"Synthesis of Graphene Oxide Sulfonated and Estimation of its Catalytic Activity in Conversion Reaction of Fructose to 5-Hydroxymethylfurfural "

Abstract

Graphene oxide (GO) was synthesized by Hummer method and sulfonated by (NH4)2SO4 solution. The obtained material was characterized by different methods such as XRD, IR, TEM, EDS. The XRD pattern showed the successful exfoliation of graphite with shift of diffraction maximum from 2q=26,5o to 10,4o. The TEM images released the existence of graphene oxide sheet in various sizes. The sulfo group formation (–SO3H) on graphene oxide surface was confirmed by IR spectra with the appearance of characteristic picks at 1401 cm-1 và 1124 cm-1 attributed to vibrations of groups S-O and S=O. Catalytic activity of GO-SO3H was estimated by reaction of fructose conversion into 5-hydroxymethylfufural (HMF). The different reaction parameters (temperature, time, solvent), were examined. It results that highest yield reaction attained 56% at 120oC, for 2h of reaction time and in solvent dimethyl sulfoxide (DMSO).