Construction of unique NiCo2O4 nanowire@CoMoO4 nanoplate core/shell arrays on Ni foam for high areal capacitance supercapacitors

In this work, we present a facile two-step hydrothermal method with a successive annealing treatment to integrate two ternary metal oxides (NiCo2O4 and CoMoO4) into unique core/shell nanowire arrays (NWAs) on Ni foam as advanced binder-free electrodes for the first time. In addition, a possible growth mechanism for the growth of CoMoO4 nanoplates (NPs) on NiCo2O4 nanowires (NWs) is put forward based on the time-dependent experiments. When investigated as binder-free electrodes for supercapacitors (SCs), such unique NiCo2O4@CoMoO4 core/shell hybrid electrodes exhibit ultrahigh areal capacitances, which are several times larger than the pristine NiCo2O4 electrode. The remarkable electrochemical performance is attributed to the rational combination of two electroactive materials and the reasonable array configuration.