Enhanced photocatalytic degradation of tetracycline by SnS₂/Bi₂MoO6_-x heterojunction: Multi-electric field modulation through oxygen vacancies and Z-scheme charge transfer

Designing low-cost and efficient photocatalysts for the degradation of antibiotic contaminants in water is crucial for environmental remediation. In this study, we synthesized SnS2/Bi2MoO6-x composites with a synergistic modulation of oxygen vacancies (OVs) and a Z-scheme charge transfer mechanism using a simple hydrothermal method. The synthesized composites, designated as SBMO-5, were used for the photocatalytic degradation of tetracycline (TC). Notably, SBMO-5 exhibited the highest reaction rate constant (0.01385 min(-1)), surpassing pristine SnS2 (0.00129 min(-1)) and Bi2MoO6 (0.00312 min(-1)) by 10.7 and 4.4 times, respectively. The enhanced photocatalytic degradation performance can be ascribed to the synergistic effect of the Z-scheme electron transfer mechanism and OVs. The unique Z-scheme electron transfer channel both accelerated the separation of photogenerated charge carriers and exploited the strongest oxidation and reduction capabilities within the constituent materials. Furthermore, the low-cost and readily available OVs modification enhanced absorption of visible light. Additionally, we investigated the influence of various experimental conditions on the degradation efficiency of SBMO-5, predicted the degradation pathways of TC, and evaluated the toxicity of the intermediates. Overall, this study provides insights into the application of efficient catalysts for pollutant degradation under a multi-electric field modulation strategy.