Enhanced photocatalytic hydrogen evolution activity of CuInS2 loaded TiO2 under solar light irradiation

Highlight
• CuInS2/TiO2 was prepared by a one-step solvothermal method.
• 2.5% CuInS2/TiO2 has the highest activity and keeps the activity stable.
• Heterojunction structure of sample promoted the separation of electrons and holes.

In this paper, p–n type CuInS2/TiO2 particles were prepared in ethylenediamine by the solvothermal method. The microstructural properties of the synthesized p–n type catalysts were characterized by X-ray diffraction (XRD) in order to confirm the existence of crystalline CuInS2 on the surface of TiO2, which was also confirmed by X-ray photoelectron spectroscopy (XPS). Transmission electron microscopy (TEM) images provided the detailed morphological properties about the CuInS2/TiO2 heterostructure. UV–vis diffuse reflectance spectroscopy (UV–vis DRS) was used to investigate the optical properties of the CuInS2/TiO2 particles. The DRS results indicated that both the p–n type structure and CuInS2 acting as a sensitizer can enhance significantly the absorption of UV and visible light. The photocatalytic activities of the CuInS2/TiO2 particles were evaluated by hydrogen evolution reactions using Xe-lamp irradiation as a simulated solar light source. The greatly enhanced photocatalytic activity of hydrogen evolution under simulated solar light is about ~7 fold higher than that of pure commercial TiO2 (Degussa P25).

The heterojunction structure of CuInS2/TiO2 promoted the efficiency of photoinduced charge carrier transfer and highly inherited the recombination of activated electrons and holes.Figure optionsDownload as PowerPoint slide