NixCu1−x/CuO/Ni(OH)2 as highly active and stable electrocatalysts for oxygen evolution reaction†
Abstract
Ni–Cu alloy-based nanomaterials are representative cost-effective materials that have been widely used as highly active and stable electrocatalysts for electrochemical energy applications, such as the water oxidation reaction, the methanol/ethanol reaction and many other small molecule oxidation reactions. Here, novel short needle-like complex oxides of NixCu1−x/CuO/Ni(OH)2 are rationally designed and synthesized to further promote their oxygen evolution reaction (OER) performance. Under the tuning of electron perturbation and surface morphology, Ni0.7Cu0.3/CuO/Ni(OH)2 reached an optimum performance of ∼136.6 mVRHE kinetic potential and ∼160 mVRHE (vs. 3.33 A g−1) over-potential with a Tafel slope of 66 mV dec−1. Furthermore, the complex oxides are directly grown on glass carbon, which works as a binder-free and carbon-free electrode, leading to an excellent stability of 200 000 s with 39% activity loss. Due to the electron perturbation role of Cu as well as the synergistic interactions among Ni–Cu, CuO and Ni(OH)2, the obtained Ni0.7Cu0.3/CuO/Ni(OH)2 complex oxide is significantly more active and stable than those of NixCu1−x alloy, CuO and Ni(OH)2. Our results demonstrate a general strategy to design cost-efficient OER electrocatalysts by using a conventional and easily accessible Ni0.7Cu0.3/CuO/Ni(OH)2 hybrids to possibly replace commercial Ru/Ir-based materials.