Post‐Cobaltization of Crystalline Trinuclear Copper Cluster‐Based Metal–Organic Frameworks for Photocatalytic CO 2 Reduction

Abstract The emergence of visible‐light photocatalytic frameworks provides a sustainable technology for dealing with CO 2 greenhouse gas. Herein, the solvothermal reaction of copper(I) cyclic trinuclear complex (Cu‐CTC) with 2,5‐dihydroxyterephthalaldehyde (2,5‐DHTA) or 3,3’‐dihydroxy‐ [1,1’‐biphenyl] ‐4,4’‐dicarbaldehyde (3,3’‐DHBDA) led to two crystalline hcb topological copper(I)‐organic frameworks USTB‐48 and USTB‐49, respectively. The post‐cobaltization of 2‐(benzylideneamino)phenol units in these two frameworks, providing the active catalytic centers in obtained USTB‐48(Co) and USTB‐49(Co) for photocatalysis of CO 2 reduction. The parent frameworks and post‐modificated species have been thoroughly characterized through powder X‐ray diffraction analysis and various spectroscopies. The combination of trinuclear copper units and single cobalt centers is able to achieve the CO generation rate up to ca . 8451 μmol⋅g −1 ⋅h −1 and 96 % selectivity for USTB‐48(Co).