Multiscale synergetic bandgap/structure engineering for the construction of full-spectrum-responsive heterostructured MoS2/SnS2 photocatalyst

A 2D-MoS2/2D-SnS2 photocatalyst with a van der Waals (vdW) heterojunction has been prepared in this work by the self-assembly of MoS2 nanosheets on the SnS2 microflake surface. The multi-scale micro-nano hierarchical structure of MoS2 with a narrow bandgap (1.27 eV) exhibits an obvious photothermal effect and significantly enhanced light absorption ability in the wide wavelength range of 200-2000 nm. Both experimental investigation and corresponding simulations based on the density functional theory demonstrate that the vdW interaction and internal electric field between MoS2 and SnS2 favor direct Z-scheme charge separation and transportation effectively. As a result, the optimized MoS2/SnS2 Z-scheme heterojunction photocatalyst with full-spectrum response displays excellent photocatalytic CO2 reduction performance. In particular, the MoS2/SnS2 photocatalyst was able to maintain excellent photocatalytic CO2 reduction performance under NIR light irradiation at 880 nm and achieved a maximum CO yield of 0.033 mmol cm(-2) h(-1) when the laser output power reached 20 W. This work may provide valuable guidance for the construction of vdW Z-scheme heterojunction photocatalysts for high-efficiency photocatalytic CO2 reduction and effective solar light utilization.