Plasma-treated 1D transition metal dichalcogenides for efficient electrocatalytic hydrogen evolution reaction

Significant research endeavors have been dedicated to the search for highly efficient and cost-effective hydrogen evolution reaction (HER) electrocatalysts. Due to their unique chemical structure and physical properties, bulk tungsten disulfide (WS₂) and its nanostructures are renowned electrocatalysts. This study reports a new modification method for the WS₂ nanotubes (NTs) surface through cold radiofrequency plasma. The effect of two plasmatic ions, i.e., D₂ and Ar, on WS₂ NTs has been investigated. When applied separately, both Ar and D₂ plasma-treated WS₂ nanotubes improved their electrocatalytic performances, yielding overpotentials of 348 and 343 mV at −10 mA cm⁻², respectively, compared to 567 mV of the untreated WS₂ nanotubes. Furthermore, combined plasma treatment by using Ar and D₂ plasma notably decreased the overpotential to 264 mV. The phenomenology behind inducing the surface conditions of the synergetic plasma treatment is discussed in the paper.