Plasma Treatment of Graphites G100 and G300
High-surface area graphite (HSAG) is obtained from thermal treatment of carbon black. This material is produced under the trademark TIMREX(r). This study investigates the effects of low-pressure oxygen plasma treatments on two types of HSAG.
The results show that plasma treatment increases the BET surface area of graphite and decreases the SBET with increasing plasma exposure time. This study also presents information about the structural and mechanical properties of both graphite samples. X-ray diffractograms were recorded on a Bruker D8 Advance diffractometer.
The BET apparent surface area for G100 was 0.42 cm3.g-1. The total pore volume was 0.19 cm3.g-1. The carbon content was higher in the G100 sample than the G300 sample. The G100 sample had a more oxidized composition compared to the G300 sample. The carbon content in the G300 sample did not change after three minutes of plasma exposure.
A Raman spectroscopy profile of G100-10 is similar to that of HOPG. The D, G, and 2D bands are the most prominent. The line-shape reported is slightly asymmetric on the lower wavenumber side. The D band is centered at 1610 cm-1. The G band downshifts by 3.0 cm-1 closer to highly-oriented pyrolytic graphite. The D' mode is active to a lesser extent.
The D and G bands show overlapping desorption peaks over a wide temperature range. The carboxylic acid peak overlaps with the peroxide peak. These results indicate the presence of hydroxyl groups. The presence of these hydroxyl groups is likely attributed to the increased oxide content of the G300 sample.
