Subsurface Ce dopants in Bi₂MoO₆ monolayers as promoters for photocatalytic C‐N coupling reaction

Understanding the role of subsurface dopants in photocatalysis is still highly challenging, although doping has always been one of the universal strategies for improving photocatalytic performance. Herein, Ce‐doped Bi 2 MoO 6 monolayers were prepared for the photocatalytic C–N coupling reaction. Effects of subsurface Ce dopants on photocatalysis were investigated deeply via a series of characterizations and density functional theory calculations. Especially, subsurface Ce facilitates the migration of photogenerated electrons and enhances the adsorption of nitrobenzene. Ce‐induced oxygen vacancies promote the formation of more frustrated Lewis acid–base pairs (Mo/O), facilitating the adsorption of benzyl alcohol. It establishes efficient pathways for the transfer of carriers to the reactants. Thus, the typical Ce (0.04 mmol)‐doped Bi 2 MoO 6 exhibited a nitrobenzene conversion of 94.5% and a secondary amine selectivity of 99.1%. This work focuses on the role of subsurface dopants in photocatalysis, providing new insights for the design of high‐efficiency photocatalysts and the investigation of structure–function relationships.