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 mu molg(-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 mu molg(-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)/onedimensional (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.