Realization of Wafer‐Scale 1T‐MoS 2 Film for Efficient Hydrogen Evolution Reaction

The octahedral structure of 2D molybdenum disulfide (1T‐MoS 2 ) has attracted attention as a high‐efficiency and low‐cost electrocatalyst for hydrogen production. However, the large‐scale synthesis of 1T‐MoS 2 films has not been realized because of higher formation energy compared to that of the trigonal prismatic phase (2H)‐MoS 2 . In this study, a uniform wafer‐scale synthesis of the metastable 1T‐MoS 2 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‐MoS 2 at 150 °C. Electrochemical analysis of 1T‐MoS 2 shows enhanced catalytic activity for the hydrogen evolution reaction (HER) compared to that of previously reported MoS 2 electrocatalysts 1T‐MoS 2 does not transform into stable 2H‐MoS 2 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.