PbO2 electrodes prepared by pulse reverse electrodeposition and their application in benzoic acid degradation

Abstract

In this work, PbO2 electrodes were prepared by pulse reverse current (PRC) electrodeposition. The effect of different duty cycles was investigated, which confirms that PRC deposition is an effective technique to optimize PbO2 electrodeposition. Surface morphologies and crystal structures of the PbO2 electrodes were characterized, and the voltammetric study was conducted to elucidate their electrochemical behavior. PRC deposition markedly changed the crystal structural and morphologic features of the resulting PbO2 electrodes, giving rise to the increased content of β phase and a rough surface morphology. High-performance liquid chromatography (HPLC) was employed to monitor the galvanostatic electrolysis of benzoic acid (BA) occurring over the PbO2 electrodes. A pseudo first-order reaction was found to well fit these BA degradation reactions, and the highest degradation efficiency was observed for the PbO2 electrode made from 95% duty cycle. Concurrently, main aromatic intermediates and carboxylic acids generated in the BA degradation were identified, and a probable pathway was proposed for the BA degradation course on the PbO2 anode.