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. Plasma traetment induces chemical modiifcation in 1D WS2 nanotubes, enhancing its electrocatalytic performances upon HER.