title: Large scale production of highly-qualified graphene by ultrasonic exfoliation of expanded graphite under the promotion of (NH4)2CO3 decomposition.
abstract: Highly-qualified graphene was prepared by the ultrasonic exfoliation of commercial expanded graphite (EG) under the promotion of (NH4)2CO3 decomposition. The yield of graphene from the first exfoliation is 7 wt%, and it can be increased to more than 65 wt% by repeated exfoliations. Atomic force microscopy, x-ray photoelectron spectroscopy and Raman analysis show that the as-prepared graphene only has a few defects or oxides, and more than 95% of the graphene flakes have a thickness of ~1 nm. The electrochemical performance of the as-prepared graphene is comparable to reduced graphene oxide in the determination of dopamine (DA) from the mixed solution of ascorbic acid, uric acid and DA. These results show that the decomposition of (NH4)2CO3 molecules in the EG layers under ultrasonication promotes the exfoliation of graphite and provides a low-priced route for large scale production of highly-quality graphene.
authors.forename: Yunwei
authors.initials: Y
authors.lastname: Wang
authors.forename: Xili
authors.initials: X
authors.lastname: Tong
authors.forename: Xiaoning
authors.initials: X
authors.lastname: Guo
authors.forename: Yingyong
authors.initials: Y
authors.lastname: Wang
authors.forename: Guoqiang
authors.initials: G
authors.lastname: Jin
authors.forename: Xiangyun
authors.initials: X
authors.lastname: Guo
mesh_terms: D001205:Ascorbic Acid / Q000032:analysis; D002254:Carbonates / Q000737:chemistry*; D004298:Dopamine / Q000032:analysis; D055664:Electrochemical Techniques; D004566:Electrodes; D006108:Graphite / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D056951:Photoelectron Spectroscopy; D012996:Solutions; D013059:Spectrum Analysis, Raman; D014465:Ultrasonics / Q000379:methods*; D014527:Uric Acid / Q000032:analysis; D014867:Water / Q000737:chemistry
chemical_list: D002254:Carbonates; D012996:Solutions; D014867:Water; D014527:Uric Acid; D006108:Graphite; C040502:ammonium carbonate; D001205:Ascorbic Acid; D004298:Dopamine