Efficient degradation of tetracycline in actual water systems by 2D/1D g-C3N4/BiOBr Z-scheme heterostructure through a peroxymonosulfate-assisted photocatalytic process

Abstract

Constructing heterojunction is an efficient strategy to overcome the deficiency of single-component photocatalysts on peroxymonosulfate (PMS) activation. Herein, we combined 2D g-C3N4 nanosheets with diverse dimensional BiOBr to construct Z-scheme g-C3N4/BiOBr heterojunctions and used them to activate PMS for the degradation of tetracycline (TC) efficiently. In our experiments, 2D/1D g-C3N4/BiOBr NRs heterojunction/PMS/Vis system exhibits the maximum photocatalytic apparent rate constant, approximately 6.2 times larger than that of the g-C3N4/PMS/Vis system. The results reveal that the specially designed 2D/1D Z-scheme heterojunction is essential to activating PMS for the highly efficient degradation of TC under visible-light illumination. The enhanced performance is possible due to the formation of 2D/1D Z-scheme heterojunction promoting the specific surface area and photo-excited charge separation efficiency and greatly accelerating PMS activation to yield high active SO4•− radical. The photoelectrical test results and the active species trapping experiment confirm that g-C3N4/BiOBr NRs heterojunction has excellent charge separation ability and can effectively activate PMS to form SO4• −. This work provides a new direction for the highly efficient activation of peroxymonosulfate by 2D/1D Z-scheme heterojunction to remove TC effectively.