Preparation of High Performance Graphene by Acidification-assisted Hummers Method

Graphite oxide was firstly prepared by using Hummers method with natural flake graphite,with which graphene oxide was synthesized by supersonic oscillation.In the presence of reductant hydrazine hydrate,graphene oxide was then reduced to graphene by heating reflux.The structure of graphite,graphite oxide and graphene were all characterized by X-ray diffractometry and Raman spectra,the morphology of graphene was observed with a transmission electron microscope,and the electrochemical properties of graphene were investigated by cyclic voltammetry in a three electrode system.It can be known from the results that graphene with a thin folded structure and broadened diffraction peaks with weaker intensity,has the integrity between graphite and graphite oxide and a disorder graphite structure with the stacking orientation.The double-layer current of graphene is far larger than that of conductive carbon black XC-72,indicating a higher electrochemical active surface for graphene.