Hetero-structured Ru–Mo2C nanoparticles loaded on N,P co-doped carbon for a pH universal hydrogen evolution reaction

Abstract

Considering the extensive research studies on Ru and Mo₂C for the hydrogen evolution reaction (HER), the construction of heterostructure catalysts containing both Ru and Mo₂C nanoparticles can further improve the catalytic activity by the synergistic effect of different species. In this work, we report the synthesis of N,P co-doped carbon coated Ru and Mo₂C nanoparticles for the HER using a ZnMo metal–organic framework (MOF) as the precursor. The addition of phosphomolybdic acid during the synthesis of a Zn-MOF not only provides a Mo source for the formation of Mo₂C, but also induces a nano-bowl structure. After anchoring RuCl₃ in the ZnMo-MOF and thermal annealing, Ru and Mo₂C nanoparticles encapsulated in N,P doped carbon (Ru–Mo₂C@NPC) were synthesized and the nano-bowl morphology was well preserved. Due to the co-existence of the highly active catalytic species Ru and Mo₂C, a large specific surface area owing to the evaporation of Zn during the calcination process, and the nano-bowl-like morphology that boosts mass transfer, Ru–Mo₂C@NPC exhibits good catalytic activity for the HER over a wide pH range, with overpotentials of 62, 64 and 170 mV in 0.5 M H₂SO₄, 1 M KOH and 1 M PBS solution at 10 mA cm⁻², surpassing the values for many Ru and Mo₂C based catalysts. This work provides a feasible route for designing high performance HER catalysts.