Enhanced hydrogen evolution via interlaced Ni₃S₂/MoS₂ heterojunction photocatalysts with efficient interfacial contact and broadband absorption

The development of transition-metal sulfides, such as nickel sulfides (e.g., Ni₃S₂), as catalysts for the hydrogen evolution reaction is one potential solution to environmental pollution and energy crisis. However, its limited utilization of visible light and high recombination ratio of photoinduced electron–hole pairs suppress its photocatalytic activity. The key issue in improving photocatalytic efficiency lies in fabricating a p–n heterojunction with efficient interfacial contact and broadband absorption. Here, we developed a method for fabricating an interlaced Ni₃S₂/MoS₂ heterostructure with close interfacial contact. In our fabrication approach, a porous Ni₃S₂ scaffold is prepared by chemical vapor deposition and a hydrothermal method is used to prepare a Ni₃S₂/MoS₂ photocatalyst with close interfacial contact. The numerous interfaces of the interlaced Ni₃S₂/MoS₂ heterostructures promote effective electron–hole pair separation and facilitate electron transfer. Meanwhile, the hybrid Ni₃S₂/MoS₂ nanostructures favor broadband absorption extending from 300 to 800 nm. As a result, the hybrid Ni₃S₂/MoS₂ exhibits a remarkable rate of hydrogen evolution (540.75 μmol g⁻¹ h⁻¹), which is 5.71 and 3.89 times greater than those of pure Ni₃S₂ and MoS₂, respectively, under otherwise identical conditions. The results of this work are significant for developing promising transition-metal sulfide heterostructures in the field of hydrogen evolution by photocatalytic water splitting.