Improving photocatalytic performance of ZnIn2S4 loaded with cocatalysts

ZnIn2S4 was synthesized by hydrothermal method. PdS, SrS, Pt, Ru were respectively loaded onto ZnIn2S4 as cocatalyst. PdS and noble metal co-loaded photocatalyst were also prepared. The samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV-visible diffuse reflectance spectroscopy (UV-Vis). The results indicated that all the samples were of the same crystalloid structures and optical properties. The formation of PdS could be evidenced by XPS analysis results. PdS and noble metal co-loaded can interact with each other and cooperate on improving the photocatalytic activity. The highest photocatalytic activity was observed on ZnIn2S4 co-loaded with 0.5 wt% PdS and 0.5 wt% Pt, with the rate of hydrogen evolution to be 1.79 mmol/h, which was ca. 19 times more than that of ZnIn2S4. The possible coordinated mechanism was discussed.