CO 2 ‐Induced 2D Ni‐BDC Metal–Organic Frameworks with Enhanced Photocatalytic CO 2 Reduction Activity

Abstract The rational design of 2D metal–organic framework (MOF) nanosheets with high active exposed surfaces and ultrathin thickness is a critical issue for CO 2 reduction. How to fabricate 2D MOFs and simultaneously fulfill the strong adsorption and activation of CO 2 molecules is a great challenge. Here, it is reported that CO 2 molecules can help to fabricate single‐layer [Ni 3 (OH) 2 (1,4‐BDC) 2 ‐(H 2 O) 4 ]·2H 2 O, BDC = 1,4‐benzenedicarboxylate, (Ni‐BDC) MOF nanosheets with large sizes and uniform thickness by exchanging with the coordinated H 2 O molecules at Ni sites and further orientated chemically adsorption on it. CO 2 molecules can not only help break the interlayer hydrogen bond of bulk materials realizing the successful transformation from 3D to 2D, but also contribute to expose the (200) planes with highly active in photocatalytic CO 2 ‐to‐CO conversion, and a high production rate of 104 mmol g −1 h −1 and a high Faraday efficiency of 96.8% can be obtained. This strategy provides a novel prototypical model based on the strong interaction between metal active centers and reactive molecules to obtain 2D MOFs with high quality and activity.