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Photocatalytic water splitting for hydrogen evolution by utilizing the solar energy is a significant research topic. With more and more severe energy crisis and environmental problems facing humanity, developing renewable and clean energy has become an urgent task for the future development of mankind. Hydrogen may be one of the ideal new energy because of its advantages such as clean, renewable, combustion value is high and transportability. Photocatalytic water splitting for hydrogen evolution is the cleanest, cheapest and most sustainable way to get hydrogen. In this thesis, the modification of ZnS semiconductor photocatalytic materials for visible-light response was studied, we synthesized In2S3-ZnS and NiS-In2S3-ZnS solid solution, X-ray diffraction (XRD), scanning electron microscope (SEM), ultraviolet visible diffuse reflectance spectra (UV-Vis), inductive coupled plasma emission spectrometer (ICP) were employed to characterize the photocatalyst. Moreover, the photocatalytic activity of the obtained photocatalysts was evaluated based on the photocatalytic H2 evolution under simulated sunlight irradiation.A series of In2S3-ZnS with different compositions (expressed as In2xZn3(1-X)S3) were synthesized by a Solvothermal method. The characterization of photocatalyst confirmed that:with the introduction of In3+, the particle size of the photocatalyst was significantly smaller and the specific surface was increased, the crystal structures of ZnS were gradually transform from cubic to hexagonal structure and the diffraction peaks shifted to lower angles which indicated the crystals obtained should be solid solutions, the introduction of In3+ can also reduce the band gap of ZnS semiconductor, the absorption edge shifts monotonically to longer wavelengths as the amount of In increases. Through a series of photocatalytic produce hydrogen experiments, the effect of preparation methods, material ratio, the concentration of photocatalyst, and sacrificial reagent types were investigated in detail. The best condition of the photocatalytic H2 evolution activity was obtained as follows:In2S3-ZnS prepared through hydrothermal method using Zn(NO3)2·6H2O, In(NO3)3·4.5H2O, thiourea and ultra-pure water as raw material, reaction at 160℃for 48h, the composition of the photocatalysts was In0.14Zn2.79S3, the concentration of photocatalyst was 0.8g/L, when glucose was used as the sacrificial reagent, the best concentration was 0.08M, in this condition, the best photocatalytic H2 evolution activity can reach 503μmol/h-gcat, when 0.35M Na2S-0.25M K2SO3 was used as the sacrificial reagent, the best photocatalytic H2 evolution activity can reach 1.4mmol/h-gcat.NiS-In2S3-ZnS was synthesized by add Ni2+ into In2S3-ZnS (expressed as Zn2.79In0.14NixS3+x), The characterization of photocatalyst confirmed that:the addition of Ni2+ could further transform the crystal structures of ZnS from sphalerite to wurtzite, strengthen the nanoporous structure of the photocatalyst and increasing its specific surface, its can also make the absorption edge of ZnS further shifts to longer wavelengths. The result of photocatalytic produce hydrogen experiments showed that: the composition of the photocatalysts was Zn2.79In0.14Ni0.013S3.013, the best concentration of photocatalyst was 0.6g/L, when glucose was used as the sacrificial reagent, the best concentration was 0.08M, in this condition, the best photocatalytic H2 evolution activity can reach 604μmol/h·gcat, when 0.35M Na2S-0.25M K2SO3 was used as the sacrificial reagent, the best photocatalytic H2 evolution activity can reach 1.79mmol/h-gcat.A typical cycle experiment showed that:when glucose was used as the sacrificial reagent, photocatalytic activity was decreased with the extension of reaction time, when Na2S-K2SO3 was used as the sacrificial reagent, after irradiate for more than 20h, the photocatalytic H2 evolution activity almost showed no decline, indicating that the photocatalyst has considerable stability.
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