Coral-like FeCoNi alloy/layered double hydroxides/nickel foam for enhancing mass transfer in oxygen evolution reactions

Many oxygen evolution reaction electrocatalysts lose their ability to transfer mass at high current densities, leading to the adoption of renewable power to make “green” hydrogen a considerable problem. Here we construct gas evacuation configurations by integrating coral-like FeCoNi alloy/layered double hydroxides electrocatalysts on nickel foam (FCNal/NF) that can effectively avoid catalyst deactivation in high current density. During electrochemical water splitting, the superhydrophilic/superaerophobic surfaces reduce the adhesion of bubbles to electrodes. Moreover, the spontaneously generated slug flow within pores can facilitate contact between electrolytes and electrochemical active sites. Therefore, the optimized FCNal/NF electrode displays excellent catalytic activity (the overpotential of 166 mV at 10 mA cm⁻² in 1 M KOH) with long-term durability under both laboratory (1 M KOH, room temperature) and rigorous industrial (30 wt% KOH, 80 °C) conditions. In the anion exchange membrane water electrolysis (AEMWE) tests, FCNal/NF(+)||Pt/C/NF(−) electrolyzer requires 1.73 and 1.86 V to reach the current density of 1000 and 2000 mA cm⁻² for overall water electrolysis, respectively, showing its potential for industrial application.