Hierarchical superhydrophilic/superaerophobic 3D porous trimetallic (Fe, Co, Ni) spinel/carbon/nickel foam for boosting oxygen evolution reaction

Commercial oxygen evolution reaction catalysts are required operation under high current density to achieve rapid gas generation during electrochemical water splitting; however, oxygen bubbles readily cover active surfaces of electrodes, impeding reaction kinetics. Here, we introduce a facile, low-cost, and easy large-scale preparation strategy to synthesize trimetallic (Fe, Co, Ni) spinel/carbon/nickel foam (FeCoNiOx/C/NF) electrodes with 3D network structures, and demonstrate that oxygen bubbles can be rapidly removed from the surface of electrodes with superhydrophilic/superaerophobic properties. The resulting FeCoNiOx/C/NF electrodes exhibit a low overpotential of 221 mV with extremely low Tafel slope of 21 mV dec−1 at a current density of 10 mA cm−2 in 1 M KOH. At a high current density of 500 mA cm−2, FeCoNiOx/C/NF electrodes show a low overpotential of 325 mV with long-term stability for 250 h.