摘要
Maximizing ultrafast electron-transfer kinetics in semiconductor is pivotal but challenging for highefficiency solar-to-energy during the photocatalytic reaction process due to the intrinsic property of photocatalysts with low surface electron density.Herein,a model photocatalyst CdS@Mo is synthesized through a typical hydrothermal method for modulating the ultrafast electron-transfer to enhance the surface electron density.X-ray absorption fine spectra(XAFS)reveal that Mo is coordinated with S atoms to form a Mo-S_(6) configuration which is different from common MoS_(2) and Mo foil structures.Based on the femtosecond transient absorption spectra(fs-TAS),it is found that the formation of Mo-S6 configuration contributes to the fast decay of CdS signal and Mo-S_(6) signal reactivation,illustrating the ultrafast electron-transfer(∼2.2 ps)from CdS to Mo-S_(6) configuration,which achieves the enhanced electron density of photocatalyst surface.Finally,a holistic photocatalytic performance evaluation discloses that the growing of Mo-S_(6) configuration obviously improves the photocatalytic hydrogen evolution(PHE)effi-ciency of CdS from 28.5 to 47.5 mmol g^(-1)h^(-1)with a solar-to-hydrogen(STH)efficiency of 0.10%which is seldomly discussed in the system containing sacrificial agents.This work opens a new path to modulate the surface electron density by tuning the ultrafast electron-transfer for enhancing reaction efficiency in electron-density-dependent systems.
基金
The National Natural Science Foundation of China(Nos.22178291,22209135,22002123,and 22311530118)
the National Science Fund for the Distinguished Young Scholars(No.52325401)。
