Direct Z-Scheme Heterojunction of Ligand-Free FAPbBr₃/α-Fe₂O₃ for Boosting Photocatalysis of CO₂ Reduction Coupled with Water Oxidation

This is the authors' abstract. We don't add key points for this paper.

Up to now, the majority of the developed photocatalytic CO₂ reduction systems need to use expensive sacrificial reductants as electron source. It is still a huge challenge to drive the photocatalytic CO₂ reduction using water as an electron source. Herein, we report a facile strategy for the construction of direct Z-scheme heterojunction of LF-FAPbBr₃/α-Fe₂O₃, which is manufactured by the in situ and two-step controlled growth of ligand-free formamidinium lead bromide (LF-FAPbBr₃) nanocrystals on the surface of α-Fe₂O₃ nanorods. The matchable energy levels and direct contact between LF-FAPbBr₃ and α-Fe₂O₃ significantly accelerate the interfacial charge transfer, with a charge separation efficiency (ηseparation) of 93%, much higher than that of 11% shown by the ligand-capped FAPbBr₃/α-Fe₂O₃ heterojunction. The resulting efficient separation and raised redox ability of photogenerated carriers endow the LF-FAPbBr₃/α-Fe₂O₃ heterojunction with an outstanding photocatalytic performance for CO₂ reduction (to CO and CH₄) coupled with water oxidation (to O₂), achieving a highest electron consumption rate of 175.0 μmol g⁻¹ h⁻¹ among the reported metal halide perovskite-based photocatalysts, which are 5 and 11 times higher in comparison with those of sole LF-FAPbBr₃ and ligand-capped FAPbBr₃/α-Fe₂O₃, respectively.