Electrochemical properties of composites of graphene-oxide and cobalt-ferrite doped with zink and gallium
| Autor: | Grujičić Marija B., Mravik Željko V., Bajuk-Bogdanović Danica V., Vengust Damjan, Jovanović Zoran M., Stojković-Simatović Ivana B., Jovanović Sonja M. |
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| Jazyk: | English<br />Serbian |
| Rok vydání: | 2022 |
| Předmět: | |
| Zdroj: | Tehnika, Vol 77, Iss 2, Pp 155-162 (2022) |
| Druh dokumentu: | article |
| ISSN: | 0040-2176 2560-3086 |
| DOI: | 10.5937/tehnika2202155G |
| Popis: | This paper presents the electrochemical properties of graphene-oxide composites and nanoparticles of cobalt-ferrite, as well as cobalt-ferrite doped with zinc and gallium. Graphene-oxide (GO) was synthesized by a modified Hummer's method. The magnetic nanoparticles were synthesized by the solvothermal method, after which the oleic acid was exchanged with dihydrocaffeic acid to obtain the hydrophilic material. Composites of graphene-oxide and magnetic nanoparticles were synthesized by the hydrothermal method, where the share of magnetic particles was 5 and 15 wt.% on graphene-oxide. The results of X-ray structural and FTIR analysis confirmed the complete oxidation of graphene layers. SEM and TEM analyzes showed deposition of magnetic nanoparticles on the graphene-oxide layer, without changing the size or shape of the nanoparticles. FTIR analysis of hydrothermally treated graphene oxide and composites showed that there is a partial reduction of epoxy groups, also a hydrogen bond is established between the components of the composite. Cyclic voltammograms show that the composites are stable at polarization rates of 5-400 mV s-1 , and that their capacity is predominantly pseudocapacitive in nature. Pseudocapacitance originates from the oxidoreduction reactions of H+ ions from electrolytes and surface functional groups of graphene-oxide. Based on the cyclic voltammograms, the specific capacities of all composites were calculated and the highest value being shown by the CFO_GO_15% composite, which is 36.86 F g-1 at a polarization rate of 5 mV s-1 . |
| Databáze: | Directory of Open Access Journals |
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