2D/2D Schottky heterojunction of in-situ growth FAPbBr₃/Ti₃C₂ composites for enhancing photocatalytic CO₂ reduction

Mimicking the natural photosynthesis process to convert carbon dioxide into value-added chemicals is vital to solving both the climate crisis worldwide and the depletion of fossil fuels. Herein, we explore the synthesis of 2D FAPbBr₃ nanoplate combined with 2D Ti₃C₂ nanosheet to form a 2D/2D FAPbBr₃/Ti₃C₂ Schottky heterojunction using facile hot-injection and in-situ growth approaches. The Schottky heterojunction of FAPbBr₃/Ti₃C₂ over large interfacial contact provides abundant channels for transferring photogenerated carriers from FAPbBr₃ nanoplate to Ti₃C₂ nanosheet. The experimental results showed a CO yield of 93.82 μmol·g⁻¹·h⁻¹ with ethyl acetate/deionization water as a sacrificial reagent for FAPbBr₃/Ti₃C₂ composite, which was 1.25-fold enhancement that on pristine FAPbBr₃ nanoplates. The large 2D heterointerface can efficiently accelerate the spatial separation and transfer of photogenerated carriers and result in the superior photocatalytic activity and favorable stability of FAPbBr₃/Ti₃C₂ photocatalysts, which are proved by in-situ X-ray photoelectron spectroscopy, photoluminescence, transient absorption spectra, and Mott-Schottky measurement. Thus, this work unveils that 2D/2D Schottky heterostructures would significantly improve the reaction activities of halide perovskite-based photocatalysts.