Ultra-thin wrinkled NiOOH–NiCr2O4 nanosheets on Ni foam: an advanced catalytic electrode for oxygen evolution reaction

Abstract

Here, we report the in situ electrochemical conversion of NiCr₂O₄ on Ni foam prepared using a hydrothermal strategy to give ultra-thin wrinkled NiOOH–NiCr₂O₄ amorphous–crystalline nanosheets on Ni foam (NiOOH–NiCr₂O₄/NF) via anode oxidation in 1.0 M KOH. Owing to the coordination of NiCr₂O₄ and NiOOH, NiOOH–NiCr₂O₄/NF shows superior catalytic activity toward the oxygen evolution reaction (OER) with the demand of overpotential as low as 271 mV to drive a geometrical current density of 20 mA cm⁻² under alkaline conditions. Notably, it also displays strong long-term electrochemical durability for at least 30 h.