhile, Fenton oxidation process is conducted by PB nanoparticles in the biochar composite material with existence of H2O2. The biochar composite material could catalyze H2O2 to generate ?OH, and achieve degradation of organic pollutants and adsorption of ammonia nitrogen. The PB/biochar composite material can be recycled easily by NaCl solution for several times. In conclusion, the PB/biochar composite is a promising material for eliminating multi-component eutrophication wastewater.

Conventional trifluoroacetic acid metal organic chemical solution deposition (TFA-MOD) method for the preparation of YBa2Cu3O7-δ (YBCO) superconducting layers follows the BaF2 growth mechanism. In this work, a novel chemical solution method based on BaCl2/BaF2 pathway for the growth of YBCO superconducting thin films was carried out. The effects of Cl addition on grain orientation, microstructure and superconductivity of YBCO thin films were investigated, and mechanism of the phase transition of YBCO thin films in the BaCl2 pathway was explored by thermochemical calculations of the growth reaction. The results show that the Cl addition inhibits a-axis grain orientation and promotes nucleation of c-axis grains. Onset transition temperature (Tc-onset) of the YBCO 2-layer film is about 89.6 K without significant change after Cl addition. But its critical current density (Jc) is significantly increased to 2.07 MA/cm2 (77 K, self-field). Meanwhile, the phase transition of the growth reaction process shows that Cl is preferentially combined with Ba to form BaCl2 as much as possible, effectively avoiding the formation of BaCO3. All results of this study indicate that Cl addition facilitates preparation of YBCO superconducting thick films, and provides a new idea for the preparation of YBCO by MOD method.

Transparent AlON possesses good mechanical and optical properties, which shows great potential for application. However, high fabrication cost seriously restricts its wide usage. To solve this problem, gel-casting and pressureless sintering of transparent AlON was tentatively studied here, with emphasis on low temperature synthesis and anti-hydrolysis treatment of AlON powder. It was found that fine AlON powder could be readily synthesized at a low temperature of 1700 ℃ by a novel carbothermal nitridation technique, using polymer coated AlN/Al2O3 mixture as the starting materials. The powder obtained was submicron in size and its hydrolysis resistance could be significantly improved after surface coating with a polyurethane layer. On the basis of these findings, transparent AlON ceramics was successfully prepared through gel-casting and pressureless sintering. The material sintered at 1850 ℃ showed good optical and mechanical properties, with a high in-line transmittance of 83.1%-86.2% from ultraviolet to mid-infrared and three-point bending strength of 310 MPa.

Polymer derived ceramic is one of the effective methods for producing ultra-high temperature ceramics and powders, but effect of source material type on precursor cross-linking degree and ceramic yield has rarely been reported. Here, TaC precursors were synthesized using two carbon sources and poly-tantalumoxane (PTO). Phase composition and microstructure of TaC ceramic powders from different carbon sources, tantalum/carbon mass ratios, and pyrolysis temperatures were characterized. It was found that PF-3 resin with C=C was effective in promoting the cross-linking of PTO and increasing the ceramic yield. When the mass ratio of PTO to PF-3 Resin was 1 : 0.25 and PTO to 2402 Resin was 1 : 0.4, TaC ceramic powders could be obtained at 1400 ℃ without residue Ta2O5. Ceramic yields of ceramic powders were 54.02% and 49.64%, and the crystal sizes were 47.2 and 60.9 nm, respectively. Therefore, PF-3 resin is able to reduce crystal size while increasing ceramic yield, but has less impact on the powder purity and particle size. The purity of TaC ceramic powders derived from different carbon sources are 96.50% and 97.36%, respectively, meanwhile the median diameters are 131 and 129 nm, respectively.

Continuous silicon carbide fiber reinforced silicon carbide composite (SiCf/SiC) is a key material for the advanced aero-engines. It is required to possess excellent high-temperature creep resistance for SiCf/SiC to meet the long-term service lifetime of the aero-engines. Here, tensile creep behaviors of a plain woven Cansas-II SiCf/SiC (2D-SiCf/SiC) were investiged in the temperature of 1200-1400 ℃ with the stress levels of 80 to 140 MPa. Its microstructure and fracture morphology were observed, and composition was analyzed. Results show that creep-rupture time of 2D-SiCf/SiC is more than 500 h and steady-state creep rate is 1×10-10-5×10-10 /s at stresses lower than the proportional limit stress (σPLS). The creep behaviors are controlled by matrix and fibers. The creep-rupture time is significantly reduced, and the steady-state creep rate is increased by an order of magnitude when the stress is higher than the σPLS. The matrix, fibers and interfaces of the composite are greatly oxidized, and the creep behaviors are mainly controlled by the fibers.

In recent years, phase separation glass has attracted extensive attention because of its unique structure and excellent properties. But its mechanism of phase separation on glass remains insufficient clear, especially, the influence of recombination time on structure and properties is unclear. Here, strengthened P2O5-Al2O3 glass with SiO2-Na2O high-silicate glass particles as the second phase was prepared by melting-quenching method combined with pneumatic atomization and mechanical stirring. The relationship between structure and mechanical properties of the glass was investigated by varying the recombination time. Experiment results showed that Young's modulus of the heterogeneous composite glass was higher than that of the P2O5-Al2O3 glass. Young's modulus of the sample firstly increased and then decreased with the recombination time increasing from 10 s to 8 min. The highest Young's modulus of 80.7 GPa was obtained at recombination time of 6 min, which was increased by 18% as compared with the P2O5-Al2O3 glass. Introducing SiO2-Na2O high-silicate glass particles not only formed the second phase in the matrix glass, but also changed the structure of the P2O5-Al2O3 glass. As the recombination time increases from 10 s to 6 min, coordination number of phosphorus in heterogeneous composite glass network gradually increases, while amount of non-bridging oxygen in the glass network gradually decreases, resulting in a gradual increase in network cross-linking. However, when the recombination time is more than 8 min, it is not conducive to network crosslinking. Therefore, development of heterogeneous composite glass can provide a new route for the preparation of glass materials with good damage resistance.

The smaller the size of the Bi2Te3-based micro thermoelectric device, the more significant the effect of interface bonding strength and contact resistance on the mechanical properties, open circuit voltage and output power of the device. It is of great significance to develop a thermoelectric unit preparation technology with low cost and simple process, and to enable the interface between n-type Bi2Te3 bulk materials and barrier layer with low contact resistance and high bonding strength. Here, surface of n-type Bi2Te3-based thermoelectric material was treated in mixed acid solution (pH~3), followed by electroless plating Ni (5 μm), and then welded with Cu electrode to prepare thermoelectric unit. After corrosion, the anchoring effect between large gully on the surface of n-type Bi2Te3-based thermoelectric materials and Ni barrier layer contributes to the interface bonding strength of 15.88 MPa for the material corroded for 6 min. Furthermore, nano-holes between the Ni barrier layer and the fine branches corroded by further corrosion significantly increase the interface contact resistance, resulting in 2.23 μΩ?cm2 for the material corroded for 2 min. Finally, the output power of the micro thermoelectric device prepared by n-type Bi2Te3-based bulk material for 4 min corrosion treatment is as high as 3.43 mW at 20 K temperature difference (306 K at high temperature end and 286 K at low temperature end). Compared to device with the same size prepared by commercial electroplating coating, the output power is increased by 31.92%. This work provides support to optimize the performance of micro thermoelectric devices.

Compared with other electric energy storage devices, dielectric capacitors made of dielectric composites have great advantages in fast charging and discharging capacity with high power density. A dilemma of improving the energy density of dielectric composites and synchronous optimizing their breakdown performance is becoming an intriguing research direction. To further adjust the contradiction between dielectric constant and dielectric breakdown performance, here a finite element numerical simulation based on dielectric breakdown model (DBM) was proposed to study the effect of the distribution of inorganic fillers on the electric field and breakdown damage morphology in flexible polydimethylsiloxane(PDMS) based dielectric composite system. The results show that a large dielectric difference is observed between filler and matrix, which indicates that polymer matrix with a large dielectric constant or inorganic filler with a small dielectric constant can realize reducing the size of the high electric field area at the interface and improving the breakdown resistance of the material. This study further reveals that the more dispersed structure of inorganic fillers, the more likely its dendritic damage channels tend to branch, indicating that this situation is conducive to the increase of damage sites of dielectric breakdown dendritic damage channels, the decrease of damage rate, and the improvement of breakdown resistance of materials. All above data demonstrate that this study provides certain guidance for the development of organic-inorganic dielectric composites with both high energy storage and excellent breakdown performance.

As a colossal magnetoresistance material, the perovskite manganese oxide La1–xSrxMnO3 (LSMO) has broad application prospects in magnetic sensors and other fields. However, it is difficult to obtain a significant colossal magnetoresistance effect at a low magnetic field at room temperature. To improve its magnetoresistance effect and transition temperature, La0.8Sr0.2Mn1–xAlxO3 (0≤x≤0.25) (LSMAO) polycrystalline samples were prepared by traditional solid-state reaction method in present work. Effects of Al3+ doping on the electrical transport property and magnetoresistance of LSMO were systematically analyzed. The X-ray diffraction (XRD) results indicate that all samples crystallize in a single rhombohedral structure with the space group of $\text{R}\bar{3}\text{C}$. Result of electrical transport property shows that resistivity of the samples increases exponentially with the increment of Al3+ doping amount, and the metal-insulator transition temperature is increased by an external magnetic field. This phenomenon may be attributed to dilution of the Mn3+/Mn4+ ions network by Al3+, which increases the magnetic disorder but reduces the number of carriers. In addition, the conduction mechanism of LSMAO ceramics change from the small polaron hopping model (SPH) to the variable range hopping model (VRH) after doping of Al3+, reflecting that the non-magnetic Al3+ weakens the carrier exchange between the ferromagnetic clusters. As a result, the thermally activated neighbor transition of small polarons is suppressed. Magnetoresistance effect of LSMAO is enhanced from 21.03% to 59.71% with x increasing from 0 to 0.25, which proves that the doping of Al3+can effectively enhance the magnetoresistance effect of LSMAO.

Film capacitors are the core electronic components of modern power devices and electronic equipment. However, due to the low dielectric constant, it is difficult to obtain high energy storage density (effective energy storage density or discharged energy density) for present film capacitors, leading to a large device size and high application cost. To improve the energy storage density of film capacitors, a nanocomposite approach is an effective strategy via combining high dielectric constant of the ceramic nanoparticles with high breakdown strength of the polymer matrix. Nevertheless, for single-layer structure of 0-3 polymer/ceramic composites, the dielectric constant and breakdown strength are difficult to be effectively enhanced at the same time, which limits the further improvement of energy storage density. To solve this contradiction, researchers have combined the composite film with high dielectric constant and high breakdown strength in a superposition to prepare 2-2 type multilayer composite dielectrics, which can achieve synergistic regulation of polarization strength and breakdown strength to obtain high energy storage density. The optimization of electric field distribution and the synergistic regulation of dielectric constant and breakdown strength can be achieved through mesoscopic and microstructural modulation of multilayer composite dielectrics. In this paper, the research progress of multilayer polymer-based composite dielectrics including ceramic/polymer multilayer structure and all-organic polymer multilayer structure in recent years is reviewed. Effect of multi-layer structure control strategy on the improvement of energy storage performance is emphasized. Moreover, enhancement mechanism of energy storage performance of polymer-based multilayer structure composite dielectric is summarized. Finally, challenges and development directions of multilayer composite dielectrics are discussed.

Densification of ceramic materials by conventional sintering process usually requires a high temperature over 1000 ℃, which not only consumes a lot of energy, but also forces some ceramic materials to face challenges in phase stability, grain boundary control, and co-firing with metal electrodes. In recent years, an extremely low temperature sintering technique named cold sintering process (CSP) was proposed, which can reduce the sintering temperature to below 400 ℃, and realize the rapid densification of ceramic materials through the dissolution- precipitation process of ceramic particles by using the transient solvent in liquid phase and uniaxial pressure. The advantages of CSP, including low sintering temperature and short sintering time, have attracted extensive attention from researchers, since it was firstly reported in 2016. At present, CSP has been applied to the sintering of nearly 100 kinds of ceramics and ceramic-matrix composites, involving dielectric materials, semiconductor materials, pressure-sensitive materials, and solid-state electrolyte materials. This paper firstly introduces the low-temperature sintering techniques’ development history, process and densification mechanism. Then, application of CSP in the field of ceramic materials and ceramic-polymer composites is summarized. Based on differences of solubility, application of CSP mainly on Li2MoO4 ceramics, ZnO ceramics, BaTiO3 ceramics, and their composites preparations are introduced. Auxiliary effect of the transient solvent on cold sintering process is emphatically analyzed. Moreover, the high pressure issue in the cold sintering process and the possible solutions are discussed. At last, future development trend of cold sintering process is prospected.

Ceramic materials are widely used in aerospace, medicine and energy transportation concerned for their excellent over-all mechanical and chemical properties, such as corrosion resistance, high temperature resistance and oxidation resistance. Especially, joining ceramic materials themselves and connecting them with metals are of great significance for the practical engineering applications. Compared with traditional joining technology, electric-assisted joining technology possesses a variety of advantages, such as low temperature and short time, owing to the special influence of the electric field on some ceramic materials. This paper focuses on the development of the electric-field assisted joining technologies of ceramics and ceramic matrix composites, and summarizes their research status in recent years. From the views of joining mechanism, typical interface microstructure and joint strength and influencing factors, the electric-field assisted diffusion bonding (FDB), spark plasma sintering (SPS) joining, and the new low-temperature rapid flash joining (FJ) are reviewed. Moreover, the applicable scope and limitations of different electric-field assisted joining technologies are expounded. In addition, the development trend of the electric-field assisted joining technology of ceramic materials is prospected.

Lithium (Li) metal is one of the most attractive anode materials for the development of high energy density batteries due to its high theoretical specific capacity and low electrochemical potential. However, during the repeated deposition/stripping of Li metal anode, irregular Li dendrite growth inevitably takes place, which seriously affects the cycle life and safety of Li metal batteries. In this study, a simple and mild strategy was developed to in-situ modify the carbon nanotubes with bismuth (Bi) nanoparticles, followed by coating the as-prepared materials on the surface of commercial copper foil as current collector for Li metal anode. It is demonstrated that the in-situ modified Bi nanoparticles promotes the uniform Li deposition, thereby inhibiting the growth of Li dendrites and improving the electrochemical performance of Li metal batteries. Under the current density of 1 mA·cm-2, Coulombic efficiency of Li|Cu cell based on the Bi@CNT/Cu current collector maintains 98% after 300 cycles. Meanwhile, the symmetric cell based on the Li@Bi@CNT/Cu anode can maintain the stable cycling for 1000 h. When it is applied in LiFePO4 (LFP) full cell, the Bi@CNT/Cu current collector also exhibits excellent electrochemical performance, which can retain the stable cycling for 700 cycles at the rate of 1C (170 mA·g-1). This study provides a new strategy for suppressing dendrite growth of Li metal anodes.

Photocatalytic degradation of organic pollutants from water bodies can efficiently reduce the organic pollutants in wastewater, which has broad application prospects. In this study, using CoFe1.95Sm0.05O4 as a support, the Z-scheme heterojunction Ag2S/Ag/CoFe1.95Sm0.05O4 was synthesized through a facile in situ deposition method followed by photo-reduction. Microstructure, phase structure, optical and magnetic properties of the samples were analyzed. Ag2S/Ag/CoFe1.95Sm0.05O4 composite exhibited the highest catalytic activity, which dynamic constant (k) was 1.96, 2.71 and 7.24 times higher than those of Ag2S/Ag, Ag2S and CoFe1.95Sm0.05O4, respectively. Introduction of CoFe1.95Sm0.05O4 could ef?ciently promote the separation ef?ciency of photogenerated charge carriers in Ag2S/Ag. And ?O2-and ?OH- were proved to be the main active substances in the photocatalytic process. In addition, the as-prepared Ag2S/Ag/CoFe1.95Sm0.05O4 composite could be quickly separated from the solution by an extra magnetic field after the photocatalytic reaction. Cyclic photodegradation test showed that the Ag2S/Ag/CoFe1.95Sm0.05O4 hybrid materials had the stable degradation ability and crystal structures in the photodegradation process. This research provides a useful approach to develop photocatalysts with high efficiency, narrow band gap and magnetism.

Perovskite (ABO3) piezoceramics have been developed for several decades, and there are a lot of data available. It is of great significance to find relationships between structure and properties of materials from these data. In this work, experimental data of Curie temperature (Tc) of BiFeO3-PbTiO3-BaTiO3 solid solution of perovskite piezoelectric ceramics was collected to build the model to predict the Tc. From the perspective of thermodynamics, the quadratic polynomial relationship between Tc and reduced mass was introduced but the deviation was relatively large. More descriptors (including element information, physical quantities, space groups number) and SISSO (Sure Independence Screening and Sparsifying Operator) were used for machine learning to find the correlation between Tc and components. Comparing the root mean square error (RMSE) of different descriptors and dimensions, it's found that more descriptors, more fundamental the descriptors are, and larger dimension will result in smaller RMSE to be used. Meanwhile, RMSE of the same number of descriptors in the same dimension are compared. The optimal four-dimensional model is build using six descriptors: reduced mass, the ratio of A- and B-site ion radii, the ratio of A- and B-site unfilled electrons and element contents of Ba, Pb and Bi. RMSE and maximum absolute error (MaxAE) of our model are 0.59 ℃ and 1.38 ℃, respectively. The average relative error (MRE) of external test is 1.00%. Our results indicate that SISSO machine learning based on limited samples is suitable for the predication of Tc of perovskite piezoelectric ceramics.

MgAgSb is a promising room temperature thermoelectric material with relatively abundant element reserves for the construction of high-performance wearable thermoelectric batteries. In this study, Mg-Ag-Sb thin films were prepared on polyimide (PI) substrates by using magnetron sputtering, and the effects of annealing conditions on their thermoelectric properties were systematically investigated. The results showed that the MgAgSb flexible thermoelectric film composed of MgO, Ag3Sb and Sb2O4 multiphases instead of pure phase, in which Ag3Sb played main role of thermoelectric function. Different annealing atmospheres significantly improved the thermoelectric properties of MgO-Ag3Sb-Sb2O4 (Mg-Ag-Sb) flexible thin films, among which the vacuum treatment appeared the best performance. Under vacuum conditions, the thermoelectric properties firstly increased and then decreased with the annealing temperature increasing, and the best thermoelectric property was achieved when the annealing temperature was 573 K, with a power factor of 74.16 μW?m-1?K-2 near room temperature. Moreover, the film exhibited good flexibility, and the conductivity changed by only 14% after 900 bending times. This study provides a reference for the preparation of MgAgSb flexible thermoelectric films and their wearable applications.

It is an effective strengthened technique to introduce a coating containing compressive stress on the surface of ceramic. In this work, the mixed slurry of alumina and quartz powder was coated on the pre-sintered alumina body, then the mullite-alumina coating with lower thermal expansion coefficient was synthesized in-situ after pressureless co-sintering. The pre-stressed strengthening of alumina was achieved by the residual compressive stress formed in the coating during the cooling process. The results indicate that, with the increase of the doping content of quartz in the coating, the flexural strength of pre-stressed alumina increases firstly and then decreases. The flexural strength of specimen realizes the highest value when the doping mass fraction of quartz is 15%, and the interface between the coating and the substrate bonds tightly. Under this condition, the flexural strength of the pre-stressed alumina ceramic is (549.44±27.2) MPa, which is 37.19% higher than that of the common alumina. When the doping mass fraction of quartz is higher than 15%, the flexural strength decreases due to the shrinkage stress mismatch in the sintering process. The effect of prestress enhancement weakens gradually with the increase of temperature. As the testing temperature reaches and exceeds 1000 ℃, pre-stressed alumina and common alumina possess approximately equal flexural strength. Pre-stressed alumina also exhibits better thermal shock resistance and damage tolerance due to the compressive stress formed in the coating

Flash sintering is a sintering technology coupled with temperature field and electric field, with characteristics of rapid mass transfer at low temperature, showing significant advantages in the synthesis of high entropy ceramics. In this study, relatively dense high entropy oxide ceramic (MgCoNiCuZn)O was synthesized by flash sintering, which properties were compared with those of conventional sintered samples. Under flash sintering condition of room temperature, the electric field intensity of 50 V/cm and the current density of 300 mA/mm2, the time of phase transformation is only 10 s. The maximum relative density of flash sintered sample is 94%, which is 22.8% higher than that of conventional sintered sample. The maximum hardness of flash sintered sample is 5.05 GPa, which is 3.95 GPa higher than that of conventional sintered sample. When the frequency is lower than 2 Hz, the dielectric constant of flash sintering sample is one order of magnitude higher than that of conventional sintered sample. The property improvement of flash sintered samples is attributed to the acceleration of mass transfer by the critical electric field to increase the material density, and the extra defects introduced by the critical electric field.

Silica aerogels have wide application prospect in high temperature heat insulation due to their low density and high porosity. However, the brittleness and high cost of supercritical drying restrict their application. In this study, spongy silicone aerogels with high flexibility were prepared via Sol-Gel polymerization and atmospheric pressure drying using vinyltrimethoxysilane (VTMS) and vinylmethyldimethoxysilane (VMDMS) as precursors. The effects of precursor molar ratio on the microstructure and compressive resilience of aerogels, as well as the inorganic transformation process of aerogels in high temperature aerobic and anaerobic environments were studied. The results show that with the increase of VTMS/VMDMS ratio in the precursor, the aerogel particles become smaller and more tightly packed, and the compression resilience of aerogels also decreased. In air at 800 ℃, aerogels were transformed into inorganic SiO2 by oxidation of organic side groups, fracture and rearrangement of main chain Si-O-Si. In N2 at 800 ℃, aerogels were transformed into the mixture of inorganic SiO2 and free carbon by pyrolysis reaction, and after further treatment at 1000-1400 ℃, SiO2 and free carbon were subjected to carbothermal reduction reaction to form amorphous Si-O-C structures such as SiO4, SiCO3, SiC2O2, and SiC3O, and a small amount of β-SiC nanowires. The Si-O-C structure formed by carbothermal reduction reaction at 1200 ℃ has optimal high temperature oxidation resistance, which can provide reference for the preparation of pyro-oxidation resistant Si-O-C aerogels.

Joining technology has become an important part of the preparation and engineering application of large or complex-shaped Cf/SiC composites. In this study, the stable joining of Cf/SiC composites was achieved via the Si-C reaction joining method by using the phenolic resin as the carbon precursor. Effects of the bulk density and pore size of porous carbon blanks on the joining properties and microstructure of the joints were investigated. Effect of the content of inert fillers on the joining properties and microstructure of joint were discussed. Bulk density and pore size of the resin-based porous carbon blank are suitable to be set in the range of 0.71-0.90 g·cm-3 and 200-600 nm, respectively. The size of free silicon increases gradually with the increase of the pore size. The flexural strength of the joined specimens can reach (125±12) MPa at pore size of 190 nm. Addition of SiC inert filler is obviously beneficial to reduce the volume shrinkage of the porous carbon blank. Flexural strength of the joined specimens reached the highest value, i.e., (216±44) MPa at the inert filler content of 50%. Overall, this study provides theoretical guidance for the stable joining of Cf/SiC composites, which has significance for realizing the preparation and engineering application of complex-shaped or large Cf/SiC composites.

Environmental barrier coating (EBC) is essential for protection of ceramic matrix composite hot-sections in future gas turbine engines with high thrust-to-weight ratio. Rare-earth silicates, such as Yb2SiO5 and Yb2Si2O7, have been developed for potential application as EBC. However, the corrosion behaviors and mechanisms of EBC in molten salt environment such as Na2SO4 at high temperature are not clear. In this work, the Yb2SiO5/Yb2Si2O7/Si coating was prepared by vacuum plasma spraying (VPS). The molten salt (Na2SO4+25% NaCl, in mass) corrosion behaviors and mechanisms of the coating at 900 ℃ for 60-240 h were investigated. Results showed that the Yb2SiO5/Yb2Si2O7/Si coating exhibited dense structure with good bonding between the triple ceramic layers. The molten salt of Na2SO4+25% NaCl penetrated the Yb2SiO5 top layer and enriched in the Yb2Si2O7 interlayer, while the interfacial bonding between the coating and substrate still remained good after corrosion for 240 h. The Yb2SiO5 phase in the top layer exhibited good stability, while the second phase of the Yb2O3 reacted with molten salt. The content of the Yb2O3 decreased with the increase of corrosion time. The Yb2Si2O7 phase in the interlayer reacted with molten salt to form apatite phase of NaYb9Si6O26 and sodium silicate as well as volatile species such as Cl2 and SO2, which might shorten the service life of the coating. Moreover, there was almost no molten salt in the silicon bond layer, which remained intact. The Yb2SiO5/Yb2Si2O7/Si coating exhibited good resistance to molten salt corrosion.

LaMeAl11O19 ceramics is a kind of thermal barrier coating (TBC) material with promising application prospect due to its unique crystal structure, excellent thermodynamic properties, low thermal conductivity, and high temperature phase stability. Here, LaMeAl11O19/YSZ (Me=Mg, Cu, Zn) thermal barrier coatings were prepared by atmospheric plasma spraying (APS). Failure analysis of the coating was carried out by burner rig test and other analysis techniques. The results show that LaMgAl11O19 (LMA), LaZnAl11O19 (LZA) and LaCuAl11O19 (LCA) powders are decomposed during the plasma spraying, resulting in different contents of magnetoplumbite phase in the coatings, which may be an important factor responsible for their distinction of thermal cycling lifetimes. The LaMeAl11O19 layer is delaminated upon YSZ layer due to mismatch of thermal expansion coefficient between LaMeAl11O19 layer and YSZ layer and volume shrinkage caused by recrystallization of amorphous phase. Then the YSZ layer is exposed high temperature, accelerating sintering and TGO growth, and promoting the delamination of the YSZ layer from the bond coat. At low temperature, with the increase of the atomic number of the divalent Me2+, the thermal conductivity of the LaMeAl11O19 decreases. At high temperature, LCA coating has better infrared emissivity (0.88, 600 ℃) than both LMA and LZA, which weakens the contribution of photon conduction to thermal conductivity and leads to the reduction of thermal conductivity. Therefore, LCA coating has potential application in high temperature infrared radiation coating.

In recent years, Chinese researchers have done a myriad of representative works in the field of rational design and construction, surface functional engineering, optimization and mechanism exploration of physicochemical properties, and biomedical applications of materdicine and medmaterials. To showcase the state-of-the-art research achievements of Chinese scientists in the field of materdicine and stimulate the interest of all walks of life in materdicine and medmaterial, the Editorial Board of the Journal of Inorganic Materials herein invited Prof. CHEN Yu from Shanghai University as guest editor to compile this Special Issue themed “Medmaterials”. This issue contains the latest reviews and research papers related to medical materials, including piezoelectric semiconductor nanomaterials, group VA single- element two-dimensional materials, bioactive ceramics, metal alloys, and silica-based micelles. It is hoped that this special issue will promote the cooperation of researchers and scientists from many fields with different disciplinary backgrounds, and jointly promote the development of the field of materdicine and medmaterial, so as to revolutionize the diagnosis and treatment of various diseases in clinical medicine for the benefit of human health.

Ceramic fibers are the vital high-temperature thermal insulating materials due to their excellent mechanical property, high-temperature stability and thermal shock resistance. However, practical application of traditional ceramic fiber membranes in the field of thermal insulation are greatly limited by their high thermal conductivities at high-temperatures. In this work, SiZrOC nanofiber membranes with high infrared shielding performance were prepared by electrospinning technique. The SiZrOC nanofibers were composed of SiO2, ZrO2, SiOC, and free carbon phase with average diameter of (511±108) nm. The SiZrOC nanofiber membranes exhibited possess excellent high-temperature thermal insulation performance. Thermal conductivity of SiZrOC nanofiber membranes at 1000 ℃ reached 0.127 W·m-1·K-1, obviously lower than that of other traditional ceramic fibers. In addition, the as-prepared SiZrOC nanofiber membranes exhibited high strength, good flexibility and excellent high-temperature stability, so they had great potential for high-temperature thermal insulation. Therefore, preparation strategy of SiZrOC nanofiber membranes also provides a new route for designing other high-performance thermal insulators.

Ultra-high temperature composite ceramic matrix composites ZrC-SiC, ZrB2-ZrC-SiC and HfB2-HfC-SiC were fabricated by precursor infiltration and pyrolysis method. The ultra-high temperature ceramic phases in the materials were characterized by submicron/ nanometer uniform dispersion distribution. Ablation behaviors of ZrC-SiC, ZrB2-ZrC-SiC and HfB2-HfC-SiC matrix composites under atmospheric plasma and on-ground arc-jet wind tunnel were investigated comparatively. The main factors that affect design for ultra-high temperature composite ceramic matrix composites were summarized. The result shows that, compared with traditional SiC-based composites, ultra-high temperature composite ceramic matrix composites have a solid-liquid two-phase dense oxide film formed in situ on the surface of the composites after ablation. Synergistic effect of the two phases has achieved effects of erosion resistance and oxidation resistance, which plays a very important role in hindering the loss of liquid SiO2 and greatly improves the ultra-high temperature ablation performance of the materials. On this basis, the important factors that should be considered in the matrix design of ultra-high temperature composite ceramic matrix composites are obtained. The above results have instructional significance for the ultra-high temperature and the limited life application of ceramic matrix composites.

Multiferroic material is one of hot spots in the materials research area which can be widely used in many new functional devices. Barium titanate (BaTiO3, BTO) has attracted many interests for its multiferroic properties, such as ferroelectricity, high dielectric constant and electro-optical properties at room temperature. The BaTi0.94(TM1/2Nb1/2)0.06O3 (TM=Mn/Ni/Co) ceramic samples were prepared by solid state reaction method, and their structure, electrical, magnetic, and optical properties were systematically studied. The crystal structure of all doped samples changes from tetragonal to cubic phase without any hexagonal phase depending on ionic radius. Weakening of Raman scattering peaks of BTO tetragonal phase further proves the phase transition to cubic phase caused by doping. The Curie temperature (TC) has a dramatic decrease with the dopant as the phase transition from tetragonal phase to cubic phase. Although the ferroelectricity is weakened, it is still existed. The magnetic measurement suggests that Ni-Nb doped sample has the strongest ferromagnetism among different dopants which can be deduced by the F-center exchange (FCE) theory. Furthermore, energy gaps of BaTi0.94(TM1/2Nb1/2)0.06O3 are obviously reduced compared to that of BTO, which can be reasonably explained by impurity level and band theory. These results indicate that BTO based multiferroic ceramics with ferroelectric and ferromagnetic coexisting at room temperature can be obtained by B-site co-doping, which can be expected to be widely used in multiferroic functional devices.

Defects at the surface and grain boundary of the three-dimensional (3D) organic-inorganic metal halide perovskite film incline to cause non-radiative recombination of charge carriers and accelerate decomposition of 3D perovskite, in turn deteriorating the power conversion efficiency (PCE) and stability of the perovskite solar cells (PSCs). In this study, the organic 4-chlorobenzylamine cation was applied to react with 3D perovskite and the residual PbI2 to in-situ form a two-dimensional (2D) perovskite top layer, which can passivate the surface and grain boundary defects of the 3D perovskite film, and improve the surface hydrophobicity. Based on this strategy, 2D/3D-PSCs with higher PCE and better stability were successfully obtained. Their structure, morphology photoelectric propery and stability of PSCs were systematically studied. All results show that 2D/3D-PSCs achieve PCEs up to 20.88%, much higher than that of 18.70% for the 3D-PSCs. In addition, 2D/3D-PSCs can maintain 82% of the initial PCE after 200 h continuous operation under 1-sun illumination in N2 atmosphere, exhibiting excellent stability.

Decomposition of cyclohexyl hydroperoxide (CHHP) is an important step in the preparation of cyclohexanol and cyclohexanone by non-catalytic oxidation of cyclohexane. Using Co3O4 nanoparticles as the core, cetyltrimethylammol/lonium bromide (CTAB) as the template and tetraethyl orthosilicate (TEOS) as the silicon source, the core-shell structure material Co3O4@SiO2 was synthesized by template method. The effects of the preparation conditions for SiO2 shells on the structure of core-shell material were investigated, such as the ratio of ethanol to water, the concentration of CTAB and the amount of TEOS. Textural properties of the materials were characterized by different techniques. Meanwhile, the catalytic performance and stability of the materials were evaluated on the decomposition reaction of CHHP. All results showed that the materials with thin shell and high porosity exhibited a preferable catalytic performance, and the conversion of CHHP was 81.68% and the selectivity of cyclohexanol and cyclohexanone was 70.60% and 34.06%, respectively. This core-shell structure could protect the activity of the core Co3O4 and significantly decrease the loss of cobalt element. However, there existed different degree of the fragmentation of SiO2 shell in the recycling process of Co3O4@SiO2 samples.

Removal of organic pollutants from water bodies by photocatalysis has broad application prospects in the field of sewage purification. In this study, the quaternary BiMnVO5 was synthesized by hydrothermal method and solid-state reaction, respectively. The morphology, structure and optical properties of the catalysts were characterized, and the electronic structure was calculated. Results showed that the hydrothermal method can rapidly synthesize pure BiMnVO5 with high crystallinity. BiMnVO5 is a semiconductor with a direct band gap of 1.8 eV, which is consistent with the results of first-principles calculations. Analysis of the density of states further reveals that the optical absorption band are attributed to the transitions from Mn3d/O2p to V3d. The photocatalytic results show that the BiMnVO5 synthesized by hydrothermal method exhibits the highest catalytic activity. About 98% Methylene Blue (MB) is degraded when exposed to visible light for 4 h. The hydroxyl radicals and photo-generated holes are proved to be the main active substances in the photocatalytic process. After 5 cycles, it still maintains capacity of degrading 85% MB in 4 h under visible light irradiation, while its morphology and structure remain unchanged, which indicates BiMnVO5 a good photocatalyst with reliable stability.

In this study, the first-principles method was used to predict the vacancy ordered structures of ternary Hf-Ta-C system and the effect of vacancy on its mechanical properties. Crystal structure of (Hf, Ta)C1-x under ambient pressure were predicted by first-principles evolutionary using USPEX software. This calculation found 5 stable and 3 metastable vacancy ordered structures which all share the rock-salt structure. Then, mechanical properties of (Hf, Ta)C1-x vacancy ordered structures were calculated by the first-principles method, and change of mechanical properties with the concentration of vacancy was analyzed. They all showed high bulk modulus, shear modulus, elastic modulus, and Vickers hardness. Their moduli and hardness decreased with the increase of the concentration of vacancy at the same Hf/Ta ratio. Finally, their electronic density of states are calculated, revealing that their chemical bonding is a mixture of strong covalence and weak metallic. Data from this study are promising for understanding vacancy ordered structures, mechanical properties and applications of Hf-Ta-C system.

Ozone pollution is taking more dominant position in China than PM2.5, traditional ozonolysis catalytic materials have limited performance in humid conditions. In this study, an iron-doped basic nickel carbonate catalyst (NiCH-Fe) was successfully fabricated via a facile hydrothermal method, which could stably decompose 2.14 μg/L ozone at 60% relative humidity for 12 h with nearly 100% removal ratio. The result of the Quartz Crystal Microbalance test showed that the water molecules adsorbed on the surface of NiCH-Fe were significantly reduced as compared with that adsorbed on pure NiCH, which were favorable for the competitive adsorption of ozone. Density functional theory results proved that Fe atoms were new sites instead of Ni atoms and had stronger adsorption capacity for ozone molecules. In addition, the XPS results demonstrated that the iron atoms serving as active sites were substantially stable in the reaction. Therefore, material doped with Fe provided excellent moisture resistance and long-term stability. This work provides an effective technical method for the development of materials with high moisture resistance ability for efficient ozone catalytic decomposition.

Using carbon nitride photocatalysts to catalyze the selective conversion of biomass platform molecules could not only expand the application fields of non-metallic catalysts but also alleviate the dependence on fossil energy in chemical manufacturing. 2,5-diformylfuran is an indispensable intermediate for the production of value-added chemicals. In this study, pyromellitic dianhydride and melem were used as the precursors. The pyromellitic dianhydride monomer was incorporated into the carbon nitride skeleton by high-temperature heat-treatment, and the catalysts were further treated with H2O2. Finally non-metallic carbon nitride photocatalysts containing nitrogen hydroxyl groups were prepared. Moreover, its performance in the selective oxidation of 5-hydroxymethylfurfural into 2,5-diformylfuran under visible light excitation was investigated. The results showed that H2O2-treated samples could generate nitroxide radicals under light irradiation, resulting in the selective oxidation of hydroxyl groups on the side chains of 5-hydroxymethylfurfural molecules into aldehyde groups, avoiding undesired side-reactions (ring-opening, mineralization reactions, etc.) caused by various reactive oxygen species that may be generated in aqueous solutions. In particular, under the excitation of an LED light source with a specific wavelength (400 nm), when the ratio of melem to PMDA precursor was 1 : 2, the selectivity of 2,5-diformylfuran over the photocatalyst could reach 96.2%.

Since the beginning of the 21st century, energy shortage and environmental pollution have been the major challenges faced by human beings. Photocatalytic carbon dioxide (CO2) reduction is one of the promising strategies to solve the energy crisis and promote the carbon cycle, in which semiconductor captures solar energy to obtain hydrocarbon fuel. However, the low activity and poor selectivity of the products greatly limit the practical application of this technology. Thus, it is of great significance to regulate product selectivity, improve photocatalytic efficiency, and deeply understand the mechanism of CO2 reduction reaction. In recent years, ultrathin materials have attracted extensive attention from researchers due to their high specific surface area, abundant unsaturated coordination surface atoms, shortened charge migration path from inside to surface, and tailorable energy band structure, and have achieved promising results in the field of photocatalytic CO2 reduction. In this paper, the reaction mechanism of photocatalytic CO2 reduction is firstly summarized. Next, the research results of promoting electron hole separation and regulating charge transport path of ultrathin nanostructures by constructing heterostructures, designing Z-scheme systems, introducing co-catalysts, and defect engineering are introduced. Finally, the prospect and challenge of improving the efficiency of photocatalytic CO2 reduction and optimizing the product selectivity are pointed out.

The electrocatalytic carbon dioxide reduction reaction can convert the greenhouse gas carbon dioxide into chemical raw materials or organic fuels, providing a feasible way to overcome global warming and the conversion of electrical energy to chemical energy. The main challenge of this technology is the wide product distribution, resulting in low selectivity of a single product, however, modulating the surface properties of the catalyst is an efficient strategy to solve this problem. In this study, the precursors of Cu2O and Cu2S were oxidized to the CuO catalysts with different surface properties. The CuO-FS catalyst derived from Cu2S delivered the improved activity of electro-reduction of carbon dioxide and selectivity for formic acid product. This catalyst exhibited a higher total current density and the Faraday efficiency of formic acid > 70% in a wide test voltage range of -0.8 - -1.1 V; the Faraday efficiency for formic acid could reach a maximum of 78.4% at -0.9 V. The mechanism study indicated that the excellent performance of CuO-FS for electro-reduction of carbon dioxide could be attributed to the large electrochemically active surface area, which provided a large number of surface active sites, resulting in a higher total current density; moreover, the less zero-valent Cu was produced over the surface of CuO-FS during the electrocatalytic process, which reduced the production of ethylene and thus promoted the production of formic acid.

Highly light absorptive photocatalysts are of great significance to boost the photothermal conversion efficiency. Light trapping effect of nanoarray structured photothermal catalysts can enhance the light absorption and improve the photothermal conversion efficiency. However, the practical applications of array-based catalysts are hindered by very low loadings of active metal catalysts per unit illumination area. Herein, we develop a SiO2-protected MOFs pyrolysis method for the preparation of powder-form cobalt plasmonic superstructures that enable a 90% absorption efficiency of sunlight and tunable metal loading per unit area. Its high light absorption capacity was confirmed by time-domain finite-difference simulation calculations due to the plasmonic hybridization effect of nanoparticles. Compared with nanoarray-structured plasmonic superstructures, the powder-form catalyst exhibit enhanced catalytic activity and stability, resulting in the increase of CO2 conversion efficiency from 0.9% to 26.2%. This study lays the foundation for the practical application of non-precious metal photothermal catalysts.

Conversion of CO2 into fuels by photocatalysis is promising in solving the energy crisis and the greenhouse effect. Among various photocatalytic materials, Zn1-2x(CuGa)xGa2S4 materials possess visible light response and high conduction band potential, which are ideal CO2 reduction materials from thermodynamics aspect. However, their photocatalytic CO2 reduction activity is still low which is urgent to improve its activity in terms of kinetics. In this study, Zn0.4(CuGa)0.3Ga2S4 was synthesized and composited with CdS nanoparticles with different proportions to form Zn0.4(CuGa)0.3Ga2S4/CdS heterojunction photocatalysts. A series of characterizations suggest that CdS is uniformly grown on surface of Zn0.4(CuGa)0.3Ga2S4 microcrystals to form a Z-scheme type all-solid heterojunction composite materials. Such a structure effectively suppresses the recombination of electron-hole pairs and improve the photocatalytic performance. In the solution CO2 reduction system, the as-prepared Zn0.4(CuGa)0.3Ga2S4/CdS can effectively reduce CO2 into CO under visible light irradiation. The optimal molar ratio of Zn0.4(CuGa)0.3Ga2S4 and CdS in composite materials is 2 : 1, whose photocatalytic performance is 1.7 times of that of Zn0.4(CuGa)0.3Ga2S4/ CdS and 1.6 times of that of CdS. This work constructs all solid Z-scheme type Zn0.4(CuGa)0.3Ga2S4/CdS heterojunction materials with enhanced photocatalytic activity for CO2 reduction, which is promising for designing novel photocatalysts in field of artificial photosynthesis.

Rapid and high-throughput experimental methods are of great significance to the development of material genetic engineering technology. High temperature heat treatment is a necessary part for the preparation of inorganic non-metallic materials, while the rapid heat treatment technology of materials library needed for material genetic engineering is still blank. Here we report the multi-laser-beam parallel heating system which can be used in rapid high temperature treatment for samples arranged in an array of {A′B}, named as materials library. We introduce the design principle, operation mode, structure details, and software of the multi-laser-beam parallel heating system. The facility presents many advantages of independent adjustment of laser heating time, power and spot size for each beam and high automation. The maximum laser power is above 100 W, and the maximum stable heating temperature is ~2000 ℃ for each laser beam. As a typical application demonstration, a series of sintering experiments of Y3Al5O12:Ce (YAG:Ce) luminescent ceramics were carried out. Their heating temperature was 1400 ℃, 1500 ℃ and 1600 ℃, while their holding time was 180, 360 and 540 s, respectively. Above facility operated automatically according to the pre-set heating positions and heating curves. All results show that, using the multi-laser-beam parallel heating system, fully-sintered samples with good crystallinity and luminescence properties can be obtained within several minute heat treatment, while the conventional sintering technology needs more than 10 h. This study may provide a new technical solution for processing condition screening and high-throughput preparation of multi-samples in an energy and time saving mode.

Metal sulfide Ag2S is an attractive semiconductor due to its excellent physical and chemical property that enable it with wide applications in fields of catalysis, sensing, optoelectronics in past years. In present work, ?18 mm× 50 mm Ag2S ingot was successfully prepared using zone melting method and its thermoelectric (TE) behavior was investigated. Ag2S has standard monoclinic P21/c space group (α-Ag2S phase) below 450 K and transfer to cubic structure (β-Ag2S phase) over this temperature. Ag2S is a n-type semiconductor as the Seebeck coefficient S is always negative due to the Ag interstitial ions in the material that can provide additional electrons. S is about -1200 μV·K-1near room temperature, declines to -680 μV·K -1 at 440 K and finally decreases to ~-100 μV·K -1at β-Ag2S state. The electrical conductivity (σ) of α-Ag2S is almost zero. However, the value sharply jumps to ~40000.5 S·m -1 as the material just changes to β-Ag2S at 450 K and then gradually deceases to 33256.2 S·m -1 at 650 K. Hall measurement demonstrates that carrier concentration nH of Ag2S is suddenly increased from the level of ~10 17 cm-3 to ~1018 cm-3during phase transition. Total thermal conductivity κ of α-Ag2S is ~0.20 W·m -1·K-1 but is ~0.45 W·m-1·K-1of β-Ag2S. Ultimately, a maximum ZT=0.57 is achieved around 580 K that means Ag2S might be a promising middle-temperature TE material.

Soft magnetic alloy is the core material of the proton/heavy ion accelerator. To reduce the eddy current loss at high frequencies, the insulating coating needs to be coated on the surface of soft magnetic alloy, and to be followed-up heat treatment (~600 ℃) to lower the residual stress from defects and dislocations produced in the cold forming process of soft magnetic alloys. Therefore, the insulation coating for soft magnetic alloy should meet the requirement of high-temperature resistance. SiO2 is one of the most common inorganic coating materials, which has good insulation performance and temperature resistance, so it is especially suitable for high-temperature insulation coating. In this work, fabrication process of SiO2 insulating coating was systematically studied. The silane coupling agent 3-glycidyloxypropyltrimethoxysilane (KH-560) was added to the phytic acid-catalyzed tetraethyl orthosilicate (TEOS) and methyltriethoxysilane (MTES) sol to improve the film-forming property. Effect of KH-560 on structure and property of SiO2 coating was analyzed in detail. The results showed that the stability and the film-forming property were improved effectively via adding a reasonable amount of KH-560. When adding amount of KH-560 is 0.04 mol, the as-preared SiO2 coating exhibites excellent film-forming characteristics, corrosion resistance and electrical insulation with sheet resistance of 2.97×1011 Ω/□ at 100 V.

Sn based materials, as low-cost and earth-abundant electrocatalysts, are potential candidates for CO2 reduction reaction (CO2RR) into liquid fuels. Unfortunately, the low selectivity and stability limits their applications. Herein, we developed an electrocatalyst of Sn quantum dots (Sn-QDs) for efficient, durable and highly selective CO2 reduction to HCOOH. The Sn-QDs were con?rmed with high crystallinity and an average size of only 2-3 nm. Small particle size endowed the electrocatalyst with improved electrochemical active surface area (ECSA), which was about 4.4 times of that of Sn particle. This enlarged ECSA as well as accelerated CO2RR kinetics favored the electrochemical conversion of CO2. The Faradaic ef?ciency of HCOOH (FEHCOOH) on Sn-QDs/CN reached up to 95% at -1.0 V (vs RHE), which exceeded 83% in the recorded wide potential window of 0.5 V. Moreover, the Sn-QDs electrocatalyst exhibited good electrochemical durability for 24 h.

Nickel phyllosilicates have shown considerable potential in many fields such as electrochemistry and catalysis owing to their specific structures, attracting a great attention on preparation and properties of them in recent years. In this study, Ni3Si2O5(OH)4 microspheres were synthesized via a hydrothermal method by using NiCl2 and tetraethyl orthosilicate (TEOS) as the raw materials. Effects of Ni/Si molar ratio and alkali source on the phase composition, morphology and textural property of the products were investigated. Under optimized conditions, the as-synthesized Ni3Si2O5(OH)4 microspheres presented a nanosheets-assembled morphology with an average diameter of ca. 2.5 μm, SBET of 119.6 m2·g-1, pore volume of 0.673 cm3·g-1, and Zeta potential measurements showed that they were negatively charged with pH ranging from 3 to 10. When employed as the adsorbents for basic fuchsin (BF), the Ni3Si2O5(OH)4 microspheres showed an adsorption capacity of 120.7 mg·g-1 with the removal efficiency up to 96.6% from 50 mg·L-1 solution, superior to most of the referred adsorbents in literatures, and the adsorption kinetic data can be well interpretated via the pseudo-second-order model. Data of the relationship between equilibrium adsorption capacity and BF concentration were well fitted by Freundlich isotherm model with the 1/n value of 0.1678, indicating that the surface was heterogeneous and the adsorption strength was strong.

Electrochemical reduction of the greenhouse gas CO2 in solid oxide electrolysis cells (SOECs) has attracted much attention due to their high energy conversion efficiency and great potential for carbon cycling. Compared with the asymmetrical configuration, symmetrical SOECs with the same material as anode and cathode, can greatly simplify the fabrication process and reduce the complication associated with varied interfaces. Perovskite oxides LaxSr2-xFe1.5Ni0.1Mo0.4O6-δ (LxSFNM, x=0.1, 0.2, 0.3 and 0.4) are prepared and evaluated as symmetrical electrodes in solid oxide electrolysis cells for electrochemical reduction of pure CO2. The polarization resistances are 0.07 Ω?cm2 in air and 0.62 Ω?cm2 in 50% CO-50% CO2 for L0.3SFNM electrode at 800 ℃. An electrolysis current density of 1.17 A?cm-2 under 800 ℃ at 1.5 V is achieved for the symmetrical SOECs in pure CO2. Furthermore, the symmetrical cell demonstrates excellent stability during the preliminary 50 h CO2 electrolysis measurements.

Metal-organic frameworks (MOFs) are widely used in biomedicine due to their porous structure, high specific surface area, abundant functional groups with metal active sites, good biocompatibility, and suitable degradability. In this study, a multifunctional composite nanoparticle (Fe(VI)@PCN@BSA) was prepared for combined photodynamic and chemodynamic therapy of tumors, which was constructed by loading potassium ferrate (K2FeO4, Fe(VI)) in porphyrin-based MOFs (PCN-224) and following a surface coating with biocompatible bovine serum albumin (BSA). The results showed that the particle sizes of PCN-224 and Fe(VI)@PCN@BSA nanoparticles were about 90 nm and 100 nm, respectively. Interestingly, Fe(VI)@PCN@BSA nanoparticles could catalyze H2O2 to produce ?OH under a simulating tumor environmental condition. Meanwhile, they catalyzed to decompose H2O2 to produce O2, and thereby increased the production of singlet oxygen (1O2) under 660 nm laser irradiation, which enhanced the photodynamic effect. More importantly, in vitro evaluation indicated that Fe(VI)@PCN@BSA nanoparticles were biocompatible, and exhibited enhanced photodynamic and chemodynamic combined therapeutic efficacy against tumor cells. Hence, Fe(VI)@PCN@BSA nanoparticles have a great potential application in tumor therapy.

In this research, a facile “in-situ reduction” strategy was developed to construct silver clusters-loaded silica-based hybrid nanoparticles (Ag@SHNPs). Firstly, the formation of organosilica-micellar hybrid nanostructure was achieved by self-assembly of amphiphilic block copolymer PS89-b-PAA16 and hydrolysis, and polycondensation of (3-mercaptopropyl)trimethoxysilane (MPTMS) on the hydrophilic PAA segment. Then, the abundant thiol groups in the organosilica framework were used as reduction sites to in-situ convert the silver salt into silver clusters, and finally the Ag@SHNPs were obtained. Morphology, structure and composition of the hybrid nanoparticles were analyzed, and their cytotoxicity on different cell lines were explored, showing good biocompatibility. The surface enhanced Raman scattering (SERS) activity of the Ag@SHNPs substrate were detected by using 4-mercaptobenzoic acid (4-MBA) as the probe molecule. Under an excitation wavelength of 532 nm laser, 4-MBA-labeled Ag@SHNPs exhibited obvious Raman enhanced signal with an enhancement factor of about 105. Therefore, the silica-based hybrid substrate material shows potential application prospects in SERS bioimaging and high-sensitivity detection.

Aiming at the performance-limiting characteristics of short hole diffusion length (2-4 nm) and sluggish water oxidation kinetics in hematite (α-Fe2O3), we developed hematite nanobelts containing ordered oxygen vacancies by catalyzed oxidation of palladium nanocrystals for efficient photoelectrochemical (PEC) water splitting. Morphologies and structures of as-prepared films were characterized by different methods. Results show that ordered oxygen vacancies was observed in hematite nanobelts with a periodicity of 1.48 nm corresponding to ten times of (11ˉ2) interplanar spacing. The PEC performance of the hematite nanobelts exhibits stable photocurrent density of 3.3 mA·cm-2, the corresponding hydrogen evolution rate of 29.46 μmol·cm-2·h-1, and an early onset potential of 0.587 V (vs. RHE) without additional oxygen evolution reaction cocatalysts. The enhanced performance can be attributed to the introduced ordered oxygen vacancies which can increase the carrier density, greatly accelerate the surface holes transfer, and act as surface active sites to significantly promote the surface water oxidation reaction.

How to design and fabricate highly efficient and stable Pt nano-catalyst is of important practical value and scientific significance for improving the C=O hydrogenation selectivity of cinnamaldehyde. In present study, a series of MgAl hydrotalcite (LDH) supports with various morphologies were synthesized by co-precipitation and hydrothermal methods. The supported Pt/LDH catalysts were prepared by incipient wet impregnation (IMP) method with LDH supports, and used for cinnamaldehyde selective hydrogenation reaction, and influences of LDH with different morphology for the catalyst activity were studied. The structure, morphology, surface physicochemical properties of these catalysts were characterized. The results show that the morphology of different supports exerts a significant influence on the structure and properties of Pt/LDH catalysts. Interaction between lamellae LDH nanosheet and active component Pt facilitates dispersing and stabilizing of Pt nanoparticles. Meanwhile, there are abundant alkaline sites and surface hydroxyl groups in the LDH support, which are beneficial to improve the catalytic hydrogenation activity and stability. Results of catalytic performance show that selectivity of cinnamon alcohol (CMO) and conversion of cinnamon aldehyde (CMA) at reaction temperature of 40 ℃, reaction pressure of 1 MPa, and reaction time of 120 min were 82.1% and 79.8%, respectively. After 5 rounds of cycle tests, the Pt/LDH catalyst still has excellent stability.

As a common air pollutant, nitrogen dioxide (NO2) gas does serious harm to the natural environment and human health. Therefore, it is imperative to develop efficient detection methods for detecting such toxic and harmful gases. Developing a new type of composite film gas sensor to achieve high selectivity and high sensitivity detection of nitrogen dioxide at room temperature has become a research hotspot. Here, we prepared zeolitic imidazolate framework 8 /reduced graphene oxide (ZIF8/rGO) composite with porosity and large specific surface area through chemical precipitation and ultrasonic method. Based on this materials, an NO2 sensor was constructed and then evaluated at room-temperature. Its possible mechanism of sensing NO2 was explored. The results showed that ZIF8/rGO sensor presented a response of 34.77% toward 50×10-6 NO2, which was 3.2-fold of pure rGO senor. Meanwhile it exhibited excellent repeatability after 4 reversible cycles with the relative standard deviation (RSD) only 3.9% and remarkable long-term stability in four-week test with the RSD of 2.5%, accompanied outstanding selectivity toward NO2 and a low limit of detection of 3.8×10-8. These hypersensitive properties at room temperature were attributed to its porous structure and large specific surface and high performance of rGO. This work offers a new idea for efficiently detecting poisonous NO2 based on ZIF8/rGO.

Lead zirconate titanate (PZT)-based piezoelectric ceramics are a type of functional material with a wide range of applications, which can be used in ultrasound transducers, piezomotor, medical ultrasound transducer, and surface acoustic wave filter, etc. Improving the piezoelectric property of PZT-based piezoelectric ceramics through modification has always been a research hotspot in this field. In this work, Sm-0.25PMN-0.75PZT piezoelectric ceramics near the morphotropic phase boundary (MPB) were fabricated by conventional solid-phase reaction method, and its microstructure and macroscopic property were systematically studied. The research results show that introduction of Sm3+ can enhance the local structural heterogeneity of piezoelectric ceramics, accelerate the dielectric response, and improve the piezoelectric performance. When Sm3+ is excessively introduced, the long- range continuity of ferroelectric polarization is interrupted in a large area while the piezoelectric performance decreases. The performance of the optimal composition piezoelectric ceramic obtained in this experiment is: high voltage electric coefficient (d33~824 pC/N), high voltage electric voltage constant (g33~27.1×10-3 m2/C), and relatively high Curie temperature (TC~178 ℃). The electrostrain is less than 5% in the range of room temperature to 150 ℃, with relatively good temperature stability. Therefore, this PET-based relaxor-ferrelectric ceramic is a high- performance piezoelectric material with great application prospects.

Refining ceramic microstructures to nanometric range to minimize light scattering provides an effective methodology for developing novel optical ceramic materials. In this study, we reported the fabrication and properties of a new nanocomposite optical ceramic of Lu2O3-MgO by using nano powders synthesized via Sol-Gel method and hot-pressing sintering technology. Influence of powder synthesis conditions and hot-pressing sintering process on the microstructure of the sample was investigated, and the theoretical transmittance of the sample was calculated and compared with the measured transmittance. The results show that the Lu2O3-MgO ceramic fabricated by optimizing process exhibts a homogeneous phase domain distribution, a fine-grain size of 123 nm, a high transmittance of 84.5%-86.0% over the 3-5 μm wavelength range, close to the theoretical transmittance, and enhanced hardness value of 12.2 GPa, toughness value of 2.89 MPa·m-1/2 and bending strength value of (221±12) MPa, indicating potential application in infrared transparent window material.

Luminescent anti-counterfeiting has characteristics of visibility and convenience, which is a popular method in many anti-counterfeiting technologies. However, this anti-counterfeiting luminescent materials have the shortcomings of single emission color and static anti-counterfeiting pattern, leading to easy imitablity. It is urgent to develop new luminescent materials that can achieve dynamic and more reliable anti-counterfeiting performance. In this research, the multicolor persistent luminescence material, chromium doped zinc gallogermanate, was prepared by hydrothermal method. Its persistent luminescence property and dynamic anti-counterfeiting application potential were investigated. Experimental results show that the emission intensity in blue-green and red light regions can be adjusted by changing the raw materials ratio of gallium to germanium. Under the excitation of 254 and 365 nm UV light, a series of samples are observed to be white and red, respectively, indicating multi-mode luminescence characteristics. Furthermore, the decay rate of blue, green and red components in white afterglow is different, so the afterglow color can change dynamically over time. Anti-counterfeiting patterns, designed based on this multicolor afterglow features, improves the security through dynamic change of afterglow color in the time dimension, demonstrating the potential application in dynamic anti-counterfeiting.

The three-dimensional layered compound MAX phase has excellent mechanical property of both metals and ceramics, which is generally considered as a kind of high safety structural materials. In recent reports, V2(Sn, A)C (A = Fe, Co, Ni and Mn) materials showed that antiferromagnetic property can be obtained by inserting the subgroup elements into A layer of MAX phase by molten salt method. However, how to further regulate magnetic properties of MAX phase through design of its crystal structure has attracted the attention of scholars in the field of spintronics and other fields. In this work, four new MAX phases of (V, Nb)2(Sn, A)C (A = Fe, Co, Ni and Mn) were synthesized based on M/A double solid solution by molten salt method, and proved to be synthesized successfully. Magnetic property of the MAX phases was checked by SQUID (superconducting quantum interference device magnetometer). It is found that the change of Curie temperature is correlated with tetragonal ratio (c/a) and elemental composition. Changes of lattice parameters, tetragonal rate and magnetic results before and after introducing Nb element into M site were further compared. Besides, the Hc and Mr of (V, Nb)2(Sn, Fe)C, (V, Nb)2(Sn, Ni)C, and (V, Nb)2(Sn, Mn)C decreased and the Mr increased compared with V2(Sn, A)C (A = Fe, Ni, Mn) before introducing Nb element into M site. All these results were opposite after introducing Nb element into M site of V2(Sn, Co)C which reveals the influence of M/A-site doble solid solution to the magnetic property of MAX phase, and provides a new way for tailoring magnetic property of MAX phase.

The high-throughput preparation of material library can quickly obtain a large number of samples with quasi-continuous or gradient change of composition by parallel synthesis strategy, and screen the target materials with the best composition and performance. The traditional “trial and error” mode has been transformed into a new mode of system optimization in materials exploration. At the same time, high-throughput preparation experiments can complement virtual experiments such as material computing and machine learning to verify the calculation results, and provide an abundant experimental database for data mining and application. This paper reviews the parallel synthesis methods of micro-nano powder and their progress, which provide new ideas and efficient synthesis routes for the functional materials scientists to accelerate the experimental process. The mentioned high-throughput experimental methods have been applied to the rapid discovery, optimization and performance improvement of new materials, such as catalysts, phosphors, infrared irradiative materials, and so on, which is expected to expand the application area and scale, highlighting its advancement and value.