Chrysanthemum-like spinel nanomaterials assembled with bundled nanowires as an efficient catalyst for the oxygen evolution reaction

Abstract

The fabrication of low-cost and high-performance electrocatalysts is essential for water splitting to achieve a sustainable oxygen evolution reaction. In this work, spinel oxides (CuCo₂O₄ and Co₃O₄) are mounted on nickel foam (NF) to form chrysanthemum-like hybrid crystal structures assembled from nanowires. The as-synthesized CuCo₂O₄–Co₃O₄/NF shows a high surface area, a large number of mesoporous structures and excellent charge transfer channels, which is conducive to the generation and overflow of O₂. And the synergistic effect, as well as the transfer of electron density between CuCo₂O₄ and Co₃O₄, contributes to the enhancement of OER activity. As a result, CuCo₂O₄–Co₃O₄/NF exhibits excellent OER performance with an overpotential of only 267 mV at 10 mA cm⁻², a low Tafel slope (114.6 mV dec⁻¹) and excellent stability with a scarce loss of the initial catalyst activity over 24 h under alkaline conditions. This work provides an effective method to show higher catalytic activity by combining two spinel oxides.