In situ synthesis of a reduced graphene oxide/cuprous oxide nanocomposite: a reusable catalyst

Abstract

A reduced graphene oxide/cuprous oxide (RGO/Cu₂O) nanocomposite has been successfully synthesized applying a simple in situ reduction method using an aqueous solution of lactulose which is used simultaneously as a reducing and stabilizing agent. Lactulose, a disaccharide, has the ability to reduce both GO and CuSO₄ in situ under alkaline conditions. The GO and RGO/Cu₂O nanocomposites are characterized using transmission electron microscopy, energy dispersive X-ray spectroscopy, field emission scanning electron spectroscopy, X-ray diffraction, Fourier-transform infrared spectroscopy and UV-vis absorption spectroscopy. The surface charge as well as stability is established by analyzing the zeta potential value. The results confirm the synthesis of the RGO/Cu₂O nanocomposite and the existence of interactions between Cu₂O and RGO. It is also observed that Cu₂O nanoparticles with an average size of 5 nm are uniformly dispersed throughout the RGO sheets. The catalytic activity of the RGO/Cu₂O nanocomposite is excellent for the ‘click’ reaction and remains the same for six cycles.