Embedding CsPbBr₃ Quantum Dots into an In₂O₃ Nanotube for Selective Photocatalytic CO₂ Reduction to Hydrocarbon Fuels

Halide perovskite quantum dots (QDs) are one of the most prospective candidates for photocatalytic CO₂ reduction, but their photocatalytic performances are far from satisfactory due to structural instability and severe charge recombination. In this study, we demonstrated a CsPbBr₃ QDs/In₂O₃ hierarchical nanotube (CPB/IO) for efficient CO₂ conversion, in which CsPbBr₃ QDs were well-dispersed on the In-MOF-derived In₂O₃ nanotube by a facile self-assembly process. The optimized CPB/IO catalyst displayed an enhanced photocatalytic CO₂ performance with a (CO + CH₄) generation rate of 16.37 μmol·g^-1·h^-1 upon simulated solar illumination without a photosensitizer and sacrificial agent, which is 3.59 times stronger than that of pristine CsPbBr₃ QDs (4.56 μmol·g^-1·h^-1). Besides, the modified CsPbBr₃ QD catalyst exhibited an obvious increase of CH₄ selectivity and excellent stability after four cycles. The unique zero-dimensional (0D)/one-dimensional (1D) heterostructure and matching band potentials between CsPbBr₃ and In₂O₃ supply an intimate interfacial contact, numerous active sites, and effective charge transfer for CO₂ photoreduction. This work can inspire the formation of novel halide-perovskite-involving photocatalysts for solar fuel formation.