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 Bi₂MoO₆ 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 Bi₂MoO₆ 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.