2H and 2H/1T-Transition Metal Dichalcogenide Films Prepared via Powderless Gas Deposition for the Hydrogen Evolution Reaction

The cathodic process in electrochemical water electrolyzers, the hydrogen evolution reaction (HER), is an extremely important reaction as it produces clean H₂ gas that can be utilized in a fuel cell to create electricity as an energy source for the increasing energy consumption of today's World. Transition metal dichalcogenide (TMD) materials have emerged as a competitor to Pt catalysts for the HER; however, the HER catalytic activity of TMD materials depends on various parameters including their fabrication route. Herein, we present a one-step powderless deposition growth process of 2H-MoS₂ and 2H-WS₂ materials on their native metals which serve directly as electrodes. The 2H phase TMDs were subsequently partially converted to the 1T-phase by a tert-butyllithium immersion treatment. The 2H and 2H/1T phase TMD foils were utilized for electrochemical hydrogen evolution, and we show that these TMD foils outperform or rival other MoS₂ and WS₂ materials in the literature fabricated by powder-based deposition/growth techniques. These findings highlight the importance of developing new scalable fabrication routes for HER catalysts in the race toward clean energy production.