Synthesis of Graphite Oxide from Kahatagaha Vein Graphite using a Localized Improved Hummers Method
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Date
2013
Journal Title
Journal ISSN
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Publisher
Uva Wellassa University of Sri Lanka
Abstract
In modern world, materials, - regardless of their make, whether natural or synthetic – play a
huge role. From all these materials, Graphite is taking a wide consideration of scientists as they
are naturally occurring, cheap material with very interesting physical, chemical and mechanical
properties. Within the range of applications of Graphite, Graphite Oxide (GO) and Graphene are
more important as they are having many applications and very good potential in Nano scale
materials and Nano Technology. GO has attracted much interest recently as a possible route for
the large scale production and manipulation of Graphene, a material with extraordinary
electrical properties. Sri Lanka has two major natural vein graphite deposits in Kahatagaha-
Kolongaha and Bogala. Of the two Kahatagaha vein graphite has the highest purity that can be
upgraded up to 99.97% Carbon by HCl leaching (Amaraweera et al, 2013). No researches and
experiments have been conducted on Kahatagaha vein graphite which has been upgraded up to
99.97% Carbon in nano scale. The potential for value addition to Kahatagaha graphite has not
yet been adequately explored. This study aims at synthesizing GO using a localized version of
the Improved Hummers Method and characterization of GO to confirm the oxidation.
Methodology
Graphite sample, KNPG (Kahatagaha Needle-Platy Graphite) was first crushed using a hammer
to obtain +10 mm chips and then the sample was milled in a disc mill for 15 minutes. The
milled sample was sieved using a sieve shaker and <53 microns portion was taken for further
treatments.
675 ml of 5% HCl was added to 50 g of graphite in 1000 ml beaker and it was vigorously stirred
for 1.5 hours at 60 C. The solution was vacuum filtered and washed with distilled water (500
ml) and the same procedure was repeated once. Finally purified graphite was washed until the
pH become neutral. KNPG achieved purity level of 99.97% Carbon.
9: 1 mixture of conc. H2SO4 (96% 360 ml) and conc. H3PO4 (85% 40 ml) were added to a
mixture of 3 g of purified KNPG and 18 g of KMnO4. The mixture was stirred for 6 hours at
50 C. Then the solution was poured on to ice (200 ml) with 30% H 2O2 3 ml and then vacuum
filtered through Fisherbrand filter paper. The brown product left on the filter paper was
collected and washed with water (200 ml x 3) and left in a vacuum drier at 105 C for 2 hours.
The hard black solid taken out from the vacuum drier was crushed using an agate mortar and
pestle to obtain finer particles of 6.86 g of GO.
A pellet for electrical conductivity measurements was made using 1g of GO and FTIR Spectrum
for GO was taken. A tape was casted using GO for sheet resistance measurements and XRD
spectrum was obtained for characterization of GO.
Description
Keywords
Mineral Sciences, Mineral, Materials Sciences, Graphite Industry, Graphite, Science and Technology