Construction of Highly Active Zn3In2S6 (110)/g-C3N4 System by Low Temperature Solvothermal for Efficient Degradation of Tetracycline under Visible Light

Abstract

Herein, Zn₃In₂S₆ photocatalyst with (110) exposed facet was prepared by low temperature solvothermal method. On this basis, a highly efficient binary Zn₃In₂S₆/g-C₃N₄ was obtained by low temperature solvothermal method and applied to the degradation of tetracycline (TC). The samples of the preparation were characterized by X-ray diffraction, scanning electron microscope, transmission electron microscope, UV-vis diffuse reflection spectroscopy, and photoluminescence spectroscopy. Furthermore, the degradation performance of photocatalysts on TC was investigated under different experimental conditions. Finally, the mechanism of Zn₃In₂S₆/g-C₃N₄ composite material degrading TC is discussed. The results show that Zn₃In₂S₆ and Zn₃In₂S₆/g-C₃N₄ photocatalysts with excellent performance could be successfully prepared at lower temperature. The Zn₃In₂S₆/g-C₃N₄ heterojunction photocatalyst could significantly improve the photocatalytic activity compared with g-C₃N₄. After 150 min of illumination, the efficiency of 80%Zn₃In₂S₆/g-C₃N₄ to degrade TC was 1.35 times that of g-C₃N₄. The improvement of photocatalytic activity was due to the formation of Zn₃In₂S₆/g-C₃N₄ heterojunction, which promoted the transfer of photogenerated electron-holes. The cycle experiment test confirmed that Zn₃In₂S₆/g-C₃N₄ composite material had excellent stability. The free radical capture experiment showed that ·O₂^- was the primary active material. This study provides a new strategy for the preparation of photocatalysts with excellent performance at low temperature.

Keywords: Zn3In2S6/g-C3N4; low temperature; photocatalytic; tetracycline.