Activation of nitrogen species mixed with Ar and HS plasma for directly N-doped TMD films synthesis.

Among the transition metal dichalcogenides (TMD), tungsten disulfide (WS) and molybdenum disulfide (MoS) are promising sulfides for replacing noble metals in the hydrogen evolution reaction (HER) owing to their abundance and good catalytic activity. However, the catalytic activity is derived from the edge sites of WS and MoS, while their basal planes are inert. We propose a novel process for N-doped TMD synthesis for advanced HER using N + Ar + HS plasma.

Synthesis of vertically aligned wafer-scale tantalum disulfide using high-Ar/HS ratio plasma.

Nanostructural modification of two-dimensional (2D) materials has attracted significant attention for enhancing hydrogen evolution reaction (HER) activity. In this study, the nanostructure of TaSfilms was controlled by controlling the Ar/HS gas ratio used in plasma-enhanced chemical vapor deposition (PECVD). At a high Ar/HS gas ratio, vertically aligned TaS(V-TaS) films were formed over a large-area (4 in) at a temperature of 250 °C, which, to the best of our knowledge, is the lowest temperature reported for PECVD.