A novel template free synthetic strategy to graphene–iron oxide nanotube hybrid

Abstract

A magnetically separable graphene–iron oxide nanotube composite was synthesised for the first time via an adept template free hydrothermal route. The physical characterization of the material was done using XRD, FTIR, SEM, TEM and VSM analysis. A mechanism analogous to the Kirkendall effect, involving the diffusion of Fe²⁺ ions and consequent expansion of voids leading to the formation of hollow iron oxide nanotubes has been proposed in accordance with the results obtained from XRD and TEM analysis. The composite turned out to be an excellent adsorbent for the removal of toxic Cr(VI) ions. Adsorptive removal and magnetic separation was achieved quickly within 60 seconds which highlights the efficiency of the prepared hybrid. The isotherm analysis indicated that the adsorption data can be represented by the Langmuir isotherm model. The superior adsorptive removal efficiency of the composite can be attributed to the synergistic effect between graphene and the iron oxide nanotubes. Through this report, we have demonstrated the first attempt of a template free synthesis of iron oxide nanotubes and their incorporation on graphene sheets. Subsequently the composite's ability as an adsorbent was evaluated in its efficiency for Cr(VI) removal.