전기화학적 하이포아염소산 생산을 위한 Multi-layered Sb-SnO2/IrTaOx/TNT 전극 개발

Abstract

In this paper, the multi-layered Sb-SnO2/IrTaOx/TNT anode that reduces the use of noble metals and increases the efficiency of hypochlorous acid(HClO) production was prepared to replace noble metal-based DSA anode. We report that the Sb-SnO2/IrTaOx/TNT anode has nanotube structure with about 50nm of diameter. Titanium nanotube(TNT) with large surface area was formed by anodization of Ti plates and used as a substrate to improve catalytic activity and current efficiency. Also, IrTaOx inter-layer was introduced to increase ohmic contact. Sb-SnO2 having a high oxygen evolution potential was used as an active oxide layer. To investigate the effect of porous structure on the hypochlorous acid production, the Sb-SnO2/IrTaOx/TNT electrode was compared with the Sb-SnO2/IrTaOx/Ti electrode made of Ti plate. The titanium nanotube based-electrode showed 10~20% higher current efficiency than the titanium plate based-electrode. Comparing with the conventional DSA electrodes, the Sb-SnO2/IrTaOx/TNT electrode have 30~40% higher hypochlorous acid(HClO) production efficiency even with a small amount of noble metals. Also, we optimized the condition of anodization for titanium nanotube preparation and Sb, Sn electrodeposition conditions. The effect of each parameter was evaluated by comparing the structure of the prepared electrode, the catalyst distribution of IrTaOx and Sb-SnO2 layer and the efficiency of hypochlorous acid production. In addition, we explained how antimony and tin affect Cl- oxidation.