In Situ Investigation of Ultrafast Dynamics of Hot Electron-Driven Photocatalysis in Plasmon-Resonant Grating Structures

• DOI: 10.1021/jacs.1c12069
• Publication Date: 2022-02-21T19:42:25Z
• Authors: Yu Wang; Yi Wang; Indu Aravind; Zhi Cai; Lang Shen; Boxin Zhang; Bo Wang; Jihan Chen; Bofan Zhao; Haotian Shi; Jahan M. Dawlaty; Stephen B. Cronin
• Keywords: Laser linewidth; Photocurrent

Understanding the relaxation and injection dynamics of hot electrons is crucial to utilizing them in photocatalytic applications. While most studies have focused on carrier at metal/semiconductor interfaces, we study situ direct electron from metal adsorbates. Here, report a electron-driven hydrogen evolution reaction (HER) by exciting localized surface plasmon resonance (LSPR) Au grating photoelectrodes. In ultrafast transient absorption (TA) measurements show depletion peak resulting electrons. When sample immersed solution under -1 V applied potential, extracted electron-phonon interaction time decreases 0.94 0.67 ps because additional energy dissipation channels. The LSPR TA signal redshifted with delay charge transfer subsequent change dielectric constant nearby solution. Plateau-like photocurrent peaks appear when 266 nm linewidth p-polarized (on resonance) light, accompanied similar profile measured absorptance. Double measurement are observed irradiating 300 grating. enhancement factor (i.e., rate) 15.6× between s-polarized light for 4.4× Finite-difference domain (FDTD) simulations two resonant modes both structures, corresponding dipolar metal/fused silica metal/water interfaces. To our knowledge, this first work which LSPR-induced photochemistry photoexcited studied same structure without