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.