Deposition of Bivo4 on the Floating Lightweight Hollow Sponge Carbon Nitride for Efficient Photocatalytic Degradation of Tetracycline by S-Scheme Heterojunction and the Ecotoxicity Assessment of the Products

Abstract

In this study, the floating lightweight hollow sponge carbon nitride containing BiVO4 (BVO/LHSCN) was constructed using calcination and hydrothermal methods. The S-scheme charge transfer path of BVO/LHSCN and its unique porous network floating structure achieve BVO/LHSCN excellent light capture ability, photogenerated carrier separation efficiency and recycling performance. After 180 minutes of illumination, BVO/LHSCN can degrade 94.9% of tetracycline (TC), with a rate constant as high as 0.06235 min-1, which was 4.35 times and 7.7 times higher than that of pure BVO (0.01433 min-1) and LHSCN (0.00807 min-1), respectively. After 5 cycles of experiment, BVO/LHSCN still exhibited excellent TC degradation performance, demonstrating outstanding stability. Subsequently, the intermediate product and degradation pathway during the TC degradation were analyzed by LC-MS. The possible ecological risks of the intermediate and final products were assessed, determining a low environmental risk in the degradation process of tetracycline. This study provides a novel method f to improve the light-capturing ability of S-scheme heterojunction photocatalysts.

Keywords: BiVO4, g-C3N4, S-scheme heterojunction, floating photocatalyst, hollow structure