Boosting the Oxygen Evolution Reaction by Controllably Constructing FeNi₃/C Nanorods

Transition bimetallic alloy-based catalysts are regarded as attractive alternatives for the oxygen evolution reaction (OER), attributed to their competitive economics, high conductivity and intrinsic properties. Herein, we prepared FeNi₃/C nanorods with largely improved catalytic OER activity by combining hydrothermal reaction and thermal annealing treatment. The temperature effect on the crystal structure and chemical composition of the FeNi₃/C nanorods was revealed, and the enhanced catalytic performance of FeNi₃/C with an annealing temperature of 400 °C was confirmed by several electrochemical tests. The outstanding catalytic performance was assigned to the formation of bimetallic alloys/carbon composites. The FeNi₃/C nanorods showed an overpotential of 250 mV to afford a current density of 10 mA cm^-2 and a Tafel slope of 84.9 mV dec^-1, which were both smaller than the other control samples and commercial IrO₂ catalysts. The fast kinetics and high catalytic stability were also verified by electrochemical impendence spectroscopy and chronoamperometry for 15 h. This study is favorable for the design and construction of bimetallic alloy-based materials as efficient catalysts for the OER.