Continuous synthesis of graphite with tunable interlayer distance

Öztürk, Tayfur
A study was carried out to produce graphite with controlled interlayer distance synthesized from methane using hydrogen as modifying agent. The synthesis was carried out in radio frequency (r.f.) thermal plasma where the methane-to-hydrogen ratio varied systematically over a wide range. The synthesized materials were investigated in terms of structure, morphology and the interlayer distance. It is found that there is a critical fraction of hydrogen, around half of that of methane flow rate, up to which it is possible to control the interlayer distance as well as the number of layers making up the platelet in the synthesized material. The number of layers which were around 25 in the granular graphite obtained with methane only was modified into a flaky graphite of 10 mu m in size with as few as 12 layers yielding a surface area of 300 m(2)/g. The result combined with data from literature show that it is possible to adjust the interlayer distance in graphite from Lc = 0.334 to 0.369 nm even up to 0.416 nm. The significance of this was discussed within the context of the use of graphite as anode in rechargeable batteries.


Direct synthesis of hydrogen storage alloys from their oxides
Tan, Serdar; Öztürk, Tayfur; Aydınol, Mehmet Kadri; Department of Metallurgical and Materials Engineering (2011)
The aim of this study is the synthesis of hydrogen storage compounds by electrodeoxidation technique which offers an inexpensive and rapid route to synthesize compounds from oxide mixtures. Within the scope of this study, two hydrogen storage compounds, FeTi and Mg2Ni, are aimed to be produced by this technique. In the first part, effect of sintering conditions on synthesis of FeTi was studied. For this purpose, oxide pellets made out of Fe2O3-TiO2 powders were sintered at temperatures between 900 °C – 1300...
Hydrogen storage in magnesium based thin films
Akyıldız, Hasan; Öztürk, Tayfur; Özenbaş, Ahmet Macit; Department of Metallurgical and Materials Engineering (2010)
A study was carried out for the production of Mg-based thin films which can absorb and desorb hydrogen near ambient conditions, with fast kinetics. For this purpose, two deposition units were constructed; one high vacuum (HV) and the other ultra high vacuum (UHV) deposition system. The HV system was based on a pyrex bell jar and had two independent evaporation sources. The unit was used to deposit films of Mg, Mg capped with Pd and Au-Pd as well as Mg-Cu both in co-deposited and multilayered form within a t...
Flexible organic photovoltaics from zinc oxide nanowires grown on transparent and conducting single walled carbon nanotube thin films
Ünalan, Hüsnü Emrah; Kuo, Daniel; Parekh, Bhavin; Amaratunga, Gehan; Chhowalla, Manish (Royal Society of Chemistry (RSC), 2008-01-01)
The fabrication of flexible organic photovoltaics (OPVs) which utilize transparent and conducting single walled carbon nanotube (SWNT) thin films as current collecting electrodes on plastic substrates in zinc oxide nanowire (ZnO NW)/poly(3-hexylthiophene) (P3HT) bulk heterojunction photovoltaic devices is reported. The bulk heterojunctions for exciton dissociation are created by directly growing ZnO nanowires from solution on the SWNT electrodes and spin coating the P3HT polymer. A maximum OPV power convers...
Poly(ethylene terephthalate)/Carbon Nanotube Composites Prepared With Chemically Treated Carbon Nanotubes
Yesil, Sertan; Bayram, Göknur (Wiley, 2011-07-01)
Surfaces of multiwalled carbon nanotubes (CNT) were functionalized by treatment with strong acid mixture (purification) followed by modification with sodium dodecyl sulfate, poly(ethylene glycol) (PEG), and diglycidyl ether of Bisphenol A (DGEBA). Poly(ethylene terephthalate) (PET)-based conductive polymer composites were prepared by using these CNT by means of melt mixing with a twin screw extruder. Amount of carboxylic acid groups on the CNT surface increased after acid treatment but decreased with surfac...
Microwave-assisted ammonia decomposition reaction over iron incorporated mesoporous carbon catalysts
VARIŞLI, DİLEK; Korkusuz, Cansu; Doğu, Timur (2017-02-01)
Microwave-assisted ammonia decomposition reaction was investigated to produce COx free hydrogen, for fuel cell applications. Iron incorporated mesoporous carbon catalysts were prepared at different metal loadings, following an impregnation procedure. Mesoporous carbon acted as the catalyst support, as well as the microwave receptor. Complete conversion of ammonia was achieved at 450 degrees C over the catalyst having 7.7 wt% Fe, when the reaction was carried out in the microwave reactor system, using pure a...
Citation Formats
G. ÇAKMAK and T. Öztürk, “Continuous synthesis of graphite with tunable interlayer distance,” DIAMOND AND RELATED MATERIALS, pp. 134–139, 2019, Accessed: 00, 2020. [Online]. Available: