Vertically Aligned WS₂ Nanosheets for Water Splitting

Vertically aligned WS 2 (VAWS 2 ) nanosheet films are prepared using a lithium based anodization electrolyte to fabricate WO 3 films followed by sulfurization. The VAWS 2 synthesized here is self‐organized as a conformal structure to expose active edge sites for water splitting. These vertically aligned nanosheets are composed of exfoliated WS 2 to provide abundant active edges for catalytic reactions. Hydrogen evolution activity of the VAWS 2 is demonstrated to show high catalytic current, low onset overpotential and small Tafel slope. By certain measures, this VAWS 2 nanosheet film outperforms some of the state‐of‐the‐art hydrogen evolution reaction (HER) catalysts, which opens up a new pathway to simply and scalably fabricate high‐performance water electrolysis catalysts.