A Defect-Mediated Wo3/Feooh Heterostructure as Z-Scheme Photocathode for Efficient Water Purification Via Persulfate Activation

Abstract

This work reports sulphate radical assisted photoelectrocatalytic (SR-PEC) degradation of tetracycline using a visible light active FeOOH/WO3 loaded on carbon cloth (FeOOH/WO3) photocathode. During the in situ electroreduction process, the intervention of external electrons increases the lattice spacing of WO3, facilitating the formation of oxygen defects causing a decrease in the Fermi energy level, and accelerating the transfer of electrons from the conduction band of WO3 to the valence band of FeOOH to construct a Z-scheme heterojunction. Compared to WO3 photocathode, FeOOH/WO3 exhibited 6.13 times higher tetracycline degradation kinetics. Trapping experiment revealed that the photogenerated holes, sulphate radicals and hydroxyl radicals were the oxidants that significantly took part in the degradation of tetracycline.

Keywords: Persulfate, Photoelectrocatalysis, Defect, FeOOH/WO3, Z-scheme heterostructure