[1] T YIN X, P LV, J LI et al. Nanostructured tungsten trioxide prepared at various growth temperatures for sensing applications. Journal of Alloys and Compounds, 825, 154105(2020).

[2] D NANDIYANTO A B, R OKTIANI, R RAGADHITA et al. Amorphous content on the photocatalytic performance of micrometer-sized tungsten trioxide particles. Arabian Journal of Chemistry, 13, 2912-2924(2020).

[3] X HE, Y WANG X, N SUN B et al. Synthesis of three- dimensional hierarchical furball-like tungsten trioxide microspheres for high performance supercapacitor electrodes. RSC Advances, 10, 13437-13441(2020).

[4] J HAI G, F HUANG J, Y CAO L et al. Influence of oxygen deficiency on the synthesis of tungsten oxide and the photocatalytic activity for the removal of organic dye. Journal of Alloys and Compounds, 690, 239-248(2017).

[5] F LIU X, H ZHOU, Z PEI S et al. Oxygen-deficient WO₃-_x nanoplate array film photoanode for efficient photoelectrocatalytic water decontamination. Chemical Engineering Journal, 381, 122740(2020).

[7] Q QUAN H, F GAO Y, Z WANG W. Tungsten oxide-based visible light-driven photocatalysts: crystal and electronic structures and strategies for photocatalytic efficiency enhancement. Inorganic Chemistry Frontiers, 7, 817-838(2020).

[8] K PERSSON. Materials project. https://materialsproject.org/

[9] K DEB S. Opportunities and challenges in science and technology of WO₃ for electrochromic and related applications. Solar Energy Materials and Solar Cells, 92, 245-258(2008).

[10] Y DING, S YANG I, Q LI Z et al. Nanoporous TiO₂ spheres with tailored textural properties: controllable synthesis, formation mechanism, and photochemical applications. Progress in Materials Science, 109, 100620(2020).

[11] Y DONG P, H HOU G, U XI X et al. WO₃-based photocatalysts: morphology control, activity enhancement and multifunctional applications. Environmental Science-Nano, 4, 539-557(2017).

[12] F HAN L, L CHEN J, H ZHANG Y et al. Facile synthesis of hierarchical carpet-like WO₃ microflowers for high NO₂ gas sensing performance. Materials Letters, 210, 8-11(2018).

[13] S LI Y, L TANG Z, Y ZHANG J et al. Fabrication of vertical orthorhombic/hexagonal tungsten oxide phase junction with high photocatalytic performance. Applied Catalysis B-Environmental, 207, 207-217(2017).

[14] M HUNGE Y, A YADAV A, A MAHADIK M et al. A highly efficient visible-light responsive sprayed WO₃/FTO photoanode for photoelectrocatalytic degradation of brilliant blue. Journal of the Taiwan Institute of Chemical Engineers, 85, 273-281(2018).

[15] M KARADENIZ S, D TATAR, M ERTUGRUL et al. Structural, optical and electrochromic properties of WO₃ thin films prepared by chemical spray pyrolysis versus spin coating technique. Spectroscopy and Spectral Analysis, 38, 2982-2988(2018).

[16] I INAMDAR A, S CHAVAN H, A AHMED A et al. Nanograin tungsten oxide with excess oxygen as a highly reversible anode material for high-performance Li-ion batteries. Materials Letters, 215, 233-237(2018).

[17] P SHENG J, L ZHANG, L DENG et al. Fabrication of dopamine enveloped WO₃-_x quantum dots as single-NIR laser activated photonic nanodrug for synergistic photothermal/photodynamic therapy against cancer. Chemical Engineering Journal, 383, 123071(2020).

[18] Y ZHAO L, L XI X, S LIU Y et al. Growth mechanism and visible-light-driven photocatalysis of organic solvent dependent WO₃ and nonstoichiometric WO₃-_x nanostructures. Journal of the Taiwan Institute of Chemical Engineers, 115, 339-347(2020).

[19] Y ZHAO L, L XI X, S LIU Y et al. Facile synthesis of WO₃ micro/nanostructures by paper-assisted calcination for visible- light-driven photocatalysis. Chemical Physics, 528, 110515(2020).

[20] S FAN Y, L XI X, S LIU Y et al. Growth mechanism of immobilized WO₃ nanostructures in different solvents and their visible-light photocatalytic performance. Journal of Physics and Chemistry of Solids, 140, 109380(2020).

[21] K MANTHIRAM, P ALIVISATOS A. Tunable localized surface plasmon resonances in tungsten oxide nanocrystals. Journal of the American Chemical Society, 134, 3995-3998(2012).

[22] Y KIMURA, K IBANO, K UEHATA et al. Improved hydrogen gas sensing performance of WO₃ films with fibrous nanostructured surface. Applied Surface Science, 532, 147274(2020).

[23] D LI, Q HUANG W, Z XIE et al. Mechanism of enhanced photocatalytic activities on tungsten trioxide doped with sulfur: dopant-type effects. Modern Physics Letters B, 30, 1650340(2016).

[24] X QIN Y, M LIU, H YE Z. A DFT study on WO₃ nanowires with different orientations for NO₂ sensing application. Journal of Molecular Structure, 1076, 546-553(2014).

[25] J CHEN Z, X CAO J, W YANG L et al. The unique photocatalysis properties of a 2D vertical MoO₂ /WO₂ heterostructure: a first- principles study. Journal of Physics D-Applied Physics, 51, 265106(2018).

[27] Q JIA Q, M JI H, X BAI. Selective sensing property of triclinic WO₃ nanosheets towards ultra-low concentration of acetone. Journal of Materials Science-Materials in Electronics, 30, 7824-7833(2019).

[28] L MA Y, B FENG, Y LANG J et al. Synthesis of semimetallic tungsten trioxide for infrared light photoelectrocatalytic water splitting. Journal of Physical Chemistry C, 123, 25833-25843(2019).

[30] M DIRAC P A. The Principles of Quantum Mechanics, 1-22(1958).

[32] M BORN, K HUANG. Dynamical Theory of Crystal Lattices, 104-113(1958).

[33] C SLATER J. Magnetic effects and the Hartree-Fock equation. Physical Review, 82, 538-541(1951).

[36] W KOCH, C HOLTHAUSEN M. A chemist's guide to density functional theory. Zeitschrift für Physik B Condensed Matter, 78, 317-323(2001).

[37] W KOHN, J SHAM L. Self-consistent equations including exchange and correlation effects. Physical Review, 140, 1133-1138(1965).

[38] H THOMAS. The calculation of atomic fields. Proceedings of the Cambridge Philosophical Society, 23, 542-548(1927).

[39] W KOHN. Nobel lecture: electronic structure of matter-wave functions and density functionals. Reviews of Modern Physics, 71, 1253-1266(1999).

[40] E FERMI. Un metodo statistico per la determinazione di alcune Priorieta dell atome. Rend. Accad. Naz. Lincei, 6, 602(1927).

[41] M DIRAC P A. Note on exchange phenomena in the thomas-fermi atom. Proceedings of the Cambridge Philosophical Royal Society, 26, 376(1930).

[42] C SLATER J. A simplification of the hartree-fock method. Self-Consistent Fields in Atoms, 81, 215-230(1975).

[43] P PERDEW J, A CHEVARY J, H VOSKO S et al. Atoms, molecules, solids, and surfaces-applications of the generalized gradient approximation for exchange and correlation. Physical Review B, 46, 6671-6687(1992).

[45] D VANDERBILT. Soft self-consistent pseudopotentials in a generalized eigenvalue formalism. Physical Review B, 41, 7892-7895(1990).

[46] E BLÖCHL P. Projector augmented-wave method. Physical Review B Condens Matter, 50, 17953-17959(1994).

[47] R HAMANN D, M SCHLÜTER, C CHIANG. Norm-conserving pseudopotentials. Physical Review Letters, 43, 1494-1497(1979).

[50] V WEB. Psi-k-Ab initio(2021). http://psi-k.net/software/

[51] W KAMINSKY. WinXMorph(2021). http://cad4.cpac.washington.edu/WinXMorphHome/WinXMorph.htm#opennewwindow

[52] K MOMMA. Visualization for electronic and structural analysis(2021). http://www.jp-minerals.org/vesta/en/

[53] S MAHAJAN, S JAGTAP. Metal-oxide semiconductors for carbon monoxide (CO) gas sensing: a review. Applied Materials Today, 18, 100483(2020).

[54] S ZEB, J PENG X, Z YUAN G et al. Controllable synthesis of ultrathin WO₃ nanotubes and nanowires with excellent gas sensing performance. Sensors and Actuators B-Chemical, 305, 127435(2020).

[55] D LIU, W REN X, S LI Y et al. Nanowires-assembled WO₃ nanomesh for fast detection of ppb-level NO₂ at low temperature. Journal of Advanced Ceramics, 9, 17-26(2020).

[56] V OISON, L SAADI, C LAMBERT-MAURIAT et al. Mechanism of CO and O₃ sensing on WO₃ surfaces: first principle study. Sensors and Actuators B-Chemical, 160, 505-510(2011).

[57] H ZHAO L, H TIAN F, B WANG X et al. Mechanism of CO adsorption on hexagonal WO₃(001) surface for gas sensing: a DFT study. Computational Materials Science, 79, 691-697(2013).

[58] H JIN, H ZHOU, F ZHANG Y. Insight into the mechanism of CO oxidation on WO₃(001) surfaces for gas sensing: a DFT study. Sensors, 17, 1898(2017).

[59] L TANG B, H JIANG G, X CHEN W et al. First-principles study on hexagonal WO₃ for HCHO gas sensing application. Acta Metallurgica Sinica-English Letters, 28, 772-780(2015).

[60] X HAN, H YIN X. Density functional theory study of the NO₂-sensing mechanism on a WO₃(001) surface: the role of surface oxygen vacancies in the formation of NO and NO₃. Molecular Physics, 114, 3546-3555(2016).

[61] X QIN Y, M LIU, Y HUA D. First-principles study of the electronic structure and NO₂-sensing properties of Ti-doped W₁₈O₄₉ nanowire. Acta Physica Sinica, 63, 207101(2014).

[62] X QIN Y, H YE Z. DFT study on interaction of NO₂ with the vacancy-defected WO₃ nanowires for gas-sensing. Sensors and Actuators B-Chemical, 222, 499-507(2016).

[63] L BAI S, W ZHANG K, S WANG L et al. Synthesis mechanism and gas-sensing application of nanosheet-assembled tungsten oxide microspheres. Journal of Materials Chemistry A, 2, 7927-7934(2014).

[64] N YAKOVKIN I, M GUTOWSKI. Driving force for the WO₃(001) surface relaxation. Surface Science, 601, 1481-1488(2007).

[66] H YANG H, G SUN H, T LI Q et al. Structural, electronic, optical and lattice dynamic properties of the different WO₃ phases: first-principle calculation. Vacuum, 164, 411-420(2019).

[68] T ZHENG T, W SANG, H HE Z et al. Conductive tungsten oxide nanosheets for highly efficient hydrogen evolution. Nano Letters, 17, 7968-7973(2017).

[70] G WANG F, C DI VALENTIN, G PACCHIONI. Doping of WO₃ for photocatalytic water splitting: hints from density functional theory. Journal of Physical Chemistry C, 116, 8901-8909(2012).

[71] T ZHANG, L ZHU Z, N CHEN H et al. Iron-doping-enhanced photoelectrochemical water splitting performance of nanostructured WO₃: a combined experimental and theoretical study. Nanoscale, 7, 2933-2940(2015).

[72] C HUANG W, X WANG J, L BIAN et al. Oxygen vacancy induces self-doping effect and metalloid LSPR in non-stoichiometric tungsten suboxide synergistically contributing to the enhanced photoelectrocatalytic performance of WO₃-_x/TiO₂-_x heterojunction. Physical Chemistry Chemical Physics, 20, 17268-17278(2018).

[73] N ZHANG, Y LI X, F LIU Y et al. Defective tungsten oxide hydrate nanosheets for boosting aerobic coupling of amines: synergistic catalysis by oxygen vacancies and bronsted acid sites. Small, 13, 1701354(2017).

[74] N ZHANG, A JALIL, X WU D et al. Refining defect states in W₁₈O₄₉ by Mo doping: a strategy for tuning N₂ activation towards solar-driven nitrogen fixation. Journal of the American Chemical Society, 140, 9434-9443(2018).

[75] N ZHANG, R LONG, C GAO et al. Recent progress on advanced design for photoelectrochemical reduction of CO₂ to fuels. Science China-Materials, 61, 771-805(2018).

[76] Q LI M, N ZHANG, R LONG et al. PdPt alloy nanocatalysts supported on TiO₂: maneuvering metal-hydrogen interactions for light-driven and water-donating selective alkyne semihydrogenation. Small, 13, 1604173(2017).

[77] Z WANG, Y WANG X, S CONG et al. Fusing electrochromic technology with other advanced technologies: a new roadmap for future development. Materials Science & Engineering R-Reports, 140, 100524(2020).

[78] J YAO Y, Q ZHAO, W WEI et al. WO₃ quantum-dots electrochromism. Nano Energy, 68, 104350(2020).

[79] H LIN, F ZHOU, P LIU C et al. Non-grotthuss proton diffusion mechanism in tungsten oxide dihydrate from first-principles calculations. Journal of Materials Chemistry A, 2, 12280-12288(2014).

[80] A HJELM, G GRANQVIST C, M WILLS J. Electronic structure and optical properties of WO₃, LiWO₃, NaWO₃, and HWO₃. Physical Review B, 54, 2436-2445(1996).

[81] J WISEMAN P, G DICKENS P. Neutron-diffraction studies of cubic tungsten bronzes. Journal of Solid State Chemistry, 17, 91-100(1976).

[82] S YANG, J CHA, C KIM J et al. Monolithic interface contact engineering to boost optoelectronic performances of 2D semiconductor photovoltaic heterojunctions. Nano Letters, 20, 2443-2451(2020).

[85] P KOCER C, J GRIFFITH K, P GREY C et al. Cation disorder and lithium insertion mechanism of Wadsley-Roth crystallographic shear phases from first principles. Journal of the American Chemical Society, 141, 15121-15134(2019).

[86] A KARIM N, K KAMARUDIN S, K SHYUAN L et al. Study on the electronic properties and molecule adsorption of W₁₈O₄₉ nanowires as a catalyst support in the cathodes of direct methanol fuel cells. Journal of Power Sources, 288, 461-472(2015).

[87] F ZHANG Z, L CHEN J, B LI H et al. Vapor-solid nanotube growth via sidewall epitaxy in an environmental transmission electron microscope. Crystal Growth & Design, 17, 11-15(2017).

[88] F ZHANG Z, Y WANG, B LI H et al. Atomic-scale observation of vapor-solid nanowire growth via oscillatory mass transport. ACS Nano, 10, 763-769(2016).

[89] F ZHANG Z, P SHENG L, L CHEN et al. Atomic-scale observation of pressure-dependent reduction dynamics of W₁₈O₄₉ nanowires using environmental TEM. Physical Chemistry Chemical Physics, 19, 16307-16311(2017).

[90] L CHEN, S LAM, H ZENG Q et al. Effect of cation intercalation on the growth of hexagonal WO₃ nanorods. Journal of Physical Chemistry C, 116, 11722-11727(2012).

[91] S JIANG, M CHEKINI, B QU Z et al. Chiral ceramic nanoparticles and peptide catalysis. Journal of the American Chemical Society, 139, 13701-13712(2017).

[92] J GU L, L MA C, H ZHANG X et al. Populating surface-trapped electrons towards SERS enhancement of W₁₈O₄₉ nanowires. Chemical Communications, 54, 6332-6335(2018).

[93] F MEHMOOD, R PACHTER, R MURPHY N et al. Effect of oxygen vacancies on the electronic and optical properties of tungsten oxide from first principles calculations. Journal of Applied Physics, 120, 233105(2016).

[94] B MIGAS D, L SHAPOSHNIKOV V, N RODIN V et al. Tungsten oxides. I. Effects of oxygen vacancies and doping on electronic and optical properties of different phases of WO₃. Journal of Applied Physics, 108, 093713(2010).

[95] W SAI L, L TANG L, M HUANG X et al. Lowest-energy structures of (WO₃)_n(2≤n≤12) clusters from first-principles global search. Chemical Physics Letters, 544, 7-12(2012).

[96] X HUANG, J ZHAI H, J LI et al. On the structure and chemical bonding of tri-tungsten oxide clusters W₃O_n^- and W₃O_n (n=7-10): W₃O₈ as a potential molecular model for O-deficient defect sites in tungsten oxides. Journal of Physical Chemistry A, 110, 85-92(2006).

[98] G JIANG P, Y XIAO Y, J LIU W et al. Hydrogen reduction characteristics of WO₃ based on density functional theory. Results in Physics, 12, 896-902(2019).

[99] J LIU W, G JIANG P, Y XIAO Y et al. A study of the hydrogen adsorption mechanism of W₁₈O₄₉ using first-principles calculations. Computational Materials Science, 154, 53-59(2018).