Reduced graphene oxide composites with MWCNTs and single crystalline hematite nanorhombohedra for applications in water purification

Abstract

We report nanostructured composites based on single crystal hematite (Fe2O3), reduced graphene oxide (RGO) and functionalized multi-walled carbon nanotubes (MWCNTs), which were synthesized via the hydrothermal method. The Fe2O3/MWCNT/RGO composite exhibits enhanced photocatalytic activity in terms of the degradation of Rhodamine B under visible irradiation compared with Fe2O3, or the Fe2O3/MWCNT or Fe2O3/RGO composites. The Fe2O3 and composite samples were analyzed using X-ray diffraction, field-emission scanning electron microscopy, high-resolution transmission electron microscopy, Brunauer–Emmett–Teller theory, and ultraviolet–visible spectrophotometry. From these analyses, we find that a uniform distribution of MWCNTs and RGO sheets with Fe2O3 nanorhombohedra results in an increase in the specific surface area and optical absorbance, as well as a reduction in the charge carrier recombination rate, and favorable charge transport properties were observed using photoelectrochemical measurements. This synthesis method represents a technique for fabrication of composite materials with low cost, and that are suitable for photocatalysis, with potential applications in water purification.