N, P (S) Co-doped Mo2C/C hybrid electrocatalysts for improved hydrogen generation

Recently, molybdenum carbide (Mo2C) has aroused tremendous interests as a potential candidate to replace Pt-based electrocatalysts for hydrogen evolution reaction (HER). However, the HER performance of Mo2C is intrinsically limited by the empty d-orbitals with a large density in Mo2C and the resulting strong Mo-H bonding. Heteroatom-doping is an effective route for tuning the d-orbitals of Mo2C and improving the catalytic activity. Hence, in this work, we design two facile pathways to synthesize unique N, P and N, S dual-doped Mo2C/C hybrid electrocatalysts as highly active HER catalysts. The co-doping of N, P and N, S involves the substitute of C atoms in both Mo2C crystals and carbon matrix for a better synergistic effect, and can further improve the HER activity of Mo2C electrocatalysts compared to individual N doping. As expected, the obtained N, P or N, S dual-doped Mo2C catalyst (NP-Mo2C or NS-Mo2C) exhibits lower electrochemical resistance, higher intrinsic activity of each active site, or larger electro-chemically active surface area (A(ECSP), for NP-Mo2C), thus leading to enhanced HER activity as well as stability in the acidic solution. (C) 2018 Elsevier Ltd. All rights reserved.