Environmentally Friendly Fabrication of Ti/RuO <sub>2</sub> -IrO <sub>2</sub> -SnO <sub>2</sub> -Sb <sub>2</sub> O <sub>5</sub> Anode with In Situ Incorporation of Reduced TiO <sub>2</sub> Interlayer
Jingru Wang, Xuchen Ba, Zekun Zhao, Juan Wang, Qipeng Yang, Yijie Liu, Bo Jiang
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 H 2 and N 2 (molar ratio 1:5) without chemicals consumption and wastewater discharge. It was found that the reduced TiO 2 interlayer could be favorably created at temperature of 750 °C. This rendered Ti/reduced TiO 2 /RuO 2 -IrO 2 -SnO 2 -Sb 2 O 5 anode with better stability and higher electrocatalytic activity. The accelerated lifetime for Ti/reduced TiO 2 /RuO 2 -IrO 2 -SnO 2 -Sb 2 O 5 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/RuO 2 -IrO 2 -SnO 2 -Sb 2 O 5 electrode. As compared with the counterparts, Ti/reduced TiO 2 /RuO 2 -IrO 2 -SnO 2 -Sb 2 O 5 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 TiO 2 on the substrate. Generally, an environmentally friendly Ti substrate pretreatment method was developed and demonstrated promising for upgrading DSA fabrication process in industrial application.