Novel Z-scheme In2S3/Bi2WO6 core-shell heterojunctions with synergistic enhanced photocatalytic degradation of tetracycline hydrochloride

Semiconductor photocatalytic technology is an effective strategy to cope with the current environmental issues. Therefore, the development of low-cost and environment-friendly catalysts with high efficacy has become a research focus and emphasis. Herein, novel Z-scheme In2S3/Bi2WO6 core-shell structure composites were controllably prepared by template and hydrothermal route. Highly improved photocatalytic degradation of tetracycline hydrochloride (TCH) over In2S3/Bi2WO6 core-shell composites was observed under visible-light (VL) irradiation (similar to 96.0%), which was 2.4 and 2.1 folds higher than that of In2S3 and Bi2WO6, respectively. The excellent oxygen activation and catalytic performance was ascribed to the synergistic effects of built-in electric field to ensure easy charge exchange at the interface of In2S3 and Bi2WO6, Z-scheme charge transfer path and the extended range of VL absorption. Superoxide radical (.O-2) and hydroxyl (.OH) radicals were verified to be involved in the photocatalytic reaction by the active species capture experiment and the electron spin response (ESR) detection. The recycling experiments demonstrate the excellent stability and reusability of the In2S3/Bi2WO6. In addition, in accordance with the experimental results, the highly efficient Z-scheme photocatalytic mechanism and degradation paths were proposed. This work provided a new way for preparation of Z-scheme core-shell composites which had broad applications prospect in environmental remediation.