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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-22 1:26 |
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Conference: Bucharest University Faculty of Physics 2013 Meeting
Section: Physics and Technology of Alternative Renewable Energy Supplies
Title:
Few-layer graphenes obtained in supercritical fluids
Authors:
Catalin Ceaus , Adriana Balan , Stefan Marian Iordache, Ana Cucu, L. Popovici, A. Iordache, Ioan Stamatin
Affiliation:
University of Bucharest, Faculty of Physics,3Nano-SAE Research Center, 405 Atomistilor str., Bucharest-Magurele, 077125,Romania.
E-mail
catalin@3nanosae.org, andronie@3nanosae.org
Keywords:
graphene, supercritical fluids, Raman, ethanol, graphite.
Abstract:
Graphene has attracted a great deal of attention in the last years due to its unique properties such as high mechanical strength and electrical conductivity. There are some new methods for obtaining few layer graphenes from graphite. In this study, we report a supercritical processing technique for exfoliating expanded graphite. The starting material was graphite treated in supercritical mixture of ethanol-water with different ratio such as: 50/50, 80/20 and 100 % ethanol (v/v) at controlled temperature and time. Under supercritical fluid conditions the conversion of expanded graphite in multi-layer graphenes is possible due to the solvating power and high diffusivity of different SCFs such as ethanol, DMF and methanol. The obtained graphenes were analyzed by Raman spectroscopy, atomic force micoscopy (AFM) and SEM revealing placket structures with a single to a few layers (1-5) of graphene. Meanwhile, the electrochemical behavior showed that the obtained graphene have different responses showing a narrow double charge layer of ~100µC/cm2 and 2 reversible peaks on the oxidation and reduction wave at 750mV and 570mV respectively (in 0.1M HClO4). This report provides a simple and a low-cost approach for production of pure graphene sheets.
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