Photocatalysis represents a promising tool in organic synthesis, enabling chemical reactions to occur under mild conditions by utilizing light energy. As industries increasingly focus on sustainability, carbon nitride (C₃N₄)—a metal-free semiconductor—emerges as a key material due to its favorable properties, including an optimal band gap (~2.7 eV) and earth-abundant composition, making it an excellent candidate for visible-light-driven photocatalysis. Additionally, carbon nitride serves as an adaptable support for metal incorporation. Single-atom catalysts anchored on carbon nitride (M₁/C₃N₄) offer a significant advancement in catalytic performance, delivering high efficiency, stability, and tunability. This unique combination facilitates a dual photocatalytic system that harnesses both metal-catalyzed and semiconductor-driven mechanisms or precisely controls electron movement on the support.
In this work, we present single-atom (e.g., M = Pd, Ni, or Cu) anchored carbon nitrides to drive a variety of organic transformations, such as C−C, C−O, and C−N coupling reactions, S−S bond formation, alcohol oxidation, trifluoromethylation, and decarboxylation with excellent selectivity. Moreover, we demonstrate atomic site orthogonality in the M₁/C₃N₄ system, enabling cascade photo-redox reactions within a single framework. The system leverages visible light-generated electron-hole pairs from C₃N₄ to drive diverse redox reactions at its surface while facilitating various coupling reactions at the metal sites. This concept is broadly applicable to different catalytic reaction systems, establishing the site-orthogonal M₁/C₃N₄ photocatalyst as an ideal platform for enhancing the efficiency and selectivity of multistep organic transformations.

Hyeonjeong Son

Appearances