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

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.