Design Of Noble Metal-modified ZnIn₂S₄-based Photocatalysts And Their Synergistic Photocatalytic Hydrogen Production

Hydrogen production via photocatalytic water splitting would be a promising technique for the utilization of hydrogen energy and solar energy.ZnIn₂S₄(ZIS),as a visible light responsive ternary metal sulfide,is popular in many semiconductors.However,there are still some problems such as easy recombination of photogenerated carriers and narrow optical response range.With multidisciplinary integration,Surface Plasmon Resonance(SPR)of noble metal Nanoparticles(NPS)provides an ideal platform for the development of highly efficient photocatalysts with excellent visible light capture performance and catalytic activity.Based on this,this paper takes precious metal modified ZIS plasma photocatalyst as the research object,and studies its photocatalytic performance.The main research contents are as follows:The Au@Pt core-shell nanoparticle self-assembly structure was constructed on the surface of ZIS nanosheets,and a new type of Au@Pt/ZnIn₂S₄ photocatalyst was successfully synthesized,in which the host nanoparticle was composed of Pt nanoparticle coated with plasma Au nanoparticle.Based on the SPR resonance excitation of the self-assembled plasmonic Au@Pt nanoparticles on three-dimensional ZIS microspheres,the catalyst has excellent photolysis performance of water for hydrogen production under visible light(?420 nm).The H₂ production amount and rate over Au16@Pt/ZIS can reach 41747?mol·g^-1 and 4174.7?mol·g^-1·h^-1 under visible light,about 10 times higher than those of ZIS,respectively.Therefore,the self-assembly of core-shell nanoparticles and the introduction of ZIS can significantly improve the photocatalytic performance of plasma metal nanoparticles.The experimental results and FDTD simulation results confirm that the plasma c oupling effect of Au@Pt self-assembled structure can generate strong electromagnetic field on the surface of ZIS,which further extends the light absorption to the visibor-near-infrared region,and at the same time increases the generation rate of Au plasma thermoelectrons and ZIS photogenerated electrons.In addition,the Pt shell plays a role of electron absorption,which enables the effective separation of electrons and holes in Au nanoparticles and ZIS,thus further increasing the precipitation of H₂,and finally makes Au@Pt/ZIS have excellent photocatalytic hydrogen production ability.The Au@ZIS heterocore-shell Nanocrystals(NCs)were prepared by non-epitaxial growth method combined with cation exchange reaction.Then,the NCs were anchoring on two-dimensional Ti₃C₂T_x thin sheets with few or single layers to construct the composite photocatalyst of Au@ZIS/Ti₃C₂T_x.Au26@ZIS/Ti₃C₂T_xcatalyst has a better photocatalytic hydrogen production performance under visible light due to the local electric field enhancement effect excited by SPR.After 4 h visible light irradiation,the hydrogen production of Au26@ZIS-2/Ti₃C₂T_x is 11.78umol·cm^-2,which is significantly higher than that of Au26/Ti₃C₂T_x(7.09 umol·cm^-2)and ZIS/Ti₃C₂T_x(5.64 umol·cm^-2).The experimental results show that Au@ZIS heterogeneous coreshell NCs promote the generation of more photogenerated carriers in Au NPs and ZIS NCs under the effect of local electric field enhancement,Au@ZIS NCs of the core-shell structure and promote effective heterogeneous contact interface electronic-hole on the separation of and under the action of Ti₃C₂T_x rapid separation and migration,thus making Au@ZIS/Ti₃C₂T_x has the very good photoelectric catalyzed hydrogen production performance.