A facile and cost-effective approach to the reduction of exfoliated graphite oxide using sodium hypophosphite under acidic conditions

Abstract

Herein we demonstrate that graphene production could be implemented through the chemical reduction of an exfoliated graphite oxide (GO) suspension using a sodium hypophosphite–hydrochloric acid mixture. The structure and composition of the resultant reduced GO (RGO) were confirmed by XRD, XPS and Raman spectra. The RGO exhibited high C/O atomic ratio (13.5), excellent thermal stability and high electrical conductivity (up to 380 S m⁻¹). We speculate that the strong reducibility of hypophosphorous acid derived from a sodium hypophosphite–hydrochloric acid solution is the main mechanism for oxygen reducing and graphite restructuring of GO sheets. Considering that all the raw materials used are of very low toxicity and widely available, this facile and green technique presented here will provide a promising method for the production of graphene on an industrial scale.