Hierarchical MnMoO4/CoMoO4 heterostructured nanowires with enhanced supercapacitor performance

Abstract

Recent attention has been focused on the synthesis and application of complex heterostructured nanomaterials, which can have superior electrochemical performance than single-structured materials. Here we synthesize the three-dimensional (3D) multicomponent oxide, MnMoO₄/CoMoO₄. Hierarchical heterostructures are successfully prepared on the backbone material MnMoO₄ by a simple refluxing method under mild conditions; and surface modification is achieved. We fabricate asymmetric supercapacitors based on hierarchical MnMoO₄/CoMoO₄ heterostructured nanowires, which show a specific capacitance of 187.1 F g⁻¹ at a current density of 1 A g⁻¹, and good reversibility with a cycling efficiency of 98% after 1,000 cycles. These results further demonstrate that constructing 3D hierarchical heterostructures can improve electrochemical properties. 'Oriented attachment' and 'self-assembly' crystal growth mechanisms are proposed to explain the formation of the heterostructures.