Dual-metallic single Ru and Ni atoms decoration of MoS2 for high-efficiency hydrogen production

Abstract The limitation of single-atom catalysts hinders its promotion and application in the HER field. Herein, we fabricated a dimetallic single-atom catalyst where monoatomic Ru and Ni co-modify MoS2 using a mild method (Ru/Ni-MoS2). Experiments combined with theoretical calculations indicated that the single Ru atoms were anchored through single Ni atoms with strong electronegativity, and most of the Ru atoms coordinated with the S were distributed on the Ni atop sites. And the synergistic effect of the Ru/Ni-MoS2 with S atoms bonded with Ni as hydrogen acceptor and single-atoms Ru as hydroxyl acceptor, effectively reduced the intermediate energy barrier of the water dissociation step. The as-fabricated Ru/Ni-MoS2 exhibited a super-low overpotential of 32 mV at 10 mA cm−2 with the corresponding Tafel slope of 41 mV·dec-1 as well as negligible current attenuation over 20 h, far surpassing that of Ru-MoS2 and Ni-MoS2. This work not only provides a high-efficiency HER catalysts, but also a new idea based on electronegativity difference and bimetallic single-atom regulation to design catalyst.