Plasmon-Induced Ultrafast Interfacial Charge Transfer for Enhanced Photocatalytic Hydrogen Evolution

Abstract

The localized surface plasmon resonance (LSPR) effect of precious metals plays a pivotal role in photocatalytic H₂ evolution, where plasmon-generated hot electrons are efficiently injected into the photocatalytic system, profoundly modulating interfacial electron transfer dynamics. Regrettably, the specific impact of the LSPR effect of precious metals on the ultrafast interfacial charge transfer and its kinetic characteristics remains inadequately explored in photocatalystic systems. To address these knowledge gaps, Au nanoparticles are incorporated into the CdS/ReS_x photocatalyst to comprehensively investigate the LSPR-induced ultrafast interfacial charge transfer, ultimately boosting photocatalytic H₂ production activity. The experimental results reveal that the developed CdS/Au_0.5@ReS_x photocatalyst achieves a notable H₂-production activity with a rate of 8.6 mmol g^–1 h^–1 (AQE = 35.9%), which is evidently higher than that of CdS/Au (1.8 mmol g^–1 h^–1) and CdS/ReS_x (4.0 mmol g^–1 h^–1). In situ XAFS and fs-TAS characterizations confirm that the Au LSPR effect generates electron-deficient Au^δ+ species and contracts Au–S bond lengths, dramatically accelerating electron transfer in the Au@ReS_x cocatalyst. This plasmon-induced ultrafast charge transfer mechanism enables efficient photogenerated electron migration in the CdS/Au@ReS_x system, promoting interfacial charge dynamics for exceptional photocatalytic H₂ evolution performance. The findings offer a new understanding of charge transfer mechanisms enabled by LSPR effects and create a blueprint for engineering next-generation plasmonic photocatalysts.