Activating plasmonic catalysis through light-mediated steady-state spin modulation

Light-mediated electronic spin modulation possesses intriguing potentials for photochemistry, enabling on-demand customization of catalysts towards distinct reactions and catalytic requirements. However, the significant photobleaching of the transient spin transitions as well as their temporal mismatch with slower chemical reaction dynamics substantially hinders its applicability. Herein, we demonstrate light-driven steady-state and on-demand catalyst spin modulation that effectively activates plasmonic catalysis. The rapidly oscillating plasmonic electromagnetic near-field spin-polarizes a low-spin CoFe₂O₄ catalyst and overcomes the photobleaching to produce stable high-spin states with astounding spin lifetimes >60 μs. The high-spin plasmonic catalyst effectively balances the tradeoff between spin polarization and carrier dynamics. For benchmark light-driven nitrate reduction catalysis, it achieves substantial photo-enhancement in ammonia production rate and selectivity as well as photocatalytic performance driven by sunlight, benefiting from polarization activation of nitrate reactant and preferential reaction pathway modulation. The highly generalized light-mediated strategy opens intriguing new avenues for on-demand and steady-state electronic spin engineering with profound implications for distinct disciplines.