Ultrathin 2D/2D ZnIn2S4/MoS2 hybrids for boosted photocatalytic hydrogen evolution under visible light

A well-connected hetero-layered ZnIn₂S₄/MoS₂ composite was fabricated via an electrostatic self-assembly process to boost photocatalytic hydrogen evolution under visible-light irradiation. Ultrathin nanosheets contribute to efficient charge transfer by reducing electron diffusion length. In the sheet-on-sheet heterostructure, ultrathin ZnIn₂S₄ nanosheets (NSs) and MoS₂ NSs were well connected with each other to form a large and intimate contact interface, which features an efficient separation and migration of photoinduced charge carriers. Moreover, MoS₂ NSs endow the composite with abundant active sites and lowers its overpotential for water reduction. Consequently, the ultrathin hetero-layered ZnIn₂S₄/MoS₂ composite with optimized loading of MoS₂ achieves a hydrogen production rate of 4.974 mmol g⁻¹ h⁻¹, which is ca. 50 times as much as that of pure ZnIn₂S₄, and 2.2 times as much as that of its ZnIn₂S₄/Pt counterpart. This work provides inspiration for the fabrication of well-contacted hetero-layered structure for photocatalytic hydrogen evolution.