Dual-Plasmon Resonance Coupling Promoting Directional Photosynthesis of Nitrate from Air

Photocatalysis, particularly plasmon-mediated photocatalysis, offers a green and sustainable approach for direct nitrogen oxidation into nitrate under ambient conditions. However, the unsatisfactory photocatalytic efficiency caused by the limited localized electromagnetic field enhancement and short hot carrier lifetime of traditional plasmonic catalysts is a stumbling block to the large-scale application of plasmon photocatalytic technology. Herein, we design and demonstrate the dual-plasmonic heterojunction (Bi/Cs_xWO₃) achieves efficient and selective photocatalytic N₂ oxidation. The yield of NO₃⁻ over Bi/Cs_xWO₃ (694.32 μg g⁻¹ h⁻¹) are 2.4 times that over Cs_xWO₃ (292.12 μg g⁻¹ h⁻¹) under full-spectrum irradiation. The surface dual-plasmon resonance coupling effect generates a surge of localized electromagnetic field intensity to boost the formation efficiency and delay the self-thermalization of energetic hot carriers. Ultimately, electrons participate in the formation of ⋅O₂⁻, while holes involve in the generation of ⋅OH and the activation of N₂. The synergistic effect of multiple reactive oxygen species drives the direct photosynthesis of NO₃⁻, which achieves the overall-utilization of photoexcited electrons and holes in photocatalytic reaction. The concept that the dual-plasmon resonance coupling effect facilitates the directional overall-utilization of photoexcited carriers will pave a new way for the rational design of efficient photocatalytic systems.