Sub-nanometer Mono-Layered Metal-Organic Frameworks Nanosheets for Simulated Flue Gas Photoreduction.

The dilemma between the thickness and accessible active site triggers the design of porous crystalline materials with mono-layered structure for advanced photo-catalysis applications. Here, we report a kind of sub-nanometer mono-layered nanosheets (Co-MOF MNSs) through the exfoliation of a specifically designed Co 3 cluster-based metal-organic frameworks (MOFs). The sub-nanometer thickness and inherent light-sensitivity endow Co-MOF MNSs with fully exposed Janus Co 3 sites that can selectively photo-reduce CO 2 into formic acid under simulated flue gas. Notably, the production efficiency of formic acid by Co-MOF MNSs (0.85 mmol g -1 h -1 ) is ∼13 times higher than that of bulk counterpart (0.065 mmol g -1 h -1 ) under simulated flue gas atmosphere, which is highest in reported works up to date. Theoretical calculations prove that the exposed Janus Co 3 sites with simultaneously available sites possess higher activity when compared with single Co site, validating the importance of mono-layered nanosheet morphology. Our results might facilitate the development of functional nanosheet materials for CO 2 photo-reduction in potential flue gas treatment. This article is protected by copyright. All rights reserved.