Improving Photocatalytic Performance for Hydrogen Generation over Co-Doped ZnIn2S4 under Visible Light

A series of Co-doped ZnIn2S4 photocatalysts were prepared via a solvothermal synthesis method. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and UV-visible (UV-Vis) diffuse reflectance spectroscopy. The results indicated that the Co was successfully incorporated into the ZnIn2S4 lattice as confirmed by XRD and XPS. With increasing Co concentration, the absorption edge of the samples shifted to longer wavelength, while the morphology of ZnIn2S4 was gradually destroyed. Photocatalytic results demonstrated that Co2+ doping could greatly enhance the photocatalytic activity of ZnIn2S4. The optimal amount of Co doping for the ZnIn2S4 photocatalyst was 0.3%(w), which displayed the highest photocatalytic activity. The possible photocatalytic mechanism was discussed.