Author/Authors :
Karimi-Sabet، J نويسنده 2NFCRS, Nuclear Science and Technology Research Institute, Tehran, Iran , , Hadi، A نويسنده Department of Chemical Engineering, Faculty of Engineering, University of Tehran, Tehran, Iran , , Moosavian، S.M.A نويسنده Department of Chemical Engineering, Faculty of Engineering, University of Tehran, Tehran, Iran , , Ghorbanian، S نويسنده Department of Chemical Engineering, Faculty of Engineering, University of Tehran, Tehran, Iran ,
Abstract :
After fullerene and nanotubes, graphene is a new allotrope of carbon. This
attractive nanomaterial can be produced by different methods. In this work,
we have used the less common approach for preparation of graphene. This
technique is based on the utilization of supercritical fluid. Ethanol was used
as the solvent for exfoliation of pristine graphite, at the temperature of 400
oC and pressure of 40 MPa. In addition, supercritical ethanol was used to
reduce and exfoliate graphite oxide. FT-IR spectra indicate that reduction
and exfoliation of graphite oxide can be done in supercritical ethanol,
simultaneously. Effect of graphite oxidation on the yield and quality of
graphene was investigated and results showed that oxidation of graphite can
improve the yield of supercritical process from 12.5% to 26.8%, but Raman
spectra revealed that quality of graphene samples produced by graphite
oxide is lower than neat graphite. Moreover, the impacts of initial graphite
concentration and sonication power on the exfoliation yield were studied.
Finally, hybrid structure of graphene and titanium dioxide nanoparticles
were prepared by ultrasonic method and used for photocatalytic degradation
of methylene blue dye pollutant. Results revealed that titanium dioxide
nanoparticles show better photocatalytic performance in presence of
graphene sheets.
