Z scheme Bi2WO6/CuBi2O4 heterojunction mediated by interfacial electric field for efficient visible light photocatalytic degradation of tetracycline
Abstract In order for the removal of Tetracycline (TC) in wastewaters, an efficient binary Bi2WO6/CuBi2O4 Z scheme heterojunction photocatalyst was synthesized by loading Bi2WO6 (BWO) nanoparticles on CuBi2O4 (CBO) nanorods via a solvothermal route. The obtained Bi2WO6/CuBi2O4 composite displays photocatalytic activity for TC degradation more than five times higher than that for pure CBO nanorods. The recycling experiment shows that over 91% of TC can be photo degraded by the optimal Bi2WO6/CuBi2O4 photocatalyst within 60 min even after four cycles. Results of SEM, transient photocurrent response, EIS measurement prove that solvothermal process for BWO loading can introduce rough surface with high density negative charge on CBO, contributing to effective photo induced carrier transfer. XPS, Mott Schottky plots and PL spectra reveal that the loading of BWO as well as interfacial charge redistribution can induce the formation of interfacial electric field for Z scheme heterojunction, contributing to the high oxidation and reduction capabilities ability of Bi2WO6/CuBi2O4 composite. The study on photocatalytic mechanism discloses that hole (h+ and superoxide radical O2 are dominating reactive oxidation species (ROS) in the photodegradation process. This study has provided a novel route to fabricate Z scheme photocatalysts for effective photocatalytic degradation processes.
Chemical Engineering Journal