Effect of Electrode Material on Electrodeposition of Tungsten Oxide

Resumo

Influence exerted by the nature of an electrode-substrate on the electrochemical deposition of tungsten oxides from a metastable acid solution of isopolytungstate was studied. As substrates for obtaining tungsten oxide deposits served metallic electrodes made of gold and platinum, films of mixed indium-tin oxide on glass (ITO-electrodes) and also glassy carbon electrodes and glassy carbon electrodes coated with films of conducting polymers: polyaniline, polypyrrole, and poly-3,4-ethylenedioxythiophene. It was shown that the nature of a substrate noticeably affects the electrochemical properties of tungsten oxide deposits. These differences are attributed to the adsorption of hydrogen on platinum in the range of the deposition potentials of tungsten oxide and to the chemical interaction of polytungstate ions with the thiophene sulfur of the polymer.