High catalytic activity and stability of visible-light-driven CO2 reduction via CsPbBr3 QDs/Cu-BTC core–shell photocatalysts†

Metal halide perovskites show great potential in photocatalysis, while intrinsic instability seriously hinders their application in photocatalytic CO₂ reduction. Coincidentally, metal–organic frameworks (MOFs) have garnered immense interest due to their unique characteristics of selective CO₂ absorption/activation, a large specific surface area, and highly active metal centers. Herein, in situ growth of a Cu-BTC coating on the surface of CsPbBr₃ quantum dots (CPB QDs) provides an effective photocatalyst for CO₂ reduction. The CPB QDs/Cu-BTC composites exhibit significant enhancements in moisture stability, CO₂ capture and activation capacity, and charge separation efficiency. Therefore, the CPB QDs/Cu-BTC heterojunction exhibits an enhanced CO production rate of 47.82 μmol g⁻¹ h⁻¹, which is 2.2- and 6.8-fold that of pristine CPB QDs and Cu-BTC, respectively. Moreover, a high CO selectivity of up to ∼100% is achieved. Based on in situ diffuse reflectance infrared Fourier transform (DRIFTS) spectra, CPB QDs/Cu-BTC composites facilitate the formation of HCO₃⁻ and ˙CO₂⁻ intermediates for converting CO₂ to CO through an adsorbed *COOH intermediate. This study sets up a new strategy to design excellent perovskite/MOF-based catalysts for promising catalysis.