Title: Peeking into the Femtosecond Hot-Carrier Dynamics Reveals Unexpected Mechanisms in Plasmonic Photocatalysis

Authors: Giulia Dall’Osto , Margherita Marsili, Mirko Vanzan, Daniele Toffoli, Mauro Stener, Stefano Corni, and Emanuele Coccia

DOI: https://doi.org/10.1021/jacs.3c12470

Date: 10/01/2024

Working Group: WG3

Grant Period: 2

Grant Period Goal (number): 2

Covered deliverables from the MoU (number): M42

Countries involved: Italy

Number of female/young/ITC coauthors: 3

Abstract: Plasmonic-driven photocatalysis may lead to reaction selectivity that cannot be otherwise achieved. A fundamental role is played by hot carriers, i.e., electrons and holes generated upon plasmonic decay within the metal nanostructure interacting with molecular species. Understanding the elusive microscopic mechanism behind such selectivity is a key step in the rational design of hot-carrier reactions. To accomplish that, we present state-of-the-art multiscale simulations, going beyond density functional theory, of hot-carrier injections for the rate-determining step of a photocatalytic reaction. We focus on carbon dioxide reduction, for which it was experimentally shown that the presence of a rhodium nanocube under illumination leads to the selective production of methane against carbon monoxide. We show that selectivity is due to a (predominantly) direct hole injection from rhodium to the reaction intermediate CHO. Unexpectedly, such an injection does not promote the selective reaction path by favoring proper bond breaking but rather by promoting bonding of the proper molecular fragment to the surface.