Preparation and characterization of novel Niln2S4/UiO-66 photocatalysts for the efficient degradation of antibiotics in water

Photocatalysis is considered an economical, environmentally friendly, and effective technology for removing pollutants. The construction of Z-Scheme heterojunctions has been identified as one of the feasible solutions capable of enhancing the photocatalytic activity. Herein, a series of visible light responsive photocatalysts (NiIn2S4/UiO-66 composites) with excellent activity and stability were prepared by using a solvothermal process. It is found that 20 mg L-1 of tetracycline (TC) could be almost completely degraded under visible light irradiation within 1 h, when the mass ratio of NiIn2S4 to UiO-66 is 0.5:1 (NISU-0.5) and the solution pH = 11. In addition, after six cycles, the degradation rate of tetracycline photocatalyzed by NISU-0.5 still reach up to 90%. Ultraviolet photoelectron spectra (UPS), X-ray photoelectron spectra (XPS) and electron spin resonance measurements (ESR) confirm the formation of the Z-Scheme heterostructure between NiIn2S4 and UiO-66. The synergistic effect between built-in electric field, energy band bending and coulomb interactions in interface of Z-Scheme heterojunction is conducive to restrain the recombination of photogenerated electrons and holes, which greatly improve the photocatalytic activity. In conclusion, this study offers a new thought for design and synthesis of Z-Scheme heterojunctions and provides a cost-effective strategy for solving environmental pollution and energy problems in the future.