Deposition of thin TiO2 layers on platinum by means of cyclic voltammetry of selected complex Ti(IV) media leading to anatase

Thin layers of anatase TiO2, up to 1 μm, were produced on the surface of a platinum electrode by means of cycling voltammetry from the aqueous solutions of the peroxo-oxalate complexes and the oxalate complexes of titanium(IV). Mechanisms of TiO2 electrodeposition as well as different electrochemical reactions causing pH changes at the electrode were studied. The electroreduction processes of hydrogen peroxide and nitrite ion on platinum cause the highest pH changes. Values of the molar ratio of Ti(IV)/H2O2 should be kept closely to 0.5.In all cases studied, the electrodeposition led to the partially decomposed amorphous oxalate compounds of titanium(IV), which can be converted into crystalline anatase above 500 °C in air. The thermal behaviour of TiO2 precursor compounds was examined by DRIFTS and TG–DTA methods. Strong effects of K+ and NH4+ ions on the electrodeposition process were found by using of the EQCM technique, Raman spectroscopy and XRD measurements. The ammonium electrolyte warrants purity of the anatase phase.Morphology of the oxide films produced in different solvents was examined by SEM.