MnO2@colloid carbon spheres nanocomposites with tunable interior architecture for supercapacitors

MnO2@colloid carbon spheres nanocomposites with tunable interior architecture have been synthesized by a facile and cost-effective strategy at room temperature. The structure and morphology of as-prepared nanocomposites were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), nitrogen adsorption, focused ion beam scanning electron microscopy (FIB/SEM) and high-resolution transmission electron microscopy (HRTEM). The as-obtained composites exhibited a three-dimensional architecture with core–shell, yolk–shell and hollow interior structure. Furthermore, the electrochemical properties of composites were evaluated by cycle voltammetric (CV) and galvanostatic charge–discharge measurements. The yolk–shell structure exhibited the optimized pseudocapacitance performance, revealing a specific capacitance (273 F g−1) with a good rate and cycling stability, owing to its unique structure and the poor crystallinity of MnO2 nanofilms. Therefore, this facile synthetic strategy could be useful to design and synthesis of tunable nanostructures with enhanced supercapacitor behavior.