Chemical reduction of an aqueous suspension of graphene oxide by nascent hydrogenElectronic supplementary information (ESI) available: Descriptions of graphene oxide synthesis and a photograph of graphene oxide reduction by nascent hydrogen, SEM images of nHRGOAl/NaOH before and after washing with diluted HCl solution and XRD patterns of nHRGOs. See DOI: 10.1039/c2jm30562c

• Main Authors: Pham, Viet Hung, Pham, Hai Dinh, Dang, Thanh Truong, Hur, Seung Hyun, Kim, Eui Jung, Kong, Byung Seon, Kim, Sunwook, Chung, Jin Suk
• Format: Article
• Language: English
• ISSN: 0959-9428; 1364-5501
• DOI: 10.1039/c2jm30562c

One of the major challenges in the chemical reduction of graphene oxide is increasing the C/O atomic ratio of the chemically converted graphene. In this paper, we report a simple and effective method to reduce aqueous suspensions of graphene oxide using nascent hydrogen generated in situ by the reaction between Al foil and HCl, Al foil and NaOH and Zn powder and NaOH. The nascent hydrogen-reduced graphene oxides (nHRGOs) were characterized by elemental analysis, UV-vis spectra, Raman spectra, X-ray photoelectron spectroscopy, thermogravimetric analysis and electrical conductivity measurements. The reduction efficiency of graphene oxide strongly depended on the reaction medium and the rate of nascent hydrogen generation. The best nHRGO achieved a C/O atomic ratio greater than 21 and a bulk electrical conductivity as high as 12 500 S m −1 , corresponding to the nascent hydrogen generated from the reaction between Al foil and HCl. Since nascent hydrogen could be produced on a metal surface upon oxidation in solution, other metals with low standard reduction potentials, such as Mg, Mn, and Fe, can be applied to reduce graphene oxide. Graphene oxide was reduced by nascent hydrogen that was generated in situ by the reaction of amphoteric metals with acid or base. The best nascent hydrogen reduced graphene oxide (nHRGO) achieved a C/O atomic ratio greater than 21 and a bulk electrical conductivity as high as 12 500 S m −1 .