Abstract: Landau damping of surface plasmons generates hot electron-hole pairs, which carry an initial energy equal to the plasmon quanta before relaxation. These hot carriers hold the promise for nonthermal pathways for photoelectric conversion and photocatalytic reactions. Despite decades of experimental and theoretical efforts, the mechanism and the precise role of the plasmonic hot carriers have not been well understood. Here, I will report our latest results on plasmon induced hot carrier transfer and photochemistry at metal nanoparticle (MNP) surfaces and interfaces. In the first part, the hot electrons and holes at the MNP@TiO2 interface were found to offer two competing and tunable channels for nonthermal charge transfer [1,2]. In the second part, we present a model of plasmonic photocatalysis based on the Anderson-Newns model of electron-vibration coupling [3]. Plasmonic hot carriers are found to induce vibrational heating of molecular bond and significantly promote photodissociation [4]. We discuss the potential applications of these findings.
References:
1. Jie Ma and Shiwu Gao, Plasmon induced electron-hole separations at the Ag/TiO2(110) interface, ACS Nano 13, 13658-13667 (2019).
2. Jie Ma, Xindan Zhang, and Shiwu Gao, Tunable electron and hole injection channels at the Al/TiO2 interface, Nanoscale 13, 14073-14080, (2021); 15, 1754-1762 (2023), ibid.
3. Shengxiang Wu, Yu Chen, and Shiwu Gao, Plasmonic photocatalysis with nonthermalized hot carriers, Phys. Rev. Lett. 129, 086801 (2022).
4. Yu Chen and Shiwu Gao, to be published (2024).