Birnessite MnO2-decorated hollow dandelion-like CuO architectures for supercapacitor electrodes

Abstract

Birnessite MnO2-decorated hollow dandelion-like CuO architectures are synthesized by a simple hydrothermal method in which tetraoctylammonium bromide is used as surfactant. X-ray diffraction spectroscopy and field emission scanning electron microscopy are applied to investigate the structure and morphology of the as-synthesized dandelion-like CuO hollow sphere and CuO/MnO2 core-shell nanostructures. Furthermore, the electrochemical properties of CuO/MnO2 core-shell structures electrodes are elucidated by cyclic voltammograms, galvanostatic charge/discharge tests and electrochemical impedance spectroscopy in 1 M Na2SO4 electrolyte. The result shows specific capacitance of 228 F g(-1) and a long-term cycling stability which retains 82.2 % of its initial capacitance even after 5000 cycles. Such a facile strategy to fabricate the hierarchical CuO/MnO2 core-shell structures with significantly improved functionalities opens up a novel avenue to design electrode materials on demand for high-performance supercapacitor applications.