Interfacial synthesis of mesoporous MnO2/polyaniline hollow spheres and their application in electrochemical capacitors

Mesoporous MnO2/polyaniline composite (MP-I) has been synthesized using an interfacial synthesis technique. The results of X-ray diffraction and Fourier transform infrared spectroscopy indicate the amorphous structure of MP-I. The morphology of MP-I observed by scanning electron microscopy and transmission electron microscopy is composed of hierarchical hollow submicron spheres. The N2 adsorption/desorption test reveals MP-I has higher surface area (124 m2 g−1) and more uniform pore-size distribution than the composite (MP-C) prepared by chemical co-precipitation. The electrochemical measurements show that as electrode materials the mesoporous MP-I composite electrode yields larger specific capacitance (262 F g−1) with better rate capability and higher capacitance retention (93% of its initial capacitance after 800 cycles). The unique microstructure of MP-I and the coexistence of conducting polyaniline with MnO2 are found to be responsible for the superior electrochemical properties.

► Mesoporous MnO2/polyaniline composite is prepared using interfacial synthesis. ► The composite shows a hierarchical structure of hollow submicron spheres. ► The composite has large specific surface area and uniform mesopores. ► A high specific capacitance of 262 F g−1 is obtained for the new composite.