Light-emitting diode visible-light-driven photocatalytic redox reactions in nitrogen oxide removal using β-Bi₂O₃/Bi/g-C₃N₄ prepared by one-step in situ thermal reduction synthesis

Traditional photocatalytic oxidation of nitrogen oxide (NO) may cause the more toxic NO₂ generation after longtime reaction, and even the ideal final production nitrate may also inevitably cause the poisoning of photocatalysts. Thus, utilizing photocatalytic reduction to remove NO into N₂ should be considered more practical but is still challenging currently. Herein, a novel S-scheme β-Bi₂O₃/Bi/g-C₃N₄ heterojunction photocatalyst is developed via a one-step in situ thermal reduction method. The photocatalytic degradation efficiency over this S-scheme photocatalyst exhibits around 88.7% degradation rate for NO with little NO₂ generation under light-emitting diode light irradiation, which is significantly higher than that of the pristine g-C₃N₄ (60%). Interestingly, both reduction of NO into N₂ and oxidation of NO into NO₃⁻ exist synchronously in the system. The increased degradation efficiency and the efficient reduction pathway occurring should be ascribed to the enhanced generation, separation, and transfer of the photogenerated carriers through the Bi-bridge S-scheme heterojunction. This study has provided a new route for regulating the photocatalytic reaction pathway for NO removal through a simple synthesis method. Copyright © 2022 The Authors. Advanced Energy and Sustainability Research published by Wiley-VCH GmbH.