Anchoring metal ions in amine-functionalized boron imidazolate framework for photocatalytic reduction of CO2

The photocatalytic reduction of CO₂ to energy-rich chemicals is highly appealing for alleviation of energy crisis and environment pollution. The introduction of different active sites is a key factor to determine the reaction activity and selectivity. Here, we demonstrate the metal ion-dependent performance for photocatalytic CO₂ reduction by anchoring transition metal ions (Co²⁺ and Ni²⁺) in an amine-functionalized boron imidazolate framework (BIF-43). As a result, Ni@BIF-43 realized a high selectivity of 90.2% for the CO₂-to-CO, while Co@BIF-43 achieved more efficient conversion with a high CO production rate of 2036.0 µmol g^?1 h^?1. Significantly, precise control of isolated metal site on a well-defined structure through coordination-assisted strategies enables us to better understand the specific effects of different metal-ion species on photoreduction of CO₂ as well as the catalytic mechanism.