Novel Ti/Ta₂O₅-SnO₂ electrodes for water electrolysis and electrocatalytic oxidation of organics

Mixed metal oxide (MMO) electrodes have been applied to different technologies including chlorine production, organic compounds oxidation, water electrolysis, electroplating, etc. due to their catalytic, optical and electronic properties. Most of the existing MMO electrodes contain either toxic metals or precious metals of the platinum group. The aim of this study was to develop environmentally friendly and cost-effective MMO electrodes for water and organic compounds oxidation. Ti/Ta₂O₅-SnO₂ electrodes of different nominal composition were prepared, and electrochemically and physically characterized. For water oxidation, Ti/SnO₂ electrode with 5 at.% of Ta produced the highest electroactivity. Ti/SnO₂ electrode with 7.5 at.% of Ta showed the best performance for the oxidation of methylene blue (MB). The electrocatalytic activity of the Ti/Ta ₂O₅-SnO₂ electrodes increased with the number of active layers. The maximum current of water oxidation reached 3.5 mA at 2.5 V when the electrode was covered with ten layers of Ta₂O₅. In case of the oxidation of 0.1 mM MB, eight and ten active layers of Ta ₂O₅ significantly increased the electrode activity. The prepared electrodes have been found applicable for both water electrolysis and organic compounds oxidation.