Morphology Effects on the Supercapacitive Electrochemical Performances of Iron Oxide/Reduced Graphene Oxide Nanocomposites

Abstract

The benzyl alcohol route is used to decorate reduced graphene oxide (RGO) nanosheets with iron oxide (FeOx) nano-particles. The resulting FeOx/RGO composites combine both electrical double-layer capacitive and pseudocapacitive behaviors of RGO and FeOx, respectively, owing to the hybrid nano-structure. In 1m Na2SO4 aqueous electrolyte, the capacitance of the FeOx/RGO electrode reaches 126 Fg(-1) in a negative potential range from -0.8 to 0.0 V (vs. Ag/AgCl) and 97 Fg(-1) in the extended potential window from -0.8 to + 0.7 V (vs. Ag/AgCl). By using the benzyl alcohol route, a higher concentration of iron precursor leads to full surface coverage of the RGO nanosheets by smaller FeOx nanoparticles, forming a close-packed layer that limits the restacking of RGO nonosheets in the dry state. The resulting FeOx/RGO composite gains the same power capability as RGO and a higher energy density than raw FeOx, owing to this well-designed morphology.