Ultrasmall SnO2 nanoparticle-intercalated graphene@polyaniline composites as an active electrode material for supercapacitors in different electrolytes

Abstract

A ternary composite of graphene, SnO2 nanoparticles and polyaniline (PANI) was prepared by a two-step method using an ionic liquid and water as the solvents. First, reduced graphene oxide/SnO2 (RGO/SnO2) nanocomposites were synthesized within 10min using a microwave-assisted method in an ionic liquid without a reducing reagent. Second, the resulting RGO/SnO2 hybrids were coated with polyaniline (PANI) by the in situ polymerization of aniline in an aqueous medium. Transmission electron microscopy and scanning electron microscopy revealed ultrasmall SnO2 nanoparticles, ca. 5nm in size, intercalated with graphene layers and polyaniline (PANI). The composite modified electrodes exhibited a high rate capacity, such as 1012Fg−1 of Cs in 1M Na2SO4 at 4Ag−1. Furthermore, the proposed strategy provides a novel method for the fabrication of other ternary graphene-based composites with metal oxide and conducting polymers as electrode materials for supercapacitors.