Regulating Adsorption Activation of Reactants by Bi‐Cl Synergistic Sites for Promoting Photocatalytic NO Deep Oxidation

Abstract Photocatalytic nitrogen oxides (NO_x) oxidation highly depends on the adsorption activation mode of pollutant molecules and the efficient generation of reactive oxygen species (ROS). Previous research underscores the construction of reactive active site synergistic mechanisms for enhancing reactant adsorption and activation. Herein, Bi‐metal is introduced onto the halogen intercalation by synergistically utilizing the strong electronegativity of Cl atoms and oxygen vacancy sites to promote directional charge transfer, forming an electronically localized layer of Cl and unsaturation‐charged Bi sites, which can change the activation mode of reactants and promote ROS formation. The OVs‐Bi₄TaO₈Cl/Bi with Bi–Cl synergistic sites immobilized on ceramic foam exhibited nitric oxide (NO) conversion efficiency of 89.0% with great stability (82.1% after 200 min) and extremely lowed toxic nitrogen dioxide (NO₂) conversion (0.1%). The OVs‐Bi₄TaO₈Cl/Bi can convert NO into nitrosyl anion (NO⁻) during the adsorption activation process, thus effectively oxidizing it into the nitrate (NO₃⁻) with NO₂ inhibition. This study provides new insights into the development of effective photocatalysts with synergistic active sites for air pollutant purification.