Single-atomic rhenium-assisted 2H-to-1T phase transformation of MoS2 nanosheets boosting electrocatalytic hydrogen evolution

Abstract

Metallic (1T) molybdenum disulfide (MoS₂) with high electronic conductivity has been recognized as a promising catalytic material for the hydrogen evolution reaction (HER). However, there are still some challenges in obtaining high-degree and stable 1T-MoS₂ due to its thermodynamically metastable characteristics. Here, we reported the single-atomic rhenium (Re)-assisted 2H-to-1T phase transformation (ca. 85%) of MoS₂ nanosheets using a simple one-pot hydrothermal method. The resulting single-atomic Re doped 1T-2H MoS₂ heterostructures delivered small overpotentials of 34 and 38 mV at a current density of 10 mA cm⁻² in acid and alkaline media, respectively. Structural characterization and theoretical calculations indicate that the implantation of the Re single atom not only promotes the phase transition of MoS₂ from the 2H to 1T phase and charge redistribution through the constructed Re–S–Mo site but also the additional Re single atom acts as the active site to facilitate the dissociation of water and the adsorption of the hydrogen intermediate. All these factors effectively improve the electrocatalytic properties of MoS₂ for the HER.