Study On The Structure-activity Relationship Of Sulfide Nanomaterials And Their Photocatalytic (electrocatalytic) Propertie

Due to current social trends,there is a need for clean energy to address the two major social issues of the current energy crisis and environmental pollution.Hydrogen energy is one of the most ideal new green energy sources due to its environmental friendliness,cleanliness,high energy conversion rate,and advantages such as achieving zero carbon emissions and no pollution throughout the process.The photo（electro）catalytic water decomposition technology of hydrogen production through solar energy is expected to solve the above-mentioned problems.Sulfide semiconductor nanomaterials have advantages such as a narrow bandgap,easy synthesis,and controllable surface structure.Compared with traditional photocatalysts such as Ti O₂,they can absorb and utilize more light in the visible spectrum range.Therefore,sulfide semiconductor nanomaterials have great potential in the field of photo（electro）catalysis.In this study,CdS nanoparticles,nanosheets,and Bi₂S₃nanorods were selected as research objects to systematically investigate the structure-performance relationship of semiconductor catalysts in photo（electro）catalytic reaction processes,summarize the impact of structure on performance,and propose the photo（electro）catalytic mechanism of highly efficient reaction systems.The specific research content is as follows.1.CdS hollow nanospheres were successfully prepared by hydrothermal method using Si O₂nanoparticles as templates.In order to improve the photocatalytic hydrogen production performance of CdS,different amounts of Ag₂S nanoparticles were ion-exchanged into CdS hollow nanospheres,and the effects of different ion-exchange concentrations on the photocatalytic hydrogen production performance were studied.Among them,the CdS hollow nanospheres with an ion exchange molar ratio of 30%for Ag₂S had the highest hydrogen production rate,reaching 1551.8μmol/g,which was 26times that of pure CdS hollow nanospheres（58.9μmol/g）,showing better photocatalytic performance.The composite of Ag₂S nanoparticles and CdS hollow nanospheres enhanced the utilization of light energy,resulting in more efficient generation of photoinduced charges.Meanwhile,the heterojunction structure constructed by the hollow nanospheres could promote the rapid separation and transfer of charges,enhancing the photocatalytic hydrogen production performance of water splitting.2.CdS nanosheets were successfully prepared by organic thermal solvent method,and then further loaded with Zn In₂S₄nanosheets via oil-bath method to form a CdS/Zn In₂S₄nanosheet composite structure.The effect of different substrate addition amounts on the performance of the composite was studied,and the highest photocurrent density of the sheet-like composite material was obtained at 4.5μA/cm²when the CdS substrate addition amount was 120 mg.The nanosheet composite structure of CdS and Zn In₂S₄is beneficial to the separation and transfer of electrons and holes,improving the photocatalytic performance of the composite material.3.Bi₂S₃/TiO₂nanorod composites were prepared by self-assembled hydrothermal method,which were used as photoanodes for photoelectrocatalytic hydrogen production by water splitting.The effect of different reaction temperatures on the photoelectrochemical performance was studied,and the Bi₂S₃/Ti O₂photoanode with rod-like crosslinked heterojunction structure synthesized at 160^oC exhibited a photocurrent density of 0.2 m A/cm²,which was 20 times that of the pure Ti O₂nanorod photoanode.The three-dimensional nanorod crosslinked structure accelerated the transfer and separation abilities of photoinduced charges,and the 3D crosslinked structure of Bi₂S₃/Ti O₂had a larger specific surface area,which could enhance the utilization of light energy and provide more active sites for the reaction.