Structurally Locked Cobalt–Metalated Covalent Organic Frameworks for Enhanced Photocatalytic CO 2 Reduction

The development of efficient metal-based covalent organic frameworks (COFs) as photocatalysts for photocatalytic CO2 reduction remains highly desirable. However, traditional metallization strategies are significantly limited by the inefficient charge separation efficiency of these materials. Herein, two types of structurally locked metal-COFs, namely, BTT-Co-COF and BTT-Ni-COF, have been afforded via anchoring the metallic catalytic sites into COFs. This approach enables the COFs to exhibit enhanced structural rigidity and an excellent charge separation efficiency. Moreover, the BTT-Co-COF demonstrates a remarkable CO production rate of 12.2 mmol gcat–1 h–1 with 93% selectivity from CO2, which surpasses BTT-Ni-COF (5.5 mmol gcat–1 h–1) and BTT-COF (1.1 mmol gcat–1 h–1) in terms of CO production rate. Besides, the mechanism of photocatalytic CO2 reduction was also investigated through density functional theory calculations. This work offers a strategy to access structurally locked metal-covalent organic frameworks for the highly efficient production of syngas.