Synergistic plasmon resonance hybridization of iron-dispersed MoO3−x/MXene for enhanced nitrogen photothermal reduction

Abstract

Plasmonic photochemical N₂ fixation has received widespread attention owing to the attractive plasmonic enhancement effects in improving solar-to-NH₃ conversion efficiency. However, the weak N₂ 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 N₂-to-NH₃ conversion. Herein, a photothermal catalyst Fe-dispersed MoO_3−x/MXene with synergistic plasmon resonance hybridization structure is fabricated for photothermal N₂ 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 N₂ adsorption and donate the energetic electrons into the anti-bonding system for the stimulative NH coupling process. A high NH₃ formation rate of 87.1 μmol g⁻¹ h⁻¹ is achieved under solar-level illumination.