Abstract
Rapid charge carrier recombination rate and insufficient light harvesting capacity are two dominat-ing drawbacks encountered in zinc indium sulfide(Znln2S4)for photocatalytic applications.Herein,a chemical reduction method was performed to combine bimetallic Ag-Pd alloy nanoparticles(NPs)with spherical-like Znln2S4(ZIS).By optimizing Ag:Pd molar ratio and overall loading amount,the optimal Ag0.25Pd0.75-ZIS sample exhibited a maximum H2 evolution rate(125.4 pmol/h)under visible light,which was higher than that of ZIS,Ag-ZIS and Pd-ZIS.The loading of Ag NPs contribution to PHE reaction by its plasmonic effect was negligible compared to that of Pd loading(Schottky effect).The apparent quan-tum yield(AQY)values over Ag0.25Pd0.75-ZIS sample could reach up to 18.3％at 400 nm and 15.8％at 420 nm.The enhanced activity for photocatalytic hydrogen evolution(PHE)over Ag0.25Pd0.75-ZIS sample was mainly due to the bimetallic synergistic effect that presented as follows.Firstly,the plasmon hy-bridization by loading Ag-Pd bimetallic alloy can significantly increase light harvesting capacity of ZIS.Secondly,the optimal Schottky barrier height formed between Ag-Pd alloy and ZIS interface was benefi-cial for prolonging electron-hole pair lifetimes,promoting charge carrier separation and thus facilitating PHE efficiency.Density functional theory(DFT)analysis indicated that the adsorption energy of H*over Pd0.75Ag0.25 alloy was very close to zero and thus theoretically possessed the highest activity for H2 evo-lution,which is in line with experimental results.Combined theoretical calculation with experimental results,a reasonable photocatalytic mechanism was proposed and verified.
基金项目
国家自然科学基金(51902282)
Qinglan Project of Jiangsu of China,Postgraduate Research&Practice Innovation Program of Yancheng Institute of Technology(KYCX21_X2005)
Open Fund of Key Laboratory for Advanced Technology in Envi-ronmental Protection of Jiangsu Province,Natural Science Foundation (BK20211361)
Open Fund of Key Laboratory for Advanced Technology in Envi-ronmental Protection of Jiangsu Province,Natural Science Foundation (BX2021054)
College Natural Science Research Project of Jiangsu Province(20KJA430004)
万方数据