Increasing reactivity of plasmonic hot holes by a trapping strategy

Plasmonic photocatalysis has emerged as a promising solution for global energy crisis and environment pollution by facilitating wide ranging chemical transformations using photons in a broad region of solar spectrum. Despite numerous successful examples on improvement of electron-driven photochemistry, effective utilization of plasmonic hot holes is a long-standing challenge due to their ultrafast relaxation and short lifetime. Herein, we report that the reactivity of plasmonic hot holes can be greatly enhanced by a novel hot hole trapping strategy. We demonstrate a new concept of a metal-adsorbate interfacial structure that can be in situ constructed on gold (Au) surface in the presence of molecular hydrogen (H2) under plasmonic excitation, where the key is to employ an electron-filled antibonding state hybridized by H1s and Au5d as a localized trap to improve utilization efficiency of plasmonic hot holes. This interfacial structure is evidenced by light-induced H2 spillover and d-band model analysis. The prolonged lifetime and preserved oxidation power of plasmonic hot holes was evidenced by superior photocatalytic activity for methylene blue (MB) degradation in the presence of H2 which was accelerated by over 5 times. In addition, FTIR coupled with CO molecular probe reveals that the physical location of hole trapping are low coordinated positions sites on Au nanoparticles. These findings could provide an innovative pathway to increase utilization efficiency of hot holes for visible-light-driven photocatalysis applications.

Automated summary

The research introduces a novel hot hole trapping strategy to enhance the reactivity of plasmonic hot holes, demonstrating the construction of a metal-adsorbate interfacial structure on a gold surface under plasmonic excitation. This interfacial structure effectively improves the utilization efficiency of plasmonic hot holes by utilizing a localized trap hybridized by H1s and Au5d, resulting in prolonged lifetime and preserved oxidation power.