Abstract
While photocatalytic CO(2) reduction has been intensively investigated, reports on the influence of anions coordinated to catalytic metal sites on CO(2) photoreduction remain limited. Herein, different coordinated anions (F(-), Cl(-), OAc(-), and NO(3) (-)) around single Co sites installed on bipyridine-based three-component covalent organic frameworks (COFs) were synthesized, affording TBD-COF-Co-X (X = F, Cl, OAc, and NO(3)), for photocatalytic CO(2) reduction. Notably, the presence of these coordinated anions on the Co sites significantly influences the photocatalytic performance, where TBD-COF-Co-F exhibits superior activity to its counterparts. Combined experimental and theoretical results indicate that the enhanced activity in TBD-COF-Co-F is attributed to its efficient charge transfer, high CO(2) adsorption capacity, and low energy barrier for CO(2) activation. This study provides a new strategy for boosting COF photocatalysis through coordinated anion regulation around catalytic metal sites.