Controlled synthesis of Ni3C/nitrogen-doped carbon nanoflakes for efficient oxygen evolution

Abstract Ni3C is very promising in electrocatalytic field. However, it is rarely reported due to its harsh synthesis conditions. Herein, pure metallic Ni3C nanoparticles in situ embedded in two-dimensional (2D) nitrogen-doped carbon nanoflakes (Ni3C/NC nanoflakes) are successfully prepared through one-step pyrolyzing Ni-urea complex at a relatively mild temperature at 350 °C. The composition and nanostructure of the catalyst can be easily controlled by adjusting the synthetic conditions, such as pyrolysis temperature and reactant concentration. The NC nanoflakes with a large specific surface area and massive mesopores present a 2D morphology, which is beneficial to disperse Ni3C nanoparticles to maintain their high conductivity. Based on advantage of nanostructure, Ni3C/NC nanoflakes exhibit high electrocatalytic performance with a low overpotential of 309 mV, small Tafel slope of 72 mV dec−1, as well as good stability. Furthermore, this study could provide a new strategy for the design and fabrication of other transition-metal carbides.