Electrocatalytic degradation of bromocresol green wastewater on Ti/SnO2-RuO2 electrode.

Thermal decomposition method was employed to prepare a Ti/SnO2-RuO2 electrode, on which electrocatalytic degradation of bromocresol green (BCG) was investigated in detail. Scanning electron microscopy, an X-ray diffraction analyzer and an X-ray fluorescence spectrometer were adopted to characterize the morphology, crystal structure and element analysis of the as-prepared Ti/SnO2-RuO2 electrode. It was indicated that the Ti/SnO2-RuO2 electrode had a 'cracked-mud' structure and exhibited a superior specific surface area. The removal efficiency of BCG on the Ti/SnO2-RuO2 electrode was determined in terms of chemical oxygen demand and ultraviolet-visible absorption spectrometry. The results of the batch experiment indicated that the removal efficiency of BCG was influenced by the following factors in descending order: initial pH0, reaction temperature, current density and electrolysis time. The removal efficiency of BCG reached up to 91% at the optimal experiment conditions (initial concentration of 100 mg L-1, initial pH0 7, reaction temperature of 30 °C, current density of 12 mA cm-2 and electrolysis time of 150 min). As a result, it was concluded that BCG wastewater was efficiently removed by electrochemical oxidation on the Ti/SnO2-RuO2 electrode.