Molten salt N-modified Mo2CTx as a non-precious metal catalyst for efficient hydrogen evolution reaction

Abstract

The two-dimensional molybdenum carbide (Mo2CTx) has a similar electronic structure to platinum, which has the potential to be one of non-precious metals catalysts for hydrogen evolution reaction (HER). However, the preparation of Mo2CTx by conventional HF and LiF–HCl etching method inevitably introduces the –F and –Cl terminations on the surface, which adversely affect activity and stability. In this study, the LiCl–KCl–Li3N molten salt was used to treat Mo2CTx at 600 °C and atmospheric pressure and introduce nitrogen heteroatoms. After treated in LiCl–KCl–Li3N molten salt, the HER performance of nitrogen-doped Mo2CTx is improved compared with that of un-doped Mo2CTx, which should be attributed to the optimization of the electronic structure of N–Mo2CTx and lower hydrogen adsorption energy barrier. This simple molten salt method provides a way to modify non-precious metal HER catalyst and introduce nitrogen heteroatoms.