A flexible high-performance oxygen evolution electrode with three-dimensional NiCo2O4 core-shell nanowires

Three-dimensional NiCo2O4 core-shell nanowires made up of NiCo2O4 nanowire core and NiCo2O4 nanoflake shell have been fabricated by a simple two-step wet chemical method on flexible conductive carbon cloth substrate for oxygen evolution reaction (OER). The combination of high surface area, enhanced mass and charge transport as well as three-dimensional conducting pathway enables superior oxygen evolution reaction. Notably, the NiCo2O4 core-shell nanowire electrode exhibits large anodic current and low onset overpotential for OER with an overpotential of similar to 320 mV at a current density of 10 mA/cm(2). Furthermore, the NiCo2O4 core-shell nanowire electrode possesses excellent electrocatalytic stability with long hour electrolysis showing no visible degradation, which is highly desirable for a promising OER electrocatalyst. (C) 2014 Elsevier Ltd. All rights reserved.