Metallic Ni-Fe-Co Nanoparticles Doped with Ultrathin Carbon Nanosheets: A Highly Efficient Electrocatalyst for Overall Water Splitting

Consistent design and cost-effective multifunctional electrocatalyst that comprises of highly abundant earth elements are greatly need for sustainable energy conversion applications. The present study reports a facile single-step strategy for in-situ growth of NiFeCo nanoparticles doped-ultrathin carbon nanosheets (NFC@CNSs) with hierarchical like structure by pyrolysis method. NFC@CNSs catalyst at optimum condition exhibits an outstanding activity with a low overpotential 124 and 256 mV to achieve a current density of 10 mA cm-2 with a small tafel slope 119.22 and 67.83 mV dec-1 for hydrogen and oxygen evolution reactions, respectively, in 1.0 M KOH. Furthermore, NFC@CNSs exhibits the large electrochemical active surface area of 21.30 mF cm-2, highly specific SBET surface area 145.39 m² g-1, low charge transfer resistance 46.87 ohms which forms the superior catalytic performance. The two-electrode system constructed as anode and cathode in an alkaline electrolyzer can achieve a current density of 10 mA cm-2 by a fairly low applied cell-voltage of 1.566 V under the real water splitting condition. The result revealed that, the strong coupling between NiFeCo alloy nanoparticles and carbon nanosheets might have been responsible for formulating such a remarkable electrochemical performances, electronic structure, and robust stability toward overall water splitting. Additionally, ultrathin porous carbon nanosheets structure does not only provides substantial active sites, but also facilitates the charge transfer process during diffusion and saturation of electrolytes which ultimately boost-up catalytic performances. This work provides a facile single-pot approach to construct metal-doped nanostructured materials with earth-abundant elements for sustainable industrial applications.