Environmentally Friendly Fabrication of Ti/RuO2-IrO2-SnO2-Sb2O5 Anode with In Situ Incorporation of Reduced TiO2 Interlayer

Abstract

The intensive use of chemical reagents in the pretreatment of Ti substrate and shorter electrode life constrict the wider application of the dimensionally stable anode (DSA). In this study, a simple method was developed to thermally pretreat the Ti substrate in the atmosphere of H2 and N2 (molar ratio 1:5) without chemicals consumption and wastewater discharge. It was found that the reduced TiO2 interlayer could be favorably created at temperature of 750 °C. This rendered Ti/reduced TiO2/RuO2-IrO2-SnO2-Sb2O5 anode with better stability and higher electrocatalytic activity. The accelerated lifetime for Ti/reduced TiO2/RuO2-IrO2-SnO2-Sb2O5 electrode was 65 h with the optimum catalyst loading amount (2.6 ± 0.05 mg cm−2), while it was only 50 h for traditional Ti/RuO2-IrO2-SnO2-Sb2O5 electrode. As compared with the counterparts, Ti/reduced TiO2/RuO2-IrO2-SnO2-Sb2O5 with higher oxygen evolution potential (1.42 V/SCE) and lower chlorine evolution potential (1.12 V/SCE), suggesting higher electro-catalytic activity toward reactive oxidative species formation. The deactivation test indicates that the anode deactivation mainly proceeded via the dissolution of the catalyst layer and then formation of insulated TiO2 on the substrate. Generally, an environmentally friendly Ti substrate pretreatment method was developed and demonstrated promising for upgrading DSA fabrication process in industrial application.