Preparation of Graphene Sponge Coated Iron Electrode for the Electrolytic Decoloration of Methylene Blue

Xiaoliang Zhang, Jingru Xie, Sheng-Tao Yang, Fumin Xue

Electrolysis is a widely adopted technology in water treatment, while the major challenge focuses on developing better electrode materials. In this study, we reported that the hydrothermal coating of graphene sponge (GS) on Fe electrode (GS-Fe electrode) could significantly improve the decoloration performance of Fe electrode. The decoloration kinetics constant of GS-Fe electrode was five times of that of Fe electrode at the same current density. Mechanistically, the electrolytic oxidation of MB was via indirect pathway, where Cl^- was oxidized into ClO^- for the oxidation of other substances. Moreover, the performance of GS-Fe electrode remained nearly unchanged in the recycling evaluations. The implication to the applications of GS-Fe electrode in water treatment is discussed.