Bimetallic iron cobalt oxide self-supported on Ni-Foam: An efficient bifunctional electrocatalyst for oxygen and hydrogen evolution reaction

Abstract

Water electrolysis offers an efficient way to store energy derived from renewable sources in the form of hydrogen. However, the practical implication of this technology is hindered by the lack of efficient earth abundant catalyst capable of accelerating both half reaction of water electrolysis. In this regards, herein; we have prepared a highly active composite electrode by depositing hierarchical spinel iron cobalt oxide on the surface of nickel foam. The layered morphology of iron cobalt oxide is ideal for effective transfer of electrolyte and facile dissipation of gaseous product. Moreover, intimate contact between the catalyst and the current collector caused a significant reduction in charge transfer resistance. Consequently, composite electrode displayed enhanced catalytic activity for HER and OER, achieving the benchmark current density of 10mAcm−2 at a low overpotential of 205mV and 244mV respectively. In addition, a two-electrode alkaline water electrolyzer constructed by employing the composite electrode as anode and cathode yielded a current density of 10mAcm−2 at an applied potential of only 1.62V. The long-lasting stability of iron cobalt oxide-Ni foam electrode along with its exceptional catalytic activity makes it a promising alternative to substitute the precious metal catalyst used in commercial water electrolyzer.