Nickel Metal-Organic Framework Monolayers for Photoreduction of Diluted CO₂ : Metal-Node-Dependent Activity and...

Photocatalytic conversion of diluted CO₂ into solar fuel is highly appealing yet still in its infancy. Herein, we demonstrate the metal-node-dependent performance for photoreduction of diluted CO₂ by constructing Ni metal-organic framework (MOF) monolayers (Ni MOLs). In diluted CO₂ (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 CO₂ but also is superior to most catalysts in pure CO₂ . Whereas isostructural Co MOLs is almost inactive in diluted CO₂ , indicating the performance is dependent on the metal nodes. Experimental and theoretical investigations show that strong CO₂ binding affinity of Ni MOLs is the crucial factor, which stabilizes the Ni-CO₂ adducts and facilitates CO₂ -to-CO conversion.