Synthesis of a novel Bi19Cl3S27/Bi2MoO6 Z-type heterojunction for efficient photocatalytic removal of tetracycline antibiotic and Cr(VI): Intermediate toxicity and mechanism insight

Abstract

Novel Bi19Cl3S27/Bi2MoO6 (BCS/BMO) Z-type heterojunctions were synthesized using a straightforward hydrothermal method. Benefiting from the large specific surface area (62.41 m2/g) and the effective separation of photogenerated carriers facilitated by the Z-scheme heterojunction, the BCS/BMO exhibited remarkable improved photocatalytic tetracycline degradation and Cr(VI) reduction efficiency in comparison to BCS, BMO, and their physical mixture. Specifically, the photocatalytic degradation rate constants for TC and Cr(VI) are 0.0209 and 0.0218 min-1, respectively, which are 16.08 and 15.57 times those of BCS, 1.74 and 1.31 times those of BMO, and 2.4 and 1.73 times those of the physical mixture. Additionally, based on density functional theory (DFT) calculations and empirical data, three potential photocatalytic pathways of tetracycline were presented. This study presents a novel approach for designing and synthesizing high-efficiency Z-scheme photocatalysts for the degradation of TC and the reduction of Cr(VI) in wastewater.