Au Multimer@MoS₂ hybrid structures for efficient photocatalytical hydrogen production via strongly plasmonic coupling effect

Photocatalytical water splitting of MoS₂ nanomaterials based on plasmonic nanoparticles (NPs) has been limited because of the insufficient utilization of plasmonic hot spots, which is an important strategy for efficient light harvesting. Here, we design a high-performance photocatalyst Au multimer@MoS₂ core-shell hybrid structures to address this issue. The Au NP's multimer with 5–10 nm inter-particle distance realized by a pre-decoration is employed as a plasmonic component. As expected, rationally structural arrangement provides a strong near-field coupling at their inter-particle gaps of Au NPs and then gives rise to strong absorption enhancement, which leads to the significant improvement of exciton generation and dissociation in the Au-MoS₂ junctions. Theoretical modeling and surface enhanced Raman scattering (SERS) have been used to demonstrate the enhanced optical effect; and the photoluminescence (PL) and electrochemical measurements are adopted to clarify the improved electrical effect. As a result, a 240.2% increment in hydrogen gas production amount (2997.2 μmol/g) is achieved as compared to that of the pure MoS₂ spheres (881.6 μmol/g). The hydrogen gas production amount of Au multimer@MoS₂ spheres is among the highest values reported in the plasmon-enhanced photocatalytic hydrogen production.