Synchronizing carrier extraction and dielectric coupling in a hierarchical homometallic plasmonic catalyst for light-driven nitrate reduction

Abstract

Plasmonic photocatalysts present appealing opportunities for light energy conversion owing to the unique modes of light–matter interactions enabled by the localized surface plasmons. However, the energetic and dielectric mismatch between the plasmonic antenna and catalytic components typically brings about a distinct “energy filter” effect that substantially limits carrier extraction and energy conversion efficiencies. Through precise dielectric property alignment, we demonstrate in this study the design of an Au_L–S hierarchical homometallic plasmonic catalyst that exhibits exceptional energetic carrier extraction and multiscale dielectric coupling capabilities. Plasmon-induced non-thermal catalytic mechanisms including hot carrier injection and resonant polar induction orchestrate light-driven plasmonic catalytic performance for the nitrate reduction reaction by effectively facilitating the adsorption, polarization activation and chemical turnover of the non-polar reactant, leading to outstanding ammonia production and selectivity in both photoelectrochemical and photocatalytic measurements. This study demonstrates a new paradigm for plasmonic energetic carrier-driven photochemistry and provides crucial design principles for surface plasmon-mediated energy conversion systems.