Immobilization of Nickel- and Cobalt-Based Complexes in NH2-UiO-66 for Efficient CO2 Photoreduction

The photocatalytic reduction of carbon dioxide (CO2) to carbon-based materials is challenging because of its intricate nature and the generation of multiple byproducts. Hence, developing photocatalysts with a high CO2-reduction yield and selectivity is critical. In this study, new photocatalysts (U-B-M, M = Co, Ni) were synthesized by incorporating 1,2-benzisothiazolin-3-one (BIT) into NH2-UiO-66, to create N, N'-chelating sites via an amine–aldehyde condensation reaction, followed by metal-ion chelation. The introduction of BIT decreased the resistance of the catalyst and enhanced the separation of photogenerated carriers. The catalytic performance of U-B-Ni (rate: 3.10 mmol·g−1·h−1; selectivity: 97 %) surpasses those most of all previously reported MOF-based photocatalysts. Moreover, U-B-Ni shows high stability and negligible deactivation on catalytic cycling for over 16 h. This study expands the utility of metal–organic frameworks (MOF) in photocatalysis and highlights the importance of amine–aldehyde condensation in MOF modification.