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.