One‐dimensional phenanthroline‐based covalent organic framework bearing single cobalt atoms for efficient photocatalytic CO₂ reduction

Metalated covalent organic frameworks (COFs) for 2D and 3D topologies are continuously being developed, whereas metalated COFs with 1D topologies are still in their infancy. Here, a novel 1D phenanthroline‐based COF containing 4,4‐(1,10‐phenanthroline‐2,9‐diyl)bis[benzaldehyde] (PBA) is reported (PAD‐COF). Subsequently, a metalated 1D COF, Co SAS/PAD‐COF, is constructed using the bidentate ligand properties of PBA and anchoring the single Co atoms in PAD‐COF through a post‐synthetic modification strategy. This complex significantly improved the photocatalytic performance of PAD‐COF, and the CO yield of the optimized Co SAS/PAD‐COF was stable at 3091 µmol g −1 h −1 with a selectivity of 93%, which is approximately 43.7 times that of the original PAD‐COF. Experimental and theoretical results demonstrate the excellent CO 2 photoreduction activity of Co SAS/PAD‐COF owing to the synergistic effect of single Co catalytic sites and PAD‐COF. Among them, PAD‐COF, as the host, adsorbs CO 2 molecules and loads single Co atoms. Meanwhile, Co atoms function as catalytic sites and promote the adsorption and activation of CO 2 , while reducing the reaction energy barrier formed by the *COOH intermediates. Therefore, this unique metalated 1D COF provides a fresh approach to photocatalytic CO 2 reduction.