Amorphous carbonas one of disordered carbon materials usually exhibits different mechanical, electrical, optical and thermal properties from crystalline carbon materials. Exploring high-performance amorphous carbon materials is always a research hotspot. In this paper, a high-strength amorphous carbon composed of onion-like structural elements was reported. This kind of amorphous carbon was obtained via treating carbon black at high temperature and high pressure (i.e., 1 700-2 000 ℃ and 6 GPa), which shows excellent mechanical properties. The nano indentation hardness, indentation elastic recovery, uniaxial compressive and flexural strength of the sample with best performance are 5.1 GPa, 80.1%, 956.4 MPa and 216.0 MPa, respectively. The compressive and flexural strengths of the amorphous carbon are 5.6 times and 2.8 times greater than those of Toyo Tanso ISO-68 graphite, respectively. This kind of amorphous carbon also has a good conductivity, and its room-temperature resistivity can be as low as 75.7 μΩ·m. This high-strength conductive amorphous carbon can be widely used as electrode and mold materials.

Two-dimensional transition metal chalcogenides have diverse material species and physical properties, and their lateral and vertical heterostructures provide more freedoms to expand their applications in electronic and optoelectronic devices. Interfacial control, such as the interface structure, coupling strength and epitaxial size, is crucial for the heterostructure design. This paper was to develop an effective method to precisely control the in-plane heteroepitaxial interface structure, and reported the effective synthesis of the antiparallel MoS2-WS2 in-plane heterostructure. Based on the multi-scale characterizations, the lattice of the macroscopic antiparallel heterojunction is arranged parallelly in a microscopic scale, resulting in the seamlessly stitching of MoS2 and WS2 domains at their interface. MoS2-WS2 in-plane heterojunctions with the interface structures was further synthesized, paving an effective way for the precise interfacial control of two-dimensional material heteroepitaxy.

As a carbon resource with abundant nitrogen, polyacrylonitrile (PAN) has been used for the key raw materials to produce carbon materials. However, the direct carbonization will lead to the cementation of PAN particles, which is adverse to the subsequent activation. In this work, a hybrid porous carbon (HPC) was synthesized via dry ball-milling of thermal-reduced graphene and polyacrylonitrile, and subsequent stabilization and KOH activation. The effect of the ratio of graphene and polyacrylonitrile, along with activation treatment on the properties of hybrid porous carbon are systematically studied. The results demonstrate that the existence of graphene nanosheets enable the fast dissipation of heat produced in ball-milling process and avoid the cementation of PAN particles, while PAN particles act as spacers to prevent graphene restacking. The as-obtained polyacrylonitrile/graphene precursor is a loose powder, which favors the dispersion of activation agents within the precursor and results in a more homogeneous and effective activation. Meanwhile, graphene works as a 3D micro-current collector, thus providing a conductive network for convenient charge transfer in HPC. Based on the electrochemical characterization in either water or a non-aqueous electrolyte, HPC exhibits a superior capacitive behavior because of its well-developed porosity, large specific surface area, excellent electrical conductivity as well as nitrogen/oxygen heteroatom induced pseudo-capacitance. Particularly, HPC-4 offers a high energy density of 30.38 W?偸h/kg at a power density of 337.5 W/kg in TEABF4/EC-DMC electrolyte. This work provides an easy-to-operate and efficient synthesis strategy for developing porous carbon electrode towards supercapacitors with high power and energy density.

Flexible and wearable sensors have attracted wide attention for their potential applications in human health monitoring, telemedicine and human-machine interface systems. Graphene has some advantages of good electrical conductivity, high flexibility, light weight, high thermal stability and potential mass production, as one of promising ideal candidate materials for flexible and wearable sensors. Consequently, recent efforts are made on the controlled fabrication of graphene materials with designed structures towards application in the next generation of flexible electronics. This review represented recent developmenton the preparation of graphene and their applications in flexible and wearable sensors. The preparation methods of graphene materials with different morphologies were introduced. The preparation strategies, working mechanisms, performance and applications of graphene-based flexible sensors, including strain sensors, pressure sensors, temperature sensors, humidity sensors and other sensors were discussed. The multi-mode graphene-based flexible sensors were introduced. It is indicated that graphene-based flexible sensors possess superior sensitivity and stability, having a great potential for applications in temperature monitoring, speech recognition, pulse, motion and respiratory detection. In addition, the existing challenges and the future development of flexible graphene-based sensors were also given.

As a carbon nanomaterial, graphene exhibits the superior mechanical, electrical and thermal properties, indicating an enormous application potential in the field of flexible electronic devices. In flexible devices, interfacial mechanical performance between graphene and flexible substrate can determine the reliability of devices performance. This review represented recent development on the interfacial mechanical performance of graphene/flexible substrate, i.e., experimental technology (by Raman spectroscopy, atomic force microscopy and pressurized blister test) and theoretical calculation model (shear-lag theory, nonlinear shear-lag analysis, bilinear cohesive law and two-dimensional nonlinear shear-lag mode). In addition, the relevant applications and difficulties of flexible graphene devices based on its interfacial mechanical research were also introduced. Finally, the future research and application were prospected.

Graphene quantum dot is one of the most important derivants of graphene. With the quantum size effect, graphene quantum dots show a distinct semiconductive nature, compared with intrinsic graphene. Graphene quantum dots have a high application value in fluorescent anti-counterfeiting materials, biological imaging, tumor diagnosis and treatment, and photo/electrocatalysis due to their superior photoluminescence properties, high stability, low biotoxicity, modulated interface structure. This review represented the photoluminescence properties of graphene quantum dots. The bandgap structure of graphene quantum dots, which is related to the important basic physical properties of the material in various applications was summarized. This review can provide a reference for the future studies on the photoluminescence performance modulation and mechanism of graphene quantum dots.

As one of carbon nanomaterials, carbon dots have attracted widespread attention due to their ultra-small size, abundant surface functional groups, good chemical stability, and superior optoelectronic properties. In this review, the structures, classifications, characteristics, and preparation methods of carbon dots were introduced. Recent research studies on carbon dots as various components or additives in dye-sensitized solar cells were represented. The challenges of controllable synthesis, structure-property relationship, and performance optimization of carbon dots were analyzed. In addition, the development directions of large-scale controllable preparation for carbon dots and their application in dye-sensitized solar cells were proposed.

Hard carbon (HC) materials are considered as promising anode materials for sodium-ion batteries (SIBs) due to their advantages of high capacity, low working potential, and low cost. The most important feature of HC materials is a rich microcrystalline structure that is conducive to the sorption and insertion/extraction of sodium ions, which in turn enables HC materials to exhibit a superior sodium ion storage performance. However, HC materials have some problems such as low initial Coulombic efficiency (ICE), insufficient long-cycle stability, and poor rate performance in the application. A functional design can be an effective strategy to improve these problems of HC. This review mainly summarized recent studies on the modification of HC anode for SIBs, and provided the related information on some typical optimization strategies and the latest research progress in the functional design of HC anodes. The advantages and disadvantages of functional design were also discussed, providing a theoretical basis and technical support for guiding the commercial application of HC anodes for SIBs.

In the application of the third-generation semiconductors, the power density of electronic devices increases and the size is miniaturization. A problem of high temperature becomes more prominent. Diamond is one of the optimum heat dissipation materials because of its ultra-high thermal conductivity and stable properties. In this review, the design principle and development process of different microwave plasma chemical vapor deposition equipment were introduced. Recent developments on different thermal applications of single crystal, polycrystalline and nanocrystal diamond were represented. Some challenges in the industrialization process combined with the 3rd-generation-semiconductors and the development direction of "larger, purer and faster" were summarized. In addition, the future research direction of diamond heat dissipation application was also prospected.

Spinel LiMn2O4 cathode materials suffer a serious capacity decay and a poor cycle stability during the charge-discharge process due to the Jahn-Teller effect and Mn dissolution. A cathode material of truncated octahedral single crystal LiFe0.12Mn1.88O4 with {111}, {100} and {110} surfaces was prepared by a solid-state combustion method and element doping and single crystal morphology controlling strategies. The results show that the crystal structure of spinel LiMn2O4 is not changed by Fe doping, the Jahn-Teller effect is effectively inhibited, the crystallinity and the selective growth of {400} and {440} diffraction peak crystal planes are promoted, and the material has superior rate performance and capacity retention. The initial discharge specific capacities at 1 C and 5 C at 25 ℃ are 105.2 mA·h/g and 92.4 mA·h/g, and the capacity retentions after 1 000 cycles are 71.1% and 75.2%, respectively. Moreover, the capacity retention reaches 88.4% after 1 000 cycles at 10 C. The initial discharge capacity of the material is 108.6 mA·h/g at 55 ℃ and 1 C, and the capacity retention rate is 79.1% after 150 cycles, and the capacity retention rate is 79.1% after 150 cycles. By using cyclic voltammetry and electrochemical impedance spectroscopy, we found that the Fe-doped sample has superior circulation reversibility and large Li+ diffusion coefficient. The Fe-doped material of truncated octahedral LiMn2O4 inhibits the Jahn-Teller effect, and slows down the Mn dissolution, thus stabilizing the crystal structure, increasing the Li+ migration channel, and improving the electrochemical rate performance and long cycle life.

The preparation of silicon anode materials via reduction of silicate minerals can improve the electrochemical properties and reduce the production cost. In this paper, silicon-carbon composites were prepared by a simple evaporation solvent method with natural halloysite aluminothermic reductive product as a raw material and asphalt as a carbon source. The results show that silicon exists in the form of nanotubes with a diameter of approximately 30 nm. The carbon layer is uniformly coated on the silicon nanotubes, which increases the diameter of the silicon carbon composite. The thickness of the carbon layer is approximately 7 nm. The carbon exists in an amorphous structure, and the carbon coating leads to the decrease of the specific surface area. According to the results of electrochemical tests, the optimum electrochemical performance of silicon-carbon composites can be obtained at a mass fraction of coated carbon of 15%, i.e., the first charge and discharge capacities of 1 387.8 mA瘙
簚h/g and 1 615.7 mA瘙
簚h/g, respectively, and the first coulomb efficiency of 85.9%. The silicon-carbon composites maintain the first charge discharge efficiency of silicon nanotubes, and greatly improve the cycle performance. Compared with the 200 cycles capacity retention rate of silicon nanotubes of 38%, the 200 cycles capacity retention rate of silicon-carbon composites coated with a carbon content of 15% is increased by 45.8%. The specific capacity of silicon-carbon composites coated with a carbon content of 15% is 1 065.6 mA瘙
簚h/g after 500 cycles. The capacity retention rate is 76.8%.

Composite polymer electrolyte is one of the most promising electrolyte candidates for future solid state lithium batteries, but inorganic fillers used are prone to an agglomeration, thus being difficult to form a continuous ion transport pathway. Flexible SiO2 nanofiber porous membranes were fabricated by an electrospinning technique and a heating treatment process. The samples were characterized by scanning electron microscope, fourier transform infrared spectrometer, X-ray diffractometer, and thermogravimetry analyzer. The effects of TEOS proportion and polymer concentration in electrospinning precursor on the morphology and flexibility of the nanofiber porous membranes were investigated. Moreover, the electrochemical properties of PEO based composite polymer electrolyte (CPE-SiO2) were analyzed. The ionic conductivity of this composite electrolyte can reach 2.52×10-5 S/cm at 30 ℃. LiFePO4|CPE-SiO2|Li can be steadily charged/discharged for 50 times at 1 C rate and 60 ℃. Li|CPE-SiO2|Li symmetric cell can keep a stable overpotential profile for 300 h with a low hysteresis at 60 ℃. This work provides an effective approach for the commercialization of next generation high-performance all-solid-state batteries.

Anthracite has a great application potential in energy storage because of its low cost, but the reversible capacity of raw anthracite as an anode material for the sodium-ion battery is rather low. In this paper, anthracite was pyrolyzed at different temperatures. The results show that the reversible capacity of anthracite pyrolyzed at 1 300 ℃ (A-1300) is 307 mA·h/g at 20 mA/g, which is the maximum value among the pyrolyzed anthracites. However, the reversible capacity of A-1300 at 500 mA/g is only 105 mA·h/g, exhibiting an inferior rate performance. The two-step strategy via hydrogenation and pyrolysis can decrease the pyrolyzed temperature and improve the rate performance. Hydrogenated anthracite turns into an easy-graphitized precursor. The reversible capacity of hydrogenated anthracite pyrolyzed at 900 ℃ (H300-3-900) can retain 113 mA·h/g at 500 mA/g after 500 cycles, exhibiting a superior rate performance and an easier commercial production at a lower temperature.

The manufacture of flexible, miniature, large-area and low-cost energy storge units has attracted much attention with a rapid development of flexible electronic devices. In this paper, NiCo2S4/g-C3N4 nanocomposite material was prepared via a one-step solvothermal process with nickel and cobalt nitrate hexahydrate as raw materials, thiourea as a vulcanizing agent and pyrolysis g-C3N4. The interdigital electrode of NiCo2S4/g-C3N4 was created via mask printing on a polyethylene glycol terephthalate flexible substrate with the well-prepared ink. The flexible interdigital supercapacitor was obtained by coating a layer of gel electrolyte. Based on the structure and electrochemical performance characterizations, NiCo2S4 nanoparticles dispersedly grow on g-C3N4 nanoplates, thus improving the charge transfer and accommodating the volume expansion of NiCo2S4 during charge-discharge cycles. The area specific capacitance of the nanocomposite electrode is 9.1 F/cm2 at a current density of 10 mA/cm2. The assembled supercapacitor can operate at -0.2-0.6 V and remainsstable at a scanning rate of 500 mV/s, revealing a good rate performance. The area specific capacitance of the device is 5.7 mF/cm2 at a scanning rate of 20 mV/s, and the energy density is 0.56 mW?偸h/cm3 at a power density of 17.5 mW/cm3.

High-conductivity titanium nitride nanowire can be used as a growth substrate of polyaniline to reduce the charge transfer resistance of the electrode material and improve the supercapacitor behavior of polyaniline. A polyaniline/titanium nitride nanowire (PANI/TiN) was synthesized as a supercapacitor electrode material via seed-assisted hydrothermal process and high-temperature calcinations with flexible carbon fiber as a substrate. PANI/TiN nanowires have a highly ordered coaxial core-shell nanowire structure, and the nanowires split each other to favor the ion diffusion and electron transportation and improve the energy storage performance. PANI/TiN exhibits a higher specific capacitance of 403 F/g at 1 A/g and a higher capacitance retention of 53.4% when the current density increases from 0.5 A/g to 10.0 A/g. The capacitance retention rate of PANI/TiN is 79.1% after 1 000 cycles of charging and discharging at 5 A/g. Compared with PANI, PANI/TiN has the improved electrochemical energy storage properties. The flexible all-solid-state symmetric supercapacitor (i.e., PANI/TiN supercapacitor) was assembled by using PANI/TiN as an electrode. PANI/TiN//PANI/TiN supercapacitor has the specific capacitance of 100.2 F/g at 1 A/g, and there is little attenuation of the specific capacitance after bending at different angles. PANI/TiN//PANI/TiN supercapacitor can obtain an energy density of 50.1 W?偸h/kg at a power density of 500 W/kg. Red light emitting diode (a rated voltage of 1.8 V) can be lighted up by one unit of the supercapacitor, indicating a promising potential application for energy storage.

As one of microwave absorbing materials, SiC nanowires have a good microwave absorbing property, a wide microwave absorbing bandwidth and a low density. However, the poor impedance matching condition and low conductivity of SiC affect the improvement of its microwave absorbing property. To adjust the electronic structure of SiC and improve its electromagnetic properties, La3+ doped SiC nanowires were synthesized via carbothermal reduction at 1 600 ℃ with silicon powder, activated carbon and La2O3 powder as raw materials. The results show that doping La3+ can increase the aspect ratio and stacking fault density of SiC nanowires, and enhance their ability to form three-dimensional network structure and interface polarization, and improve their dielectric properties. At 2-18 GHz, the real part of permittivity increases from 3.08-13.48 (x = 0) to 3.33-19.75 (x = 1.0%), and the imaginary part of permittivity increases from 3.45-6.98 (x = 0) to 5.03-11.56 (x = 1.0%). Also, La3+ doping improves the conductivity of SiC nanowires and enhances its conductivity loss. SiC nanowires doped with 1.0% La3+ achieve a minimum reflection loss (RL) of -31.29 dB with the thickness of 2.0 mm and the effective absorption bandwidth with RL<-10 dB of 7.18 GHz due to the simultaneous enhancement of interface polarization and conductivity loss of SiC nanowires. The electronic structures of SiC nanowires and La3+ doped SiC nanowires were analyzed via the first-principle calculations. The results show that the band gap of SiC nanowires decreases after La3+ doping, verifying the enhancement of their conductivity. La3+ doping can increase the stacking fault density of SiC nanowires and solve a problem that the stacking fault density decreases. The results of this study can provide an idea for the synthesis of SiC nanowires with a high electromagnetic absorbing capability.

Metal-supported solid oxide fuel cells have promising applications. However, there is no the corresponding cost-effective preparation technology. Yttria stabilized zirconia (YSZ) electrolyte of solid oxide fuel cell was fabricated on a meatal substrate via high-efficiency and low-cost atmospheric plasma spraying (APS). The relationship between depositional particle morphology and coating structure under heating matrix conditions was investigated. The mechanical properties of electrolyte and cell out performance were evaluated. The results indicate that YSZ deposition particles on the heated substrate are fully spread. However, some microcracks appear in the splats, leading to some vertical cracks and interlamellar unbonded-interfaces inside the coating, the porosity is 7.16%, and nanoindentation hardness and elastic modulus of YSZ electrolyte are (13±1.04) GPa and (188.5±2.59) GPa, respectively. The maximum open voltage of cell with YSZ electrolyte deposited by APS is 0.97 V, thus improving the density. Nevertheless, the cell out performance is quite considerable with a peak power density of 850 mW/cm2 at 900 ℃. After the optimization of equipment iteration or combined with the post-treatment process, APS can be used to obtain alarge-scale and low-cost preparation of dense YSZ electrolytes.

Cu2ZnSnS4 has good photocatalytic application prospects due to its high absorption coefficient in a visible light range and high carrier mobility, but the limited photocatalytic activity and catalytic stability restricts its practical applications. Cu2ZnSnS4 nanomaterial was prepared by a hydrothermal method with zinc chloride, tin chloride, copper chloride and thiourea as precursors, and PEG400 and OP10 as surfactants. The microstructure of the as-prepared Cu2ZnSnS4 nanomaterial was characterized and the influence of surfactant on the optical band gap and the photocatalytic degradation performance of the samples was determined by X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy, respectively. The results show that three kinds of Cu2ZnSnS4 materials prepared all have a kesterite micro-phase, and the addition of PEG400 and OP10 into the precursor results in the variation of the microstructure, stoichiometric ratio and optical band gap of the materials, consequently determining their photocatalytic properties. After methylene blue degradation for 50 min, Cu2ZnSnS4 nano-powder synthesized with PEG400 has an optimum photocatalytic degradation rate (i.e., 95.7%). It is indicated that the photocatalytic activity and stability of Cu2ZnSnS4 nanomaterials can be improved by reducing the optical bandgap and enhancing the crystallinity, thus paving a promising approach to improve its photocatalytic performance.

The existing NOx post-treatment techniques of diesel vehicle exhaust have a poor performance during the cold start, passive NOx adsorbent (PNA) is thus proposed. In this paper, Pd/ZSM-5 PNA was obtained by loading 1% Pd onto ZSM-5 zeolite in Si/Al ratio of 11.5 via incipient wetness impregnation and ion exchange, respectively. The effect of reaction atmosphere (with or without O2 and H2O) on the adsorbed-released NOx performance of PNA with two Pd loading methods was investigated. The mechanism of the factors affecting the structure properties, Pd species state and acid properties of Pd/ZSM-5 was analyzed by X-ray diffraction, N2 adsorption-desorption isotherm, transmission tlectron microscopy, in-situ diffuse reflectance infrared Fourier transform spectroscopy and NH3-temperature programmed desorption, respectively. The O2 effect in the pretreatment atmosphere was further evaluated. The results show that there are more NO active adsorption sites with O2 in pretreatment and reaction atmosphere during incipient wetness impregnation, thus improving the NO adsorption capacity of Pd/ZSM-5. In addition, O2 promotes the release of NOx at a lower temperature (~200 ℃), and an incipient wetness impregnation method reduces the release temperature to 430 ℃, which is conducive to the material regeneration. H2O inhibits NO adsorption, but promotes NOx release capacity at a higher temperature. This work can provide a reference for the design of high-performance Pd/zeolites. High adsorption-release capacity is the important prerequisite for the development of high-performance PNA.

Mordenite is highly active for the carbonylation of dimethyl ether reaction, and the regulation of its acid sites is an effective way to improve its catalytic performance. In this paper, a series of mordenite was subjected to the post-treatment of oxalic acid solution. The changes in the structure and acid sites were characterized by X-ray diffraction, N2 adsorption-desorption, scanning electron microscopy, NH3-temperature-programmed desorption and Py-infrared spectroscopy, respectively. The results show that the overall relative crystallinity and crystal phase of mordenite remain stable. However, the acid wash post-treatment can effectively remove parts of the acid sites through "etching" or complexation, especially those located in the twelve-membered ring channels. Meanwhile, it can create a certain amount of mesopores inside the particles, leading to an increase of the mesopore volume. The catalytic test results of dimethyl ether carbonylation reaction indicate that the sample treated with a suitable concentration of oxalic acid solution can effectively improve the dimethyl ether carbonylation activity. The dimethyl ether conversion significantly increases, despite the methyl acetate selectivity only slightly decreases. However, parts of the active sites responsible for the carbonylation reaction are removed when treated with high-concentration oxalic acid solution, resulting in a decrease in the catalytic activity. This research provides a simple and effective method for the regulation of the acid sites in mordenite and the improvement of its dimethyl ether carbonylation activity.

The osteogenic activity and mechanical properties of the bone repair scaffold are important for its clinical application. Mg-M/HT porous composite scaffold was prepared with hardystonite (Ca2ZnSi2O7, HT) with good mechanical properties as a matrix and Mg-doped biodegradable mesoporous bioactive glass (MBG) as a coating. The effect of Mg doping on the microstructure and osteogenic activity of the M/HT composite scaffold was investigated. The microstructures of the composite scaffolds were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR). The osteogenic activity of the scaffolds was investigated with human bone marrow mesenchymal stem cells (hBMSCs). The results show that Mg doping can reduce the mesoporous order of MBG to a certain extent, but Mg-M/HT composite scaffold still has a uniform and ordered pore structure. Compared with M/HT scaffold, Mg-M/HT scaffold has higher intracellular focal adhesion proteins and integrins, as well as alkaline phosphatase, calcium nodules and osteocalcin expression, indicating that Mg doping can promote the osteoblast activity of M/HT scaffold. Mg-M/HT scaffold has a potential application in the field of bone tissue repair.

To reveal the mechanism of the inert gehlenite (C2AS) phase in sulfoaluminate cement clinker at a low Al2O3/SiO2 ratio, a series of clinkers were prepared at different calcination temperatures and holding time as well as a fixed Al2O3/SiO2 ratio of 2. The evolution of C2AS was investigated by X-ray diffraction combined with the Rietveld method and thermogravimetry-differential scanning calorimetry. The results show that C2AS is produced by the reaction of CaO, SiO2 and Al2O3 at 950-1 200 ℃. C2AS is mainly produced by the reaction of CA and CaO decomposed from C4A3$ with the residual SiO2 when the temperature exceeds 1 200 ℃. It is indicated that the kinetics of the C2AS formation above 1 200 ℃ is mainly controlled by the diffusion of Ca2+, and the activation energy of the reaction is (305±20) kJ/mol. This study provides a a guidance for the use of low-grade bauxite in the calcination of sulfoaluminate cement clinker.

Silicon dioxide (SiO2) membrane has attracted much attention in the field of separation and purification due to its high-temperature resistance and adjustable pore size. However, the amorphous structure on the surface leads to the mutual restriction of permeability and selectivity, which affects the results of separation. A SiO2@ZIF-8 composite membrane was prepared with SiO2 membrane as abase membrane and modified with metal organic framework material (ZIF-8). The effects of synthesis condition of ZIF-8, addition amount of ZIF-8 and temperature of raw material solution on the dehydration inaqueous ethanol solution mixture under pervaporation conditions were investigated. The results show that the regular channel structure in ZIF-8 can provide additional channels for water molecule transport, the water content on the permeate side of the composite membrane is 99.5 %, the permeate flux increasesto 9.6 kg/(m2·h) and the separation factor is 1 973. A relationship between membrane permeation flux and temperature follows the Arrhenius equation. The apparent activation energy of water molecules in the composite membrane is higher, and the water flux increases faster with the increase of temperature, indicating a better separation effect. SiO2@ZIF-8 composite membrane can effectively improve the defects of amorphous network structure of silica film, which has a broad application prospect in the dehydration of organic solvent by pervaporation.

Membrane separation technology has attracted extensive attention in the fields of seawater desalination and wastewater treatment due to its unique advantages, such as low energy consumption, high separation efficiency, and no phase transition. In this paper, graphene oxide (GO) and dopamine modified halloysite (D-HNTs) composite films were prepared via vacuum filtration with commercial nylon microporous film as a base film. The optimum ratio of film formation was obtained via examining a pure water flux, a hydrophilic performance, and a retention performance of composite films. The application of composite film in the field of liquid filtration was presented. The results show that the interlayer transport channel of composite film becomes greater with increasing the proportion of D-HNTs in composite film. Among them, at a mass ratio of GO:D-HNTs of 6:4, GO film formation is complete, the corresponding rejection rate of methylblue is 97.28%, and the pure water flux reaches 123.14 L/(m2·h) under a transmembrane pressure of 0.1 MPa. In addition, a pollution experiment was also carried out for 3 cycles with bovine serum albumin as a pollutant. The water flux recovery rate of composite film can reach >96%, indicating the superior anti-fouling performance.

To investigate the effect of CO gas partial pressure on the morphology and quantity of one-dimensional SiC catalyzed by copper, one-dimensional silicon carbide (SiC) with different morphologies was synthesized by a catalytic reaction method with silicon powder and phenolic resin as raw materials, and copper tartrate as a catalyst precursor. The samples were characterized by X-ray diffraction, field emission-scanning electron microscopy and transmission electron microscopy. The effects of catalyst, atmosphere and temperature on the morphology of SiC were investigated. The results indicate that the worm-like one-dimensional SiC is formed without a catalyst at 1 400 ℃. The Cu-catalyzed one-dimensional SiC with a chain-bead structure was synthesized under an argon atmosphere at 1 200 ℃, and the Cu-catalyzed one-dimensional SiC with a core-shell structures was synthesized under a CO atmosphere at 1 200 ℃. The growth mechanism of worm-like SiC is the reaction of gaseous phase CO and liquid phase Si to form a solid-phase SiC (i.e., V-L-S mechanism), and the growth mechanism of SiC with a chain-bead structure and a core-shell structure is the direct reaction of vapor phase SiO and CO to form solid-phase SiC (i.e., V-S mechanism). The results of this work can provide a theoretical basis for the in-situ formation of one-dimensional SiC ceramic reinforced phases with different morphologies in carbon-containing refractories.

It is of great practical significance to develop thermal insulation materials with integrated load bearing and thermal insulation for energy saving and emission reduction in high-temperature engineering. In this work, SiO2f/SiO2 composites were prepared by a precursor impregnation heat-treatment method with quartz fiber needled felt as a reinforcement and silica sol as a precursor. The effect of heat-treatment temperature on the density, porosity, mechanical properties and thermal properties of SiO2f/SiO2 composites was investigated. The composition and microstructure of the composites were characterized by X-ray diffraction and scanning electron microscopy. The coefficient of thermal expansion and thermal conductivity of composites were measured by a push rod method and a transient hot-wire method. The results indicate that the apparent porosity and mechanical strength firstly increase and then decrease with the increase of heat-treatment temperature. The sample after heat-treatment at 450 ℃ has the optimum overall performance (i.e., the flexural strength of 23.5 MPa, and the compressive strength of 61.9 MPa). The fracture mechanism is a ductile fracture. At 300-700 ℃, the thermal expansion coefficient of the sample is 0.564×10-6/℃. The thermal conductivity of the samples decreases with the increase of temperature, and it is as low as 0.096 W/m·K at 700℃. The SiO2f/SiO2 composite prepared has some advantages in the integrated application of load bearing and thermal insulation, and meets the harsh requirements of hot pressing and sintering, non-ferrous metallurgy and other industries.

Reducing the operational temperature for high-temperature solid oxide fuel cell (SOFC) is of great significance to improve the stability of materials, increase the operation life of the system and reduce the fabrication and operation cost of the cell. This aspect has therefore attracted recent research attention. So far, different research strategies were proposed to reduce the operational temperature. This review represented recent research progress on the composite electrolyte in low-temperature solid oxide fuel cell (LT-SOFC). The carbonate materials as the second phase for composite preparation of molten carbonate-like SOFCs and the transition metal oxide materials as the second phase for composite preparation were introduced. The single-component fuel cell for eliminating the interface resistance between electrode and electrolyte and improving the fuel cell performance and the stability of the peroxide composite electrolyte was elaborated. The semiconductor composites to enhance LT-SOFC's electrochemical performance were described. In addition, this review also represented the preparation of novel nanocomposites to further enhance the electrolyte ionic conductivity and the interfacial compatibility, and the explorations of the electrochemical performance of LT-SOFC with respect to the effect of novel electrode materials.

The photocatalytic reduction of CO2 is a green, environmental-friendly energy conversion way to realize the carbon cycle of ecosystem. This method can effectively convert greenhouse gases into renewable fuels, thus alleviating energy crisis and global warming problems. This review represented recent research work on the semiconductor composites in photocatalytic reduction of CO2 and the reaction conditions and photocatalytic mechanism of photocatalytic reduction of CO2. Based on the previous reports, the main types of semiconductor composites of photocatalytic reduction of CO2 were summarized, i.e., pure semiconductor photocatalysts, metal and nonmetal doped semiconductor photocatalysts, composite semiconductor photocatalysts, and carbon-based semiconductor photocatalysts. In addition, the advantages and disadvantages of various photocatalytic materials and some factors affecting photocatalytic activities were also analyzed. The future research aspects on the catalytic reduction of CO2 by semiconductor composites were prospected.

With the rapid development of absorbing materials due to the demand for stealth technology in the military and national defense field and the increasingly serious electromagnetic pollution in life, various types of absorbing materials emerge. Compared with the conventional carbonaceous absorbing materials, biomass-derived carbonaceous materials improve the absorbing performance due to their advantages like light weight, low cost and sustainability. This review briefly represented the synthesis methods of biomass carbon materials, systematically introduced the application of edible and non-edible biomass derived materials in the preparation of carbonaceous composite absorbing materials, and described recent work on the biomass-derived carbonaceous materials. Recent research progress on the composite materials in the field of wave absorption was given. The differences in the microstructure and microwave absorption properties of different biomass-derived carbonaceous composites were mainly analyzed, and the microwave absorption mechanism of different biomass-derived carbonaceous composites was summarized. The current challenge and the directional perspective of biomass-derived carbonaceous composites absorbing materials with efficient microwave absorption properties were discussed. This review provides a comprehensive theoretical and applied knowledge background for the investigation of biomass-derived absorbing materials, which can promote the development and application of biomass-derived carbon-based composite absorbing materials.