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Photocatalysts can absorb light and activate molecular O 2 under mild conditions, but the generation of unsuitable reactive oxygen species often limits their use in synthesizing fine chemicals. To address this issue, we disperse 1 wt% copper on tungsten trioxide (WO 3 ) support to create an efficient catalyst for selective oxidative coupling of aromatic amines to imines under sunlight irradiation at room temperature. Copper consists of a metallic copper core and an oxide shell. Experimental and density functional theory calculations have confirmed that Cu 2 O is the primary activation site. Under λ < 475 nm, the light excites electrons of the valence bands in Cu 2 O and WO 3 , which activate O 2 to superoxide radical • O 2 - . Then rapidly transforms into oxygen adatoms ( • O) and oxygen anion radicals ( • O - ) species on the surface of Cu 2 O. Simultaneously, it is captured by holes in the WO 3 valence band to generate singlet oxygen ( 1 O 2 ). • O bind to 1 O 2 promoting the coupling reaction of amines. When λ > 475 nm, intense light absorption due to the localized surface plasmon resonance excites numerous electrons in Cu to promote the oxidative coupling with the adsorbed O 2 . This study presents a promising approach towards the design of high-performance photocatalysts for solar energy conversion and environmentally-friendly oxidative organic synthesis., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)