Ozone electrogeneration at a high current efficiency using a tantalum oxide–platinum composite electrode

This work examines the ozone (O3) electrogeneration at a tantalum oxide (TaOx) and Pt composite-coated Ti (Pt–TaOx/Ti) electrode in comparison with a smooth Pt electrode. Pt–TaOx/Ti electrode was prepared by thermal decomposition procedure. O3 has been electrogenerated galvanostatically (100 mA cm−2) at room temperature in the presence of neutral supporting electrolyte using a Nafion membrane cell. A superior catalytic activity of the Pt–TaOx/Ti electrode towards O3 evolution was observed. The current efficiency (ca. 11.7%) for O3 generation at the Pt–TaOx/Ti electrode was found to be much higher than that (0.7%) obtained at smooth Pt electrode of the same geometrical area. The oxygen evolution overvoltage was found to be the controlling factor in O3 electrogeneration. The stability of the composite electrode was examined by applying a constant current (50 mA cm−2) and then following the change in the electrode potential and current efficiency with time. SEM images proved the cracked-structure in the Pt–TaOx/Ti electrode and no apparent significant change in the morphology upon electrolysis.