Precisely modulate interfacial Bi-O bridge bond in Co-TCPP/Bi3O4Br to trigger long-lasting charge separation for boosting CO2 photoreduction

Insufficient charge separation and feeble CO2 activation limit the CO2 photoreduction efficiency. It is highly desirable to consciously construct organic-inorganic hybrid composites to simultaneously accelerate charge separation and provide favorable active sites. Herein, a defect-induced interfacial Bi-O bridge bond is constructed by grafting terminal O of cobalt porphyrin (Co-TCPP) with Bi3O4Br. Systematic investigations reveal that the BiO bridge bond as the charge migration bridge accelerates the extraction and transfer of electron from the external [Bi3O4] layers to Co-TCPP, and the millisecond separation lifetime of electrons on Co-TCPP can be achieved. Co atoms as the active sites optimized the CO2 adsorption and activation, thus promoting the formation of COOH*. As a result, the CO2 photoreduction rate of 0.5% Co-TCPP/Bi3O4Br reaches 71.3 mu mol g-1h-1 in pure water, 2.53fold of that on the pristine Bi3O4Br. This work provides atomistic insights and strategies for the construction of new organic-inorganic hybrid materials for artificial photosynthesis and CO2 photoreduction.