Construction of double S-scheme heterojunction in MIL-125(Ti)/ZnIn2S4/ZnS QDs to improve interfacial charge transfer and reduction potential for photocatalytic hydrogen production
Xiuxiu Huang, Shijian Zhang, Wenbin Ruan, Xinru Wang, Xinru Wang, Xiangyang Li, Shuangshuang Huai, Rui Cheng, Congliang Cheng, Ping Li, Jingjing Xia, Xiufang Wang, Xiufang Wang
Abstract
Photocatalytic water splitting has emerged as a viable strategy to address the prevailing environmental and energy dilemmas globally. Nonetheless, a significant obstacle to this sustainable technology lies in the inadequate separation and effective utilization of photogenerated electron-hole pairs within photocatalytic materials. Here, we constructed a novel double S-scheme MIL-125(Ti)/ZnIn 2 S 4 /ZnS quantum dots (MOF/ZIS/ZnS) heterojunction photocatalyst by facile hydrothermal and solvothermal method for photocatalytic hydrogen evolution (PHE). The optimal MOF/ZIS/ZnS photocatalyst demonstrates a remarkable hydrogen generation rate of 0.943 mmol·h −1 ·g −1 , and it is 10.84 times higher than pure ZIS (0.087 mmol·h −1 ·g −1 ). This significant boost in hydrogen production efficiency is due to the creation of a dual S-scheme heterojunction and an intrinsic electric field (IEF) among MOF, ZIS, and ZnS, which promotes charge transfer, reduces photogenerated carrier recombination, prolongs the lifespan of light-induced carriers and boosts the redox potential of photoexcited charges. This study provides fresh perspectives on the optimal design of dual S-scheme photocatalysts by harnessing energy band manipulation and IEF adjustments.