In situ growth of Cu⁰-modified oxynitride for optimized photocatalytic nitric oxide oxidation

Photocatalysis technology provides a promising and green strategy for the abatement of low-concentration NO pollutants in the ambient air. An earthworm-like oxynitride decorated with in situ grown Cu nanoparticles is synthesized through the ammonolysis of the CuO-doped ZnGa₂O₄ spinel. The optimized morphology promoted the exposure of active sites and expanded the reaction interface for efficient NO adsorption and photocatalytic conversion. The decoration of Cu⁰ and N^3- doping enhanced the light absorption and imparted a tunable energy band structure. The strong interactions between Cu⁰ and the Ga_1-xZn_xN_1-yO_y interface maximize the utilizing photo-induced charge by facilitating the transfer and inhibiting the recombination of the charge carrier. The strong adsorption of H₂O and NO on Cu⁰ and internal electric field of Cu⁰-Ga_1-xZn_xN_1-yO_y junction contribute to the high selectivity of NO. This study provides a new perspective on the design of visible-light-driven photocatalysts with Schottky junction for environmental remediation.