1D Covalent Organic Frameworks with Tunable Dual‐Cobalt Synergistic Sites for Efficient CO 2 Photoreduction

Abstract Diatomic catalysts enhance photocatalytic CO 2 reduction through synergistic effects. However, precisely regulating the distance between two catalytic centers to achieve synergistic catalysis poses significant challenges. In this study, a series of one‐dimensional (1D) covalent organic frameworks (COFs) are designed with adjustable micropores to facilitate efficient CO 2 photoreduction. CO 2 molecules are anchored between dual‐cobalt centers within micropores, thus effectively reducing their activation energy and initiating the photocatalytic process. Additionally, the formation of *COOH intermediates is significantly influenced by the coordination microenvironment around dual‐cobalt sites. Notably, COF‐Co‐N 4 exhibited remarkable CO 2 photoreduction activity with a CO evolution rate of 110.3 µmol·g −1 ·h −1 , which surpasses most of previously reported single‐atom‐site photocatalysts. Comprehensive characterization and density functional theory (DFT) calculations revealed that 1D COFs with dual‐cobalt sites possess the ability to anchor CO 2 molecules, thereby enhancing the efficacy of synergistic catalysis. Simultaneously, COF‐Co‐N 4 with quadruple nitrogen coordination significantly reduced the energy barrier of crucial *COOH intermediate, facilitating efficient photocatalytic CO 2 reduction. This study meticulously modulated the coordination microenvironment surrounding dual‐cobalt synergistic sites, providing new insight into the design of high‐performance photocatalysts.