Effect of anions on the preparation of graphene oxide by electrochemical exfoliation
Different anionic acids were employed as the electrolyte in the oxidation process to produce graphene oxide by electrochemical exfoliation method.The results indicated that graphene oxide could be successfully obtained in the presence of SO42-,NO3-and PO43-ions.When sulfuric acid was used as the electrolyte,SO42-promoted the generation of·OH radicals and reduced the surface tension of graphite intercalation compounds,resulting in the formation of graphene oxide with higher oxidation degree under identical process conditions.Furthermore,the oxidation degree of graphene oxide was positively correlated with its capacitance performance,cycle stability,and impedance.Specifically,the graphene oxide prepared with sulfuric acid as the electrolyte exhibited a specific capacitance of 30.5F/g at a current density of 0.5A/g and maintained 83％of its initial capacitance after 500 cycles.
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维普
