Growth of Multiorientated Polycrystalline MoS₂ Using Plasma-Enhanced Chemical Vapor Deposition for Efficient Hydrogen Evolution Reactions

Molybdenum disulfide (MoS₂) has attracted considerable attention as a promising electrocatalyst for the hydrogen evolution reaction (HER). However, the catalytic HER performance of MoS₂ is significantly limited by the few active sites and low electrical conductivity. In this study, the growth of multiorientated polycrystalline MoS₂ using plasma-enhanced chemical vapor deposition (PECVD) for the HER is achieved. The MoS₂ is synthesized by sulfurizing a sputtered pillar-shaped Mo film. The relatively low growth temperature during the PECVD process results in multiorientated MoS₂ with an expanded interlayer spacing of ~0.75 nm, which provides abundant active sites, a reduced Gibbs free energy of H adsorption, and enhanced intralayer conductivity. In HER applications, the PECVD-grown MoS₂ exhibits an overpotential value of 0.45 V, a Tafel slope of 76 mV dec^-1, and excellent stability in strong acidic media for 10 h. The high HER performance achieved in this study indicates that two-dimensional MoS₂ has potential as an electrocatalyst for next-generation energy technologies.