In situ inducing CoFe LDH to nanosheet arrays as efficient superaerophobic electrocatalysts for anion exchange membrane water electrolysis

Design of efficient non-precious metal electrodes for anion exchange membrane water electrolysis (AEMWE) is an ongoing challenge. We in-situ constructed a CoFe LDH nanosheet array (CoFe LDH NS array) on Nickel foam. Only 275 mV of low overpotential was required for the electrode to achieve a current density of 1000 mA cm^-2 for OER and stable operation for over 200 hours. The high catalytic activity, mechanical stability as well as electrical conductivity could be ascribed to the intimate interfacial contact between NF substrate with NiS intermediate layer and CoFe LDH. Moreover, the unique superaerophobic surface of the nanosheet arrays promoted the release of the bubble and the re-engagement of the electrolyte with the active sites. In-situ Raman results certified that in the OER process, CoOOH was the true active phase of the catalyst. In AEMWE tests, CoFe LDH-NS arrays || Pt/C/CP arrays outperformed commercial IrO₂ at 80 °C and 1.62 V to actuate 1 A cm^-2, and stable operating over 1500 hours. This morphology-dependent enhancement strategy may lead to new references for efficient electrode design for the next generation of AEMWE.