Shock-wave synthesis of multilayer graphene and nitrogen-doped graphene materials from carbonate

Abstract

A method for transforming carbonate into graphene using shock-wave loading is presented in this paper. Multilayer graphene was synthesized by impacting mixtures of calcium carbonate and magnesium using a detonation-driven flyer. Furthermore, by adding ammonium nitrate to the reaction system, nitrogen-doped graphene material was formed in a one-step shock-wave treatment. The recovered samples were characterized using various techniques such as transmission electron microscopy, Raman spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The shock synthesis of graphene materials requires a balance between the growth rate of graphene materials and the formation rate of carbon atoms. The pressure and temperature are two important factors affecting the synthesis of graphene materials. Shock-synthesized nitrogen-doped graphene material was demonstrated to act as a metal-free electrode with an efficient electrocatalytic activity and long-term operation stability for the oxygen reduction reaction via two- and four-electron pathways in alkaline fuel cells.