0D/2D Schottky heterojunction of CsPbBr3 nanocrystals on MoN nanosheets for enhancing charge transfer and CO2 photoreduction

Abstract

Solar-driven conversion of CO₂ to value-added chemical fuels has been regarded as a promising strategy for solving the climate problem and energy crisis. To realize this goal, it is vital to design photocatalysts with abundant catalytic active sites and excellent charge separation efficiency. Here, perovskite nanocrystals (CsPbBr₃) were anchored on two-dimensional molybdenum nitride (MoN) using an in-situ growth method, forming a new and effective 0D/2D CsPbBr₃@MoN (CPB@MoN) nanoheterosturcture with close contact interface for CO₂ photoreduction. The introduction of MoN, acting as a charge transfer channel, could quickly trap the photoinduced charge from CsPbBr₃ and provide abundant catalytic sites for CO₂ photocatalytic reactions. For optimized CsPbBr₃@MoN composites, the CO yield was 13.86μmol/gh⁻¹ without any sacrificial reagent, which was a 4.5-fold enhancement of the pure CsPbBr₃. Further, in-situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) revealed the catalytic mechanism for the CO₂ photoreduction process. This work provides a new platform for constructing superior perovskite/MoN-based photocatalysts for photocatalytic CO₂ reduction.