Ni and VN Nanoparticles Supported on N-Doped Carbon Layer Containing Ni Single Atoms as Electrocatalyst for the Hydrogen Evolution Reaction

The construction of highly active non-precious-metal electrocatalysts is the key to achieving an efficient hydrogen evolution reaction (HER). In this paper, a N-doped carbon layer composite was successfully synthesized by a self-limiting domain carbon thermal reduction strategy, in which the carbon layer was embedded with Ni/VN heterogeneous nanoparticles and Ni metal nanoclusters as well as anchored with many highly active Ni single atoms (denoted as Ni/VN/Ni-NC). The optimized Ni/VN/Ni-NC provides an abundance of active sites and high conductivity to facilitate efficient charge and mass transfer. And the electronic structure of Ni/VN heterostructures is optimized by the complementary effects of 3d orbital electrons, which contribute to the HER kinetics. The Ni/VN/Ni-NC exhibits excellent HER performance (without iR compensation) at a current density of 10 mA cm(-2) with overpotentials of 84 mV (1 M KOH solution) and 166 mV (1 M PBS solution).