Ni(II)-Dimeric Complex-Derived\nNitrogen-Doped Graphitized\nCarbon-Encapsulated Nickel Nanoparticles: Efficient Trifunctional\nElectrocatalyst for Oxygen Reduction Reaction, Oxygen Evolution Reaction,\nand Hydrogen Evolution Reaction

Abstract

The\nsuccessful commercialization of fuel cells and electrolyzer\nis limited to the cost and instability issues associated with electrocatalysts\n(platinum/platinum-based catalysts) used. Hence, there is critical\nchallenge to develop stable, non-platinum-based catalysts with multifunctionality\nand better durability that can efficiently replace platinum. While\na sufficient number of bifunctional catalysts are now known in the\nliterature, development of trifunctional catalyst is rarely reported.\nHerein, we report the development of nitrogen-doped graphitized carbon-encapsulated\nNi nanoparticles-based catalyst (Ni-NC700) from an easy derivable\nNi­(II)-dimeric complex. Microstructural studies reveal that the catalyst\nannealed at 700 °C has 4–5 layers of graphene sheets forming\na shell surrounding the Ni nanoparticles. This catalyst exhibits outstanding\ntrifunctional catalytic performance with onset potential of 0.86,\n1.52, and −0.02 V (vs RHE) for oxygen reduction reaction, oxygen\nevolution reaction, and hydrogen evolution reaction, respectively.\nThe long-term accelerated durability test and methanol tolerance test\nconfirm better stability and durability of this catalyst than those\nof the benchmark Pt/C. The development of N-doped graphitized carbon\nshell-encapsulated Ni nanoparticles from a small binuclear Ni­(II)\ncomplex will open a new horizon for the synthesis of efficient electrocatalysts\nwith trifunctionality.