Metallic phase WSe₂ nanoscrolls for the hydrogen evolution reaction

Nanostructured metastable metallic phase transition-metal dichalcogenides (TMDs) have attracted tremendous attention due to their promising practical applications in the hydrogen evolution reaction (HER). However, it is still quite challenging to construct metastable metallic phase TMD nanomaterials because of their thermodynamic metastable nature. In particular, metallic WSe₂ (M-WSe₂) nanoscrolls have seldom been reported before. In this work, we successfully synthesized M-WSe₂ nanoscrolls with a high percentage of metallic phase via a facile two-step method combined with Li-intercalation exfoliation and spontaneous curling procedures. We determined the metallic phase concentration of the M-WSe₂ nanoscrolls with X-Ray photoelectron spectroscopy. The as-prepared M-WSe₂ nanoscrolls were used as electrocatalysts for the HER, demonstrating much enhanced electrocatalytic performance compared to their 2H WSe₂ nanoscroll counterparts. This work may open up new opportunities to fabricate nanoscroll-structured metastable metallic TMDs for promising applications.