Galvanic Corrosion of Zero-Valent Iron to Intensify Fe2+ Generation for Peroxymonosulfate Activation

Abstract Zero-valent iron (ZVI) usually activates peroxymonosulfate (PMS) through the generation of Fe2+ from the self-corrosion of ZVI in a Fenton-like reaction. However, the generation rate of Fe2+ forms the reaction rate-limiting step. Against this, a microscopic Fe-graphitic carbon galvanic cell array (GCA) was created to intensify the PMS activation process. The synergistic effect between a ZVI anode and a graphitic carbon cathode accelerated the generation of Fe2+ via ZVI galvanic corrosion to significantly increase the PMS activation performance. Distinctive short-circuiting of the anode and cathode in GCA effectively enhanced the galvanic corrosion. The electrochemical behavior of GCA was characterized in detail to elucidate the PMS activation mechanism. The microscopic Fe-graphitic carbon galvanic cell array provided a promising pathway for pollutant remediation.