Construction of Z-scheme Bi3TaO7/Zn0.5Cd0.5S composites with high efficiency for levofloxacin degradation under visible light irradiation

Abstract

Direct Z-scheme Bi₃TaO₇/Zn_0.5Cd_0.5S composite photocatalysts were successfully prepared via an in situ growth hydrothermal method. The photocatalytic activities of composites were investigated by the degradation of levofloxacin under visible light. All composites exhibited enhanced photocatalytic activities compared with Bi₃TaO₇ and Zn_0.5Cd_0.5S. The structure composition and photoelectric performance of the photocatalysts were investigated by related experiments. The dominant active species (h⁺ and ˙O₂⁻) during levofloxacin degradation were identified through capture experiments. Meanwhile, the stability and cyclicity of the optimal photocatalyst (BZCS-2) were studied by cycling experiments. Finally, we proposed a possible direct Z-scheme charge-migration mechanism for levofloxacin degradation. This work would provide a feasible idea and theoretical support for the in-depth research of direct Z-scheme photocatalysts and Zn_xCd_1−xS-based semiconductor materials in the future.