Facile Synthesis of Graphene-Wrapped Honeycomb MnO₂ Nanospheres and Their Application in Supercapacitors

Abstract

Graphene-wrapped MnO(2) nanocomposites were first fabricated by coassembly between honeycomb MnO(2) nanospheres and graphene sheets via electrostatic interaction. The materials were characterized by means of X-ray diffraction, scanning electron microscopy, transmission electron microscopy, atomic force microscopy, and thermogravimetric analysis. The novel MnO(2)/graphene hybrid materials were used for investigation of electrochemical capacitive behaviors. The hybrid materials displayed enhanced capacitive performance (210 F/g at 0.5 A/g). Additionally, over 82.4% of the initial capacitance was retained after repeating the cyclic voltammetry test for 1000 cycles. The improved electrochemical performance might be attributed to the combination of the pesudocapacitance of MnO(2) nanospheres with the honeycomb-like "opened" structure and good electrical conductivity of graphene sheets.

Flexible all-solid-state micro-supercapacitor based on Ni fiber electrode coated with MnO2 and reduced graphene oxide via electrochemical deposition

“…The areal specific capacitance (C A ) could be calculated from the cyclic voltammograms (CV) curves according to Equation (1) [37]:…”

Graphene-wrapped hierarchical TiO2 nanoflower composites with enhanced photocatalytic performance

“…The compounds used for this purpose, such as poly(allylamine hydrochloride), 142 (3-aminopropyl)trimethoxysilane, 147 and aminopropyltrimethoxysilane 148 are often toxic and unnecessarily detrimental to the environment. Little work has been done on graphene-wrapped TiO2, and to the best of my knowledge graphene-wrapped TiO2 hierarchical structures have not been studied.…”

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Fabrication of Ce-doped MnO2decorated graphene sheets for fire safety applications of epoxy composites: flame retardancy, smoke suppression and mechanism

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