Nickel Metal–Organic Framework Monolayers for Photoreduction of Diluted CO 2 : Metal‐Node‐Dependent Activity and Selectivity

Photocatalytic conversion of diluted CO 2 into solar fuel is highly appealing yet still in its infancy. Herein, we demonstrate the metal‐node‐dependent performance for photoreduction of diluted CO 2 by constructing Ni metal–organic framework (MOF) monolayers (Ni MOLs). In diluted CO 2 (10 %), Ni MOLs exhibit a highest apparent quantum yield of 1.96 % with a CO selectivity of 96.8 %, which not only exceeds reported systems in diluted CO 2 but also is superior to most catalysts in pure CO 2 . Whereas isostructural Co MOLs is almost inactive in diluted CO 2 , indicating the performance is dependent on the metal nodes. Experimental and theoretical investigations show that strong CO 2 binding affinity of Ni MOLs is the crucial factor, which stabilizes the Ni‐CO 2 adducts and facilitates CO 2 ‐to‐CO conversion.