Synergistic plasmon resonance hybridization of iron‐dispersed <scp>MoO₃</scp>_−<i>x</i>/<scp>MXene</scp> for enhanced nitrogen photothermal reduction

Abstract Plasmonic photochemical N 2 fixation has received widespread attention owing to the attractive plasmonic enhancement effects in improving solar‐to‐NH 3 conversion efficiency. However, the weak N 2 adsorption affinity in metallic plasmonic photocatalysts and insurmountable interfacial barriers in metal–semiconductor plasmonic photocatalysts lead to rapid charge carrier recombination instead of participating in N 2 ‐to‐NH 3 conversion. Herein, a photothermal catalyst Fe‐dispersed MoO 3− x /MXene with synergistic plasmon resonance hybridization structure is fabricated for photothermal N 2 fixation. The hybrid plasmon resonance effects derived from MXene and MoO 3− x induce a strong optical response across the ultraviolet–visible‐near‐infrared range and generation of energetic charge carriers, and the induced photothermal effect further accelerates electron extraction, transport, and surface reaction kinetics. Moreover, the abundant oxygen vacancies and Fe sites can intensify the N 2 adsorption and donate the energetic electrons into the anti‐bonding system for the stimulative NH coupling process. A high NH 3 formation rate of 87.1 μmol g −1 h −1 is achieved under solar‐level illumination.