LAUSR

Abstract Carbon modified MnO2 (CMMO) spheres have been fabricated through a facile low temperature (60 °C) hydrothermal method using mesoporous carbon spheres as reductive agent and sacrificial template and KMnO4 as manganese source. CMMO spheres with novel nanostructures such as flower-like and sea urchin-like are obtained by controlling the reaction time. The roles of mesoporous carbon in directing the growth of the CMMO spheres and controlling their morphologies have been investigated. The CMMO spheres are characterized by XRD, XPS, SEM, TEM, Raman spectra, TGA and N2 adsorption-desorption technique and electrochemical measurement. The resulted samples possess unique morphologies and regular pores, and their properties changed as reaction time proceed. The peseudocapacitive behaviors of the as-prepared samples are tested in two-electrode supercapacitors using 2 mol L−1 KOH aqueous solutions as electrolyte. A high gravimetric capacitance of 344 F g−1 at 1 A g−1 and the capacity retaining of 75% after 5000 cycles are achieved on the electrode prepared with one of the CMMO samples. The other CMMO samples also possess excellent electrochemical performance in comparison with the pristine mesoporous carbon (p-MC). Such superior electrochemical performance makes the porous CMMO spheres to be promising materials in the application of pseudocapacitors.