Nanohybrids of hematite nanoparticles and reduced graphene oxide nanosheets: Anode materials for lithium ion batteries

Abstract

The nanohybrids of hematite (α–Fe2O3) nanoparticles and reduced graphene oxide (rGO) nanosheets were prepared by a facial two-step chemical method. The αFe2O3 nanoparticles prepared by a sol-gel technique were hybridized with the pristine rGO nanosheets by ultra-sonication-assisted method. The rGO and α–Fe2O3 nanoparticles were dispersed in toluene to prepare (rGO)x/α–Fe2O3 nanohybrids. The crystal structure, vibrational modes, surface morphology, and elemental composition of these (rGO)x/α–Fe2O3 nanohybrids were investigated. The 3D nanostructure of α–Fe2O3 nanoparticles were randomly anchored on cross-linking rGO nanosheets. These rGO nanosheets functioned as mechanical support and an efficient electron conducting pathway in the (rGO)x/α–Fe2O3 nanohybrids. X-ray diffraction (XRD) spectra confirmed the crystal structure and phase purity while scanning electron microscopy (SEM) images showed the dispersion of α–Fe2O3 nanoparticles over rGO nanosheets. The hybridization of rGOs nanosheets with α–Fe2O3 nanoparticles significantly enhanced the electrochemical storage performance as anode material for LIBs. The first discharge capacity for the (rGO)x/α–Fe2O3 nanohybrids of 1469 mAh/gwas much better than that of the bare α–Fe2O3 nanoparticles of 895 mAh/g. Cyclic stability was enhanced as the discharge capacity was retained after 100 cycles for the (rGO)x/α–Fe2O3 nanohybrids. Moreover, the improved rate capability that was also observed for the (rGO)x/α–Fe2O3 nanohybrids further authenticates the use of these nanohybrids as anode materials for LIBs.