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.


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Aktekin, Burak; ÇAKMAK, GÜLHAN; Öztürk, Tayfur (2014-06-15)
A study was carried out into possibility of thermal plasma synthesis of Mg2Ni nanoparticles. Both prealloyed powders and elemental powders were used as precursors in an inductively coupled thermal plasma incorporating two injection probes located axially in the reactor one from the top and the other from the bottom. The study has shown that the use of prealloyed Mg2Ni as precursor leads to its disintegration in the plasma condensing into separate phases and therefore was not suitable for the synthesis of Mg...
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...
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...
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...
Palladium nanoparticles supported on chemically derived graphene: An efficient and reusable catalyst for the dehydrogenation of ammonia borane
Metin, Onder; Kayhan, Emine; Özkar, Saim; Schneider, Jorg J. (2012-05-01)
Chemically derived graphene (CDG) was prepared by hydrazine hydrate reduction of graphene oxide and used as support for palladium nanoparticles (Pd NPs) generated ex situ with controllable particle size and dispersion. The Pd NPs supported on CDG were well characterized by using a combination of advance analytical techniques and employed as catalyst in the dehydrogenation and hydrolysis of ammonia borane (AB) in organic solvents and aqueous solutions, respectively. Monodisperse Pd NPs of 4.5 nm were prepare...
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: