Systhesis And Photocatalystic Hydrogen Production Of Visible Light Responsive Mental Sulfides Based Photocatalysts

With the rapid development of society and economy,there is a growing need to find alternatives to traditional fossil fuels.Solar and hydrogen energy as cheap and pollution-free renewable sources can effectively alleviate the energy crisis.Photocatalytic hydrogen production has become one of the current research hotpots due to its potential of environmental protection and energy saving potential.The conversion between solar energy and chemical energy by splitting water into hydrogen energy driven by solar energy is considered as a promising technology.In this paper,a series of photocatalytic composites were designed and constructed with metal sulfides as the main research objects,which not only optimizes the visible light response of single semiconductor,but also improves the separation and transfer of interfacial photogenerated electron-hole pairs,so that them have high catalytic activity.The specific research content is divided into the following four aspects:1.In this chapter,Zn_xCd_1-xS photocatalysts synthesized by solvothermal method which have small and uniform particle size through using zinc acetate,cadmium acetate and thioacetamide as raw materials.Explore the solid solution products with different energy band structures by changing the different molar ratios of zinc and cadmium.All the Zn_xCd_1-xS samples have great increase performance in hydrogen production compared with single CdS and Zn S.Among of them,ZCS-3 exhibits optimal photocatalytic activity at a rate of 2.19 mmol g^-1 h^-1.Finally,the cycling experiment of water splitting test found that the Zn_xCd_1-xS photocatalyst has good cycling stability.2.The UiO-66/CdIn₂S₄ heterojunction composites were constructed by using the metal-organic framework UiO-66 as the carrier and encapsulated by CdIn₂S₄nanosheets through oil bath in this part.The intimate contact interfaces and the matching energy band structure between the two semiconductors are favorable for the rapid transfer of photoelectric charges,which significantly promote the generation of hydrogen.Under the excitation of visible light,the best photocatalytic performance of hydrogen is obtained when the weight content of UiO-66 is 25%.This scheme provides a new idea for the research and application of UiO-66 as co-catalyst.3.In this chapter,the core-shell SnS₂/CdIn₂S₄ was synthesized by hydrothermal method through in situ synthesis of SnS₂ nanosheets on the surface of CdIn₂S₄nanoflower.After a variety of characterization methods of SnS₂/CdIn₂S₄photocatalysts and water splitting test,it was proved that the composite material coated with SnS₂ showed excellent hydrogen production performance and high resistance of recombination of photogenerated carriers.When the loading of SnS₂reached 11%wt,the hydrogen production activity reached 345.2μmol/g/h.4.The Ag₃PO₄/CdS photocatalysts are prepared by using a simple solvothermal method to synthesize CdS nanorods at first,and then synthesizing small sized Ag₃PO₄nanoparticles on them by deposition method.The visible light absorption intensity is greatly improved thanks to the Z-scheme heterojunction formed by Ag₃PO₄ and CdS,which greatly improves the activity of photocatalytic hydrogen evolution.When Ag₃PO₄mass loading up to four percent,the photocatalytic performance is strongest with perfect stability in the cycling test.