Pseudocapacitive Ni-Co-Fe Hydroxides/N-Doped Carbon Nanoplates-Based Electrocatalyst for Efficient Oxygen Evolution.

The oxygen evolution reaction (OER) catalytic activity of a transition metal oxides/hydroxides based electrocatalyst is related to its pseudocapacitance at potentials lower than the OER standard potential. Thus, a well-defined pseudocapacitance could be a great supplement to boost OER. Herein, a highly pseudocapacitive Ni-Fe-Co hydroxides/N-doped carbon nanoplates (NiCoFe-NC)-based electrocatalyst is synthesized using a facile one-pot solvothermal approach. The NiCoFe-NC has a great pseudocapacitive performance with 1849 F g specific capacitance and 31.5 Wh kg energy density. This material also exhibits an excellent OER catalytic activity comparable to the benchmark RuO catalysts (an initiating overpotential of 160 mV and delivering 10 mA cm current density at 250 mV, with a Tafel slope of 31 mV dec ). The catalytic performance of the optimized NiCoFe-NC catalyst could keep 24 h. X-ray photoelectron spectroscopy, electrochemically active surface area, and other physicochemical and electrochemical analyses reveal that its great OER catalytic activity is ascribed to the Ni-Co hydroxides with modular 2-Dimensional layered structure, the synergistic interactions among the Fe(III) species and Ni, Co metal centers, and the improved hydrophily endowed by the incorporation of N-doped carbon hydrogel. This work might provide a useful and general strategy to design and synthesize high-performance metal (hydr)oxides OER electrocatalysts.