Films of bismuth and nickel tungstates were obtained by chemical and electrochemical synthesis. Bismuth tungstate was obtained by ionic layering and electrochemical deposition. Nickel tungstate (NiWO4) was obtained by combined synthesis methods: 1st - electrochemical synthesis and 2nd - combined electrochemical and thermochemical synthesis. The obtained materials have good adhesion with an optically transparent SnO2 substrate. It is shown that the mechanism of electrochemical formation of Bi2WO6 and NiWO4 films is similar to the processes of WO3 formation as a result of electroreduction of peroxide-complex compounds based on tungstate ions, which were studied in detail in. From the data of coloring kinetics the speed, efficiency and stability of electrochromic material depending on its cycling time are estimated. It is shown that tungstates can cycle for a long time with galvanostatic current change and different potentials. Comparison of electrochromic properties of nickel and bismuth tungstate films obtained by ionic stratification, electrodeposition and combined electrochemical and thermochemical methods showed that polycrystalline films have a lower color contrast compared to films obtained by electrodeposition. Using X-ray phase analysis, it was found that the structure of the obtained materials depended on the method of production. Comparison of X-ray diffraction data for chemically and electrochemically obtained Bi2WO6 showed that the films obtained by electrochemical deposition have more amorphous structure, possibly with inclusions of orthorhombic Bi2WO6 and hexagonal WO3 crystallites, while the films obtained by ionic layering have a layer of polycrystals, indicates the fine-grained obtained crystallites. The studied properties of Bi2WO6 and NiWO4 meet the requirements for electrochromic materials in terms of providing high color contrast in the visible part of the spectrum.
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