Abstract:

The decomposition of H₂O₂ at the Ti-based oxide electrode coated with IrO₂, RuO₂ and TiO₂ (Ti/ IrO₂/RuO₂/TiO₂) prepared by thermal decomposition, was investigated in the electrolysis system of constant potential and the non-electrolysis system respectively. Additionally, the influence of the decomposition of H₂O₂ caused by Ti-based oxide electrode on the oxidation of aniline was also investigated. The results showed that both higher loading of oxides and higher pH were able to accelerate the decomposition of H₂O₂ in the non-electrolysis system and in this case the decay of H₂O₂ was mainly caused by the catalytic action of the oxides coating. In the electrolysis system with Ti-based oxides electrode as anode, the decay rate of H₂O₂ increased with increasing anodic potential. In this case, the decay of H₂O₂ involved two mechanisms: catalytic decomposition and electrochemical oxidation. It was also found that the catalytic decomposition of H₂O₂ at the oxides electrode was useless to the oxidation of aniline while the electrochemical oxidation of H₂O₂ was only slightly helpful to the oxidation of aniline. This work suggested that using the appropriate anodes of less H₂O₂ decomposition as well as reasonable potential in the electro-Fenton process could achieve high chemical efficiency of H₂O₂.