Electrodeposited SiO2 film: a promising interlayer of a highly active Ti electrode for the oxygen evolution reaction

Abstract

Ti-supported IrO₂ or RuO₂ oxide coated electrodes are widely used for the oxygen evolution reaction (OER) in acidic media. Electrocatalytic activity and long-term stability need to be further improved for these types of electrodes. A highly porous and well-adhered electrodeposited SiO₂ (e-SiO₂) film is proposed as the interlayer in this work to meet the above-mentioned requirements. The results show that the active oxide fully fills in the porous network throughout the whole thickness of the e-SiO₂ film, to form “total-depth” highly porous oxide electrocatalytic coatings. For this reason, more than 1 order of magnitude higher apparent activity towards the OER at the Ti/e-SiO₂/IrO₂ (or RuO₂) electrode is achieved compared to that of the conventional Ti/IrO₂ or Ti/RuO₂ electrode. Literature survey indicates that these novel electrodes are one of the most active Ti electrodes ever reported. The service life of this type of electrode is also obviously enhanced due to the “inter-locking” structure formed between the active oxide layer and e-SiO₂ film.