Synergistic metal halide perovskite@metal-organic framework hybrids for photocatalytic CO₂ reduction

The photocatalytic reduction of carbon dioxide (CO₂) into multi-electron carbon products remains challenging due to the inherent stability of CO₂ and slow multi-electron transfer kinetics. Here in, we synthesized a hybrid material, cesium copper halide (Cs₃Cu₂I₅) intercalated onto two-dimensional (2D) cobalt-based zeolite framework (ZIF-9-III) nanosheets (denoted as Cs₃Cu₂I₅@ZIF-1) through a simple mechanochemical grinding. The synergy in the hybrid effectively reduces CO₂ to carbon monoxide (CO) at 110 μmol/g/h and methane at 5 μmol/g/h with high selectivity, suppressing hydrogen evolution. Further, we have investigated additional Cs₃Cu₂I₅@ZIF hybrids with varying ZIF-9-III amounts, confirming their selective CO₂ reduction to methane over hydrogen. Density functional theory (DFT) calculations reveal a non-covalent interaction between Cs₃Cu₂I₅ and ZIF-9-III, with electron transfer suggesting potential for improved photocatalysis.