Synthesis and characterisation of graphene oxide with magnetic nanoparticles

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Thesis Type: Postgraduate

Institution Of The Thesis: Gazi University, Fen Bilimleri Enstitüsü, Turkey

Approval Date: 2023

Thesis Language: Turkish

Student: Hande Hamiyet KONUK

Supervisor: Hüseyin Arbağ

Open Archive Collection: AVESIS Open Access Collection

Abstract:

In this master thesis study, the effects of the ratios of iron sources containing Fe2+/Fe3+ ions on the size distribution, magnetic properties, morphology and adsorption capacities of the magnetic nanoparticle-containing graphene oxide composite material were investigated. Graphene oxide materials were prepared by Modified Hummers method and Magnetic graphene oxide nanoparticles (MNGO) co-precipitation method in air atmosphere. Iron ion (Fe2+/Fe3+) source ratios were used as 2/3, 1/1 and 3/2. Characterizations of the prepared materials were carried out by XRD, ATR-FTIR, N2 Adsorption-Desorption, SEM, VSM and Zeta potential analyses. In XRD analysis results, graphene oxide and magnetite (Fe3O4) structures were successfully obtained in all MNGO composites. Different iron compounds were also detected in the composite structure at high Fe2+/Fe3+ source ratio. The size of the synthesized iron oxide nanoparticles was determined to be below 20 nm. This result shows that the particles have superparamagnetic properties. The results of VSM analysis showed that superparamagnetic iron oxide nanoparticles (SPIONs) were successfully obtained. In the adsorption studies of the materials, optimum conditions were determined by examining the effects of initial pH, dye concentration and operating temperature on dye removal in a batch system for the removal of methylene blue dye from aqueous solution. Adsorption mechanisms in dye removal were determined using Langmuir, Freundlich, Temkin and Henry adsorption isotherm models. Experimental data are compatible with the Langmuir isotherm model, and it was concluded that the adsorption processes take place in a single layer on homogeneous surfaces. The results show that MNGO composite materials are promising for dye removal studies.

Key Words : Magnetic nanoparticles, graphene oxide, methylene blue dye