Facile synthesis of Ni-doped ZnS nanostructures and their photocatalytic activity to RhB

In this paper, pure ZnS and Ni-doped ZnS nanostructures (Ni-ZnS) were prepared by facile template-free hydrothermal method. The as-prepared Ni-ZnS was characterized by XRD, SEM, EDS, XPS, and UV-Vis DRS. The effects of different Ni doping amounts and hydrothermal reaction temperatures were investigated. The photocatalytic ability was evaluated for the degradation of Rhodamine B (RhB) under visible light irradiation. The results indicated that the doping of Ni effectively enhanced the photocatalytic activity of pure ZnS. Ni-ZnS exhibited significantly enhanced photocatalytic properties, the reaction rate constant (0.01154 min(-1)) is higher than that of pure ZnS (0.00218 min(-1)). Carrier separation efficiency and charge transport efficiency were investigated by transient photocurrent response (TPS) and electrochemical impedance spectroscopy (EIS). Scavenger test was used to determine the role of active species, combining the analysis results of UV-Vis DRS, TPS, and EIS, accordingly the photocatalytic mechanism of Ni-ZnS was proposed.