Ozone electrogeneration on Pt-TaOy sol-gel film modified titanium electrode: Effect of electrode composition on the electrocatalytic activity

Abstract

This work examines the ozone electrogeneration (OE) at a binary coating of different nominal compositions (Pt)x-(TaOy)(100-x), where x (percentage in the precursor solution) varied between 1% and 100%, coated on titanium substrate prepared by a sol-gel technique. The OE is performed in an artificial tap water at room temperature (25°C). The percentages of Pt and TaOy in the coating significantly affect the electrocatalytic activity towards oxygen evolution. The oxygen evolution was retarded to a different extent based on the electrode composition. The largest retardation was obtained at the (Pt)10-(TaOy)90 electrode (ca. 480 mV positive shift) as compared with the (Pt)100-(TaOy)0 electrode. This was reflected in a high current efficiency (CE) of OE (ca. 19.3%) at the former electrode. This value is considered to be among the highest values reported for OE at 25°C in neutral media. The composite electrodes were characterized by voltammetric and surface techniques. A plausible explanation for the change of the efficiency of OE with the electrode composition is given based on the electrochemical results.