Heterostructural modulation of in situ growth of iron oxide/holey graphene framework nanocomposites as excellent electrodes for advanced lithium-ion batteries

Chemically integrated hybrid nanostructures of Fe2O3/holey graphene frameworks (Fe2O3/HGF) nanocomposites have been successfully synthesized via a glycerol activated process. Defected graphene oxides were first etched by a certain volume of hydrogen peroxide. Subsequently, multi-dimensionally nanosized Fe2O3 particles were generated and anchored on the defected graphene layers. Based on this method, the ability in synthesizing the exquisitely tune Fe2O3 nanoparticles with highly controllable nanostructures and desirable properties is demonstrated, ranging from zero-dimensional quantum dots (similar to 4.42 nm) to one-dimensional nanorods, and eventually to two-dimensional nanosheets. As anodes for lithium-ion batteries, these hybrid Fe2O3/holey graphene frameworks electrodes exhibit excellent cyclic stability at 1 A g(-1) after 500 cycles (73.59 mAh g(-1) for quantum dots Fe2O3/HGF electrodes, 695.4 mAh g(-1) for nanosheets Fe2O3/HGF electrodes and 805.6 mAh g(-1) for nanorods Fe2O3/HGF electrodes, respectively) and specific capacity retention at the current density of 4 A g(-1) (427.6 mAh g(-1) for quantum dots Fe2O3/HGF electrodes, 374.2 mAh g(-1) for nanosheets Fe2O3 /HGF electrodes and 473.5 mAh g(-1) for nanorods Fe2O3/HGF electrodes, respectively). This work reveals a facile way to modify the oxygenic defect sites of carbon-based materials, providing more attaching sites for metal oxides, and hopefully accelerating the commercialization of carbon-based nanocomposites as anodes for metal-ion batteries.