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

CsPbBr3 nanocrystals are in-situ grown on the surface of MoN nanosheets to construct a 0D/2D Schottky heterojunction with tight interfacial contact, thereby accelerating carrier separation and promoting CO2 reduction activity. [Display omitted] •In-situ growth of CPB NCs on the MoN nanosheets with contact interface.•Interfacial connections with highly efficient separation and transfer of the photoinduced electron-hole pairs.•Coupling with MoN nanosheets, CPB@MoN exhibited a 4.5 times increase in CO production activity.•In-situ DRIFTS revealed the photocatalytic mechanism over the CPB@MoN composite. 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.