Photoexcited Hot Electron Catalysis in Plasmon-Resonant Grating Structures with Platinum, Nickel, and Ruthenium Coatings

• DOI: 10.1021/acsami.3c16462
• Publication Date: 2024-04-02T13:36:34Z
• Authors: Indu Aravind; Yu Yun Wang; Yu Wang; Ruoxi Li; Zhi Cai; Bofan Zhao; Boxin Zhang; Sizhe Weng; Rifat Shahriar; Stephen B. Cronin
• Keywords: Photocurrent; Localized surface plasmon; Photoelectrochemistry

We report the electrochemical potential dependence of photocatalysis produced by hot electrons in plasmon-resonant grating structures. Here, corrugated metal surfaces with a period 520 nm are illuminated 785 wavelength laser light swept as function incident angle. At angles corresponding to excitation, we observe sharp peaks photocurrent and dips photoreflectance consistent conditions under which there is wavevector matching between spacing lines grating. In addition bare plasmonic surface (i.e., Au), catalytically inert, have measured structures thin layer Pt, Ru, Ni catalyst coatings. For Au grating, that remains relatively featureless over applied range from −0.8 +1.2 V vs NHE. Pt-coated peak around −0.3 NHE, three times larger than near complete suppression oxidation half-reaction, reflecting reducing nature Pt good hydrogen evolution reaction catalyst. The associated less noisy produces higher photocurrents due faster kinetics charge transfer) surface. enable us compare excitation bulk interband absorption simply rotating polarization while leaving all other parameters experiment fixed wavelength, potential, solution, sample surface, etc.). A 64X enhancement p-to-s polarized ratio) observed for compared 28X nickel-coated shows an increase hot-electron both reduction half-reactions. Similarly, Ru-coated gratings show half-reaction Plasmon-resonant factors 36X 15X ratio Ru gratings, respectively.