Fabrication of novel three-dimensional Fe3O4-based particles electrodes with enhanced electrocatalytic activity for Berberine removal

Abstract

Reasonable design of three-dimensional (3D) catalytic particle electrodes (CPEs) is crucial for achieving efficient electrocatalytic oxidation of organic pollutants. Herein, the novel Fe₃O₄/SnO₂/GO (FO/SO/GO) particle electrode has been developed and serviced to the 3D electrocatalytic berberine hydrochloride oxidation system with DSA (RuO₂-IrO₂-SnO₂/Ti) electrode as anode and GDE (gas diffusion electrode) electrode as the cathode. Compared with 2D systems and other CPEs, FO/SO/GO electrode shows excellent electrocatalytic activity and remarkable stability for BH removal, that is, the removal rate of BH is 94.8% within 90 min, and the rate constant is 0.03095 min^-1. More importantly, after five cycles, the ternary composite still maintains a strong ability to oxidize pollutants. The structural characterization and electrochemical measurement further uncover that the electron transfer ability and electrocatalytic oxidation efficiency are highly dependent on the surface structure regulation of CPEs. Furthermore, the quenching experiments show that hydroxyl radicals are the main active species in the 3D electro-Fenton (EF) system, which can oxidize BH molecules adsorbed on the surface of GO to CO₂, H₂O, or other products. The results could potentially provide new insights for designing and fabricating more stable and efficient 3D CPEs electrocatalytic removal of organic pollutants in the future.

Keywords: BH removal; Electrocatalytic oxidation; FO/SO/GO CPEs; Magnetic separation; Mechanism.