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

Abstract

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.