Three-Dimensional\nCo₃O₄@NiMoO₄ Core/Shell Nanowire\nArrays on Ni Foam for Electrochemical Energy Storage

Abstract

In this work, we report a facile\ntwo-step hydrothermal method to synthesize the unique three-dimensional\nCo₃O₄@NiMoO₄ core/shell nanowire\narrays (NWAs) on Ni foam for the first time. The Co₃O₄ nanowires are fully covered by ultrathin mesoporous NiMoO₄ nanosheets. When evaluated as a binder-free electrode for\nsupercapacitors in a 2 M KOH aqueous solution, the Co₃O₄@NiMoO₄ hybrid electrode exhibits a greatly enhanced\nareal capacitance of 5.69 F cm^–2 at a high current\ndensity of 30 mA cm^–2, nearly 5 times that of the\npristine Co₃O₄ electrode (1.10 F cm^–2). The energy density of the hybrid electrode is 56.9 W h kg^–1 at a high power density of 5000 W kg^–1. In addition, the Co₃O₄@NiMoO₄ hybrid\nelectrode also exhibits good rate capability and cycling stability,\nwhich would hold great promise for electrochemical energy storage.