Dual Active Sites Enhanced Plasmon-Driven N₂ Photoreduction Over MoO_3-X Nanosheets Under Visible Excitation

Nitrogen photo-fixation used solar energy as a prospective way, has received more attention. In this study, a series of Ru-C/MoO_3-x photocatalysts with enhanced localized surface plasmon resonance effects for N₂ photo-fixation are developed, which not only construct abundant adsorption active sites but also promote the photocatalytic performances through reducing the N≡N bond dissociation activation energy. Notably, an additional LSPR peak at around 490 nm is observed in the UV-vis DRS spectra upon the introduction of the Ru element. Furthermore, increased N₂ adsorption capacity and more efficient carrier separation are obtained via the carbon decoration over the catalysts. Among these, the highest ammonia production rate over the Ru-C co-decorated photocatalyst achieves 864 µmol·g_cal ^-1·h^-1. Furthermore, a markedly apparent quantum efficiency exceeding 1.9% is achieved under visible light excitation at 420 nm, representing one of the highest values ever reported for photocatalytic N₂ fixation over metal oxide catalysts. Density functional theory calculations illustrate that the photocatalytic nitrogen reduction reaction follows the distal pathway, and the Ru/C composite activity sites in the samples can decrease the energy barrier in the rate-controlling step to further enhance the N₂ photoreduction.