Tuning interlayer spacing of MoS2 for enhanced hydrogen evolution reaction.

• MoS 2 with expanded interlayered spacing realizes the enhanced H 2 production. • MoS 2 -1.12 achieves a prominent energy band structure for H 2 production. • Both optical and electric property are dramatically enhanced. • The MoS 2 -1.12@Au core-shell structure is designed to boost H 2 production. The MoS 2 with different interlayer space were obtained with a hydrothermal method. The photocatalytic performance can be improved because of the enhanced light absorption ability, proper energy structure and boosted carrier separation and transportation ability. ga1 The MoS 2 structure engineering including hybrid structure construction and material self-optimization (edge sites improvement and phase transition), is a potential solution to boost photocatalytic hydrogen evolution reaction (HER) performance. Among the influence factors to MoS 2 structure, the interlayer distance, which is a significant and non-ignorable parameter, plays a momentous role in tuning the photoelectric property and photocatalytic activity of MoS 2. Here, we prepare MoS 2 with different interlayer distances, and explore the corresponding optical and electrical properties. As the MoS 2 interlayer spacing expands, the MoS 2 -1.12 (interlayer spacing 1.12 nm) is equipped with optimal light absorption ability, broadened energy band structure, high carrier mobility, and good electron transfer performance, compared to the MoS 2 -0.87 (interlayer spacing 0.87 nm) and MoS 2 -0.62 (interlayer spacing 0.62 nm). Consequently, the sample MoS 2 -1.12 possesses better HER performance (hydrogen production rate 311.28 μmol/g/h) than the MoS 2 -0.87 and MoS 2 -0.62. In addition, the MoS 2 @Au core-shell structure with optimal interlayer distance is designed to further enhance the HER ability, and the H 2 production rate of the MoS 2 -1.12@Au (773.4 μmol/g/h) is 2.48 times than that of the MoS 2 -1.12. The remarkable enhancement originates from the additional plasmonic Au nanoparticles. These results are significant for developing promising MoS 2 -based photocatalysts in the field of photocatalytic HER. [ABSTRACT FROM AUTHOR]