Tantalum Oxide Thin Film on a Pt-Decorated Glass Substrate for pH-Sensing Application of Drinking Water

TaO film @ Pt-decorated glass was deposited through the reactive magnetron sputtering using pure tantalum and oxygen integrated Ar environment. The film properties were studied through XRD, FE-SEM and AFM techniques. Oxidation-reduction potential (ORP) was measured using three-electrodes arrangement with buffer solutions of pH value 1, 7 and 14. Solutions were prepared using H2SO4 and KOH in deionized water. There was a positive shift of the oxidation peak and change in the area of cyclic voltammogram with the pH-value. Owing to good stability and linear response, TaO @ Pt film can be used as a sensing electrode in pH-measuring devices.