Photothermal-Assisted Photocatalytic Nitrogen Oxidation for Nitrate Synthesis over Plasmonic W₁₈O₄₉ Nanowires

Solar-driven nitrogen-to-nitrate conversion represents one of the most promising approaches for sustainable nitrogen fixation. However, this process faces significant challenges, primarily due to the limited utilization efficiency of the solar spectrum and inadequate nitrogen activation capability of conventional photocatalysts. To address these limitations, we develop plasmonic W₁₈O₄₉ nanowires with dual photothermal-photocatalytic functionality, which demonstrate remarkable performance with a nitrate production rate of 39.3 μmol g^-1 through direct N₂ photoconversion under 1 sun (100 mW cm^-2) illumination. Electrochemical characterization reveals that the synergistic photothermal effect significantly enhances charge carrier mobility while simultaneously optimizing the reaction energy barriers. Complementary in situ spectroscopic results and theoretical calculations provide mechanistic insights into the nitrogen adsorption and activation capabilities of the W₁₈O₄₉ catalyst. This work establishes a paradigm for solar energy utilization in photothermal-photocatalytic nitrogen fixation via plasmon-excited semiconductors.