Hierarchical porous Ni, Fe-codoped Co-hydroxide arrays derived from metal–organic-frameworks for enhanced oxygen evolution

Abstract

The multi metal organic frameworks (BTC-CoNiFeZn) were used as the precursors of in situ structure reconstruction in alkaline solution, and we synthesized hierarchical porous Ni,Fe-codoped Co-hydroxide nanowire array (Ni_0.8Fe_0.2/Co-H NAs/NF) catalyst for the oxygen evolution reaction (OER). Benefiting from the rational micro-structure, rich ion-accessible nanopores, and abundant defect sites, the target catalysts possess enhanced intrinsic activity. The obtained Ni_0.8Fe_0.2/Co-H NAs/NF catalysts show superior OER catalytic activity with a low overpotential of 231 mV at 10 mA cm⁻², a small Tafel slope of 32.9 mV dec⁻¹, and high cycle stability for 135 h with performance degradation of only about 4.4%.