Investigation of the Nature of Functional Groups of Graphene Membranes by Means of IR Spectroscopy
M. A. SEITZHANOVA1, S. A. YASHNIK2, Z. R. ISMAGILOV3, S. R. KHAIRULIN2, Z. A. MANSUROV1,4, A. A. MONTAYEVA5
1Al-Farabi Kazakh National University, Almaty, Kazakhstan
2Boreskov Institute of Catalysis, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
3Federal Research Centre of Coal and Coal Chemistry, Siberian Branch, Russian Academy of Sciences, Kemerovo, Russia
4Institute of Combusion Problems, Almaty, Kazakhstan
5School-Gymnasium No. 136 named after M. Dulatov, Almaty, Kazakhstan
Keywords: graphene, graphene oxide, rice husks, membrane, IR spectroscopy
Pages: 480-486
Abstract
Graphene membranes were manufactured for the purpose of developing efficient materials for the membrane technologies of water freshening. Investigation of the nature of their functional groups was carried out by means of IR spectroscopy. Graphene membranes were obtained using two methods: 1) vacuum filtration; 2) immersion precipitation. Graphene materials used in the study were graphene oxide (a commercial sample) and graphene (a laboratory sample obtained by means of stepwise carbonization of rice husks). The data of the FTIR spectra of diffuse reflection (DRIFT) from membranes manufactured using graphene point to the low defect content in its single-layer graphite structure, while membranes based on graphene oxide contain not only graphene layers but also amorphous carbon with sp 3-hybridized atoms and oxygen-containing functional groups (mainly carboxylic and phenolic). The tests of the membranes were carried out with respect to the efficiency of filtration of salt-containing solutions (NaCl, KCl, MgCl2, CaSO4 и MgSO4) and salt removal. Analysis of desalinated solutions by means of atomic absorption flame emission spectrophotometry showed that purification efficiency was 74-80 % for membranes obtained by means of vacuum filtration.
DOI: 10.15372/CSD20202550
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