Photoelectrochemical (PEC) nitrogen fixation has opened up new possibilities for the production of ammonia from water and air under mild conditions, but this process is confronted by the inherent challenges associated with theoretical and experimental works, limiting the efficiency of the nitrogen reduction reaction. Herein, we report for the first time a novel and efficient photoelectrocatalytic system, which has been prepared by assembling plasmonic Au nanoparticles with Fe-doped W18O49 nanorods (denoted as WOF-Au). (i) The introduction of exotic Fe atoms into nonstoichiometric W18O49 can eliminate bulk defects of the W18O49 host, which resulted in narrowing bandgap energy and facilitating electron-hole separation and transportation. (ii) Meanwhile, Au nanoparticles combined with a semiconductor induce the localized surface plasmon resonance and generate energetic (hot) electrons, increasing electron density on W18O49 nanorods. Consequently, this plasmonic WOF-Au system shows an NH3 production yield of 9.82 μg h-1 cm-2 at -0.65 V versus Ag/AgCl, which is ∼2.5-folds higher than that of the WOF (without Au loading), as well as very high stability, and no NH3 formation was found for the bare W18O49 (WO). This high activity can be associated with the synergistic effects between the Fe dopant and plasmonic Au NPs on the host semiconductor W18O49. This work can bring some insights into the target-directed design of efficient plasmonic hybrid systems for N2 fixation and artificial photocatalysis.
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