Ni-Fe-Co based mixed metal/metal-oxides nanoparticles encapsulated in ultrathin carbon nanosheets: A bifunctional electrocatalyst for overall water splitting

Abstract

Consistent design, noble metal-free, incredibly effective catalysts for overall water splitting is a significant challenge to satisfy the need for sustainable energy conversion applications. To enhance the structural behavior, ultrathin carbon nanosheets, apart from the present effort, deals with the supportive features of ion and mass transportation. Herein, we report a cost-effective single-step approach for in-situ fabrication of Ni-Fe-Co-based mixed metal/metal-oxides nanoparticles encapsulated in ultrathin carbon nanosheets (NFC@CNSs) via a simple pyrolysis process. At optimum conditions, it reveals notable activity with a low overpotential of 213 and 256 mV at 10 mA cm−2 of current density and a small tafel slope of 115.1 and 61.29 mV dec−1, for HER and OER in 1.0 M KOH, respectively. Further, the hierarchical flower-like morphology of the NFC@CNSs-700 catalyst exhibits plentiful microspores along with a wide specific SBET surface area of 145.39 m² g−1, which advantages to superior catalytic efficiency. A two-electrode system in an alkaline media can attain a current density of 10 mA cm−2 with a fairly low applied voltage of 1.590 V for overall water splitting. The result indicates that the strong coupling between tri-metallic mixed metal/metal oxides nanoparticles and carbon nanosheets is responsible for formulating such a remarkable electrochemical performance, electronic structure, and robust stability toward overall water splitting.