Efficient oxidative dissolution of V2O3 by the in situ electro-generated reactive oxygen species on N-doped carbon felt electrodes

Abstract

Oxidative dissolution is a critical step for the efficient remediation of heavy metal oxides in large-scale solid wastes. In the present study, a novel electro-oxidative dissolution process of V2O3 to VO43− is achieved by the in-situ generated reactive oxygen species on the N-doped carbon felt cathode in alkaline media. The electro-catalytic HO2− generation and hydrophilic behavior were significantly enhanced by the introduction of nitrogen-containing functional groups. Besides, the mechanism of electrochemical vanadium conversion is systematically illustrated, and a vanadium self-induced electro-Fenton-like reaction is proposed. By employing the radical quenching and ESR measurements, the contributions for V(III) dissolution is determined to be 43.5% by HO2− and 56.5% by hydroxyl radicals, respectively. It should be noted that the V2O3 solid particles can be efficiently dissolved via adsorption-reaction scheme on the carbon felt electrode. This novel electrochemical strategy provides a promising solution for the heavy metal oxide treatment and further understanding for the in situ reactive oxygen species.