Preparation Of One-dimensional Cadmium Sulfide Photocatalyst And Hydrogen Production Research

Hydrogen can be considered as the most suitable new clean energy carrier for development to replace the increasing pressure of fossil fuels on environmental issues increase yearly.One of the hopeful approaches to obtain H2 is solar-driven water-splitting reaction that can convert solar energy to hydrogen ene rgy with less additional pollution.Loading noble metals onto the surfaces of photocatalysts can indeed achieve the high photocatalytic H2 by effectively promoting the separation of photoexcited holes and electrons.However,a broader range of applications is limited because of the low abundance in earth and thus high cost.In this thesis,PAN nanofiber precursors containing Cd ions are synthesized by electrospinning,and the one-dimensional nanophotocatalyst composed of Cd S and carbon,reacted by solvothermal and pyrolysis processes.The potential of high-efficiency photocatalytic reduction of H2 was studied in the visible light(? ? 420 nm)without precious metal promoters.Firstly,the thesis is to systematically study the electrospinning process,solvothermal process and heat treatment process for relatio nship to sample morphology,performance and photocatalytic H2 production activity.A series of Cd S/C one-dimensional nanowire composite photocatalysts were synthesized by pyrolysis in a nitrogen atmosphere.The promotion effect on the photocatalytic H2 production process was explored.For the synthesis process,the preparation method of nanofibers,Cd S composite method and modification method were determined,and the internal relationship between morphology and catalytic performance was studied.Finally,under the experimental conditions that the material is not added with noble metal promoter under visible light,the performance test of photocatalytic water splitting to produce H2 is conducted to select the best performance sample.Then,we found the structure-activity relationship of composite fiber photocatalyst.The heat treatment atmosphere was changed,and the sample was oxidized in air to obtain carbon and Cd S composite photocatalyst O-Cd S / C with a structure of one-dimensional hollow nanotubes.The experimental results determined that the electrons move from Cd-S bond to Cd-O bond in the sample,which provided strong support for the mechanism analysis of the photocatalyti c activity enhancement.O-Cd S/C also has high photocatalytic H2 production activity in the ultraviolet region,and carbon fiber can replace part of the function of the co-catalyst.The carbon effectively uses its excellent electrical conductivity and plays a major role in improving photocurrent.The capacity of carriers to participate in the photocatalytic H2 production reaction is improved by increasing the number of photogenerated carriers,separation efficiency,migration capacity,and reducing migration resistance.