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

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.