Modulating microenvironment of active moiety in Prussian blue analogues via surface coordination to enhance CO2 photoreduction

Well-arranged photosensitive units and catalytic sites in closeness are critical for enhancing charge separation effectiveness and promoting photocatalysis. Here, a heterogeneous interface is constructed, which binds a deprotonated carboxyl group on perylene diimide (PDI) photosensitizer to unsaturated metal sites generated by etching of different Prussian blue analogues (PBAs). The atomically-dispersed metal sites and anchored photosensitive units greatly accelerate charge transfer. Typically, the S-scheme heterojunction built by etched NiCo PBA and PDI (NCSP) possesses bond of O-Ni. Density functional theory (DFT) and in-situ technology reveals the electron density of the Ni active site is optimized. Consequently, activation barrier of CO2 on the Ni site was reduced, thus improving the CO generation (60.0 μmol g−1) up to about 9 times than NiCo PBA. This work reveals key insights into the precise modulation of active moiety for efficient photocatalytic CO2 conversion.