Realization of Wafer-Scale 1T-MoS₂ Film for Efficient Hydrogen Evolution Reaction

The octahedral structure of 2D molybdenum disulfide (1T-MoS₂) has attracted attention as a high-efficiency and low-cost electrocatalyst for hydrogen production. However, the large-scale synthesis of 1T-MoS₂ films has not been realized because of higher formation energy compared to that of the trigonal prismatic phase (2H)-MoS₂. In this study, a uniform wafer-scale synthesis of the metastable 1T-MoS₂ film is performed by sulfidation of the Mo metal layer using a plasma-enhanced chemical vapor deposition (PE-CVD) system. Thus, plasma-containing highly reactive ions and radicals of the sulfurization precursor enable the synthesis of 1T-MoS₂ at 150 °C. Electrochemical analysis of 1T-MoS₂ shows enhanced catalytic activity for the hydrogen evolution reaction (HER) compared to that of previously reported MoS₂ electrocatalysts 1T-MoS₂ does not transform into stable 2H-MoS₂ even after 1000 cycles of HER. The proposed low-temperature synthesis approach may offer a promising solution for the facile production of various metastable-phase 2D materials.