Hierarchical Mo2C/C Scaffolds Organized by Nanosheets as Highly Efficient Electrocatalysts for Hydrogen Production

A facile and low-cost strategy is developed for the in situ synthesis of well-defined 3D porous scaffold-like Mo2C/C nanosheet hybrids as electrocatalysts for the hydrogen evolution reaction (HER). In this strategy, cubic NaCl particles play a critical template role in not only directing the formation of a 3D porous scaffold-like architecture but also creating a 2D-finite space to obtain Mo2C/C nanosheet hybrids. More importantly, the presence of NaCl will increase the content of amorphous carbon residue, reducing the charge transfer resistance. As a result, in this unique structure, the 3D porous scaffold can effectively avoid aggregation and expose more active sites, facilitating mass transportation, while the sheet-like Mo2C/C hybrids can achieve a relatively high density of catalytic sites with excellent charge transfer ability. Moreover, the effects of the mass ratio on the HER activity were also investigated. And the final optimized Mo2C/C electrocatalyst manifests an outstanding HER performance in both acidic and alkaline media with small Tafel slopes of 56 and 48 mV dec(-1), respectively.