Bifunctional core–shell co-catalyst for boosting photocatalytic CO 2 reduction to CH 4

Solar-light-driven CO 2 reduction CO to CH 4 and C 2 H 6 is a complex process involving multiple elementary reactions and energy barriers. Therefore, achieving high CH 4 activity and selectivity remains a significant challenge. Here, we integrate bifunctional Cu 2 O and Cu-MOF (MOF = metal-organic framework) core–shell co-catalysts (Cu 2 O@Cu-MOF) with semiconductor TiO 2 . Experiments and theoretical calculations demonstrate that Cu 2 O (Cu + facilitates charge separation) and Cu-MOF (Cu 2+ improves the CO 2 adsorption and activation) in the core–shell structure have a synergistic effect on photocatalytic CO 2 reduction, reducing the formation barrier of the key intermediate ⋆ COOH and ⋆ CHO. The photocatalyst exhibits high CH 4 yield (366.0 µmol·g −1 ·h −1 ), efficient electron transfer (3283 µmol·g −1 ·h −1 ) and hydrocarbon selectivity (95.5%), which represents the highest activity of Cu-MOF-based catalysts in photocatalytic CO 2 reduction reaction. This work provides a strategy for designing efficient photocatalysts from the perspective of precise regulation of components.