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Reduction of Graphene Oxide by Polyphenols of Green Tea in the Presence of Oxidation of Transition Metals
Ghiasi Shirazi, Mohammad Amin | 2012
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- Type of Document: M.Sc. Thesis
- Language: Farsi
- Document No: 43855 (04)
- University: Sharif University of Technology
- Department: Physics
- Advisor(s): Akhavan, Omid
- Abstract:
- In this research, we have used green tea polyphenols as green reductants for reduction of graphene oxide. Furthermore, for the first time, the presence of some metals such as iron, tungsten and copper in the efficiency of reduction is investigated. XPS spectra indicate that iron can be considered as one of the best choices for helping polyphenols in the reduction process. Hence, we used AFM, XPS, Raman spectroscopy and I-V diagram to characterize graphene oxide reduced by polyphenols and iron. In recent years, hydrazine has been recognized as one of the standard reducing agents for effective reduction of graphene oxide. In our analysis, it is found that the conductivity of our reduced graphene is comparable to the graphene oxide reduced by hydrazine. Moreover, our reductant has two advantages: it is non-toxic and the resulting graphene suspension is more stable. Two mechanisms are proposed for the reduction of graphene oxide by green tea in the presence and absence of iron foil.
In addition to iron, tungsten, copper and other metals, we also investigated the presence of steel in the reduction process. It was observed that the reduction rate of graphene oxide in the presence of steel is much higher than the rate in the presence of iron. In the last chapter of this thesis, this phenomenon is studied and a mechanism for increasing the rate of reduction is proposed - Keywords:
- Graphene Oxide ; Reduction (Chemistry) ; Green Tea ; Polyphenols ; Chemical Exfoliation
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