Hydrogen evolution with hot electrons on a plasmonic-molecular catalyst hybrid system

Abstract

Plasmonic systems convert light into electrical charges and heat, mediating catalytic transformations. However, there is ongoing controversy regarding the involvement of hot carriers in the catalytic process. In this study, we demonstrate the direct utilisation of plasmon hot electrons in the hydrogen evolution reaction with visible light. We intentionally assemble a plasmonic nanohybrid system comprising NiO/Au/[Co(1,10-Phenanthrolin-5-amine)2(H2O)2], which is unstable at water thermolysis temperatures. This assembly limits the plasmon thermal contribution while ensuring that hot carriers are the primary contributors to the catalytic process. By combining photoelectrocatalysis with advanced in situ spectroscopies, we can substantiate a reaction mechanism in which plasmon-induced hot electrons play a crucial role. These plasmonic hot electrons are directed into phenanthroline ligands, facilitating the rapid, concerted proton-electron transfer steps essential for hydrogen generation. The catalytic response to light modulation aligns with the distinctive profile of a hot carrier-mediated process, featuring a positive, though non-essential, heat contribution.

Noble Metal Plasmon–Molecular Catalyst Hybrids for Renewable Energy Relevant Small Molecule Activation

“…Recently, Sáet al directly utilized plasmonic hot electrons generated with visible light irradiation for catalytic HER. 101 Here, the focus was to distinguish between photothermal and hot-carrier mechanisms in plasmonic-driven catalysis. To ensure that the hot carriers can act as the major contributors to the catalytic process, the plasmonic nanohybrid system NiO/Au/[Co(1,10-phenanthrolin-5-amine) 2 (H 2 O) 2 ] was deliberately assembled to limit the plasmon thermal contribution.…”

“…Recently, Sá et al directly utilized plasmonic hot electrons generated with visible light irradiation for catalytic HER . Here, the focus was to distinguish between photothermal and hot-carrier mechanisms in plasmonic-driven catalysis.…”

“…Schematic representation of the catalytic cycle leading to H 2 evolution with a NiO/Au/[Co(1,10-phenanthrolin-5-amine) 2 (H 2 O) 2 ] plasmonic nanohybrid system. Recreated from ref . Available under a CC BY 4.0 DEED License.…”

Origin of Macroscopic Observables of Strongly Coupled Metal Nanoparticle–Molecule Systems from Microscopic Electronic Properties

“…An interesting avenue of research is the excited state dynamics and energy transfer processes between metal NPs and adsorbed molecules under various conditions. − In this context, the strong coupling regime is especially promising, since the initial eigenstates become thoroughly mixed, which leads to the formation of new energy states and potentially favorable electron transition possibilities . These changes of the electronic landscape yield modifications of reaction pathways, − allowing for modified chemistry, catalytic applications, or enhanced selectivity .…”