Enhancing oxygen evolution reaction efficiency via rapid bubble separation of highly dispersed FeCoNi alloy particles under magnetic field assistance

The rapid separation of bubbles is crucial for electrocatalyst to achieve efficient oxygen evolution reaction (OER). In this work, a highly dispersed FeCoNi alloy catalyst was fabricated via electrodeposition, and its OER performance was significantly enhanced through a magnetic field-assisted strategy. By comparing catalysts with different substrate structures, it was found that FeCoNi/Cu 2 S@CF-W catalyst based on nanowires exhibits optimal OER performance, and the current density could reach 100 mA cm −2 only with an overpotential of 270 mV. Its highly dispersed structure effectively promotes the electron transfer between the electrode and the electrolyte, and exposes more active sites, resulting in the largest electrochemical active surface area and the lowest Tafel slope, thus accelerating the reaction kinetics. The catalyst retains excellent stability after a 55 h chronoamperometric test. By improving the magnetic moment arrangement of the catalyst and the mass transfer of bubbles, the magnetic field-assisted method enhances the adsorption of reactants and oxygen-containing intermediates, increases the number of active sites participating in the reaction, and solves the difficult problem of smooth desorption of bubbles. With the assistance of magnetic field, the overpotential of FeCoNi/Cu 2 S@CF-W catalyst is further reduced by 39 mV, requiring only 231 mV at a current density of 100 mA cm −2 , while maintaining outstanding long-term stability. This work provides a rational design strategy for for developing efficient and stable non-noble metal electrocatalysts, and offers a promising approach to boost the OER performance of electrocatalysts.