Çevre uygulamaları için grafen oksit esaslı aerojellerin geliştirilmesi

In order to cope with increasing water pollution due to crude oils, petroleum products, organic solvents, and dyes, it is urgent to come up with feasible and economical solutions. Due to their large surface area, abundant functional groups and tunable properties, graphene oxide (GO) based aerogels are promising candidates for pollutant removal. In the scope of this thesis study, it was aimed to produce GO-based aerogels with high reusability performance and removal capacity to be used in environmental applications. GO was synthesized by the Tour method and characterized with ATR-FTIR, TGA and UV-vis. GO aerogels, reduced GO-stearic acid-based (rGO/SA) aerogels and GO-(3-Aminopropyl)triethoxysilane aerogels (GO-NH2) were prepared. Analysis of the porous structures of produced aerogels was conducted by using SEM. ATR-FTIR analysis was performed for the chemical characterization of the aerogels, and TGA was performed to evaluate their thermal properties. The pollutant removal performance of aerogels was compared using chloroform, sunflower, methylene blue (MB) and methyl orange (MO). rGO aerogels exhibited an absorption capacity of 155 g/g for chloroform while rGO/SA aerogels exhibited 87 g/g. However, rGO/SA aerogel maintained its original absorption capacity even after 15 cycles, unlike rGO aerogels, which exhibited a sharp decrease after the 1st cycle. Meanwhile, the parameters affecting the adsorption capacity of GO and GO-NH2 aerogels toward dyes, such as initial concentration and pH, contact time, temperature and dye charge, were investigated. Adsorption kinetics and isotherms were also examined for MB and MO. GO and GO-NH2 were found to have maximum adsorption capacities of 588 mg/g and 118 mg/g for MB and MO, respectively, as calculated from the Langmuir isotherm. The kinetic study revealed that adsorption of MB on GO aerogels followed the pseudo-first-order model while the adsorption of MO followed the modified Freundlich model. Van't Hoff equation used to calculate thermodynamic parameters indicated that the adsorption process of MB onto GO aerogels was endothermic and spontaneous. Recyclability and reusability studies on GO aerogels for MB adsorption were also conducted. Aerogels could easily be recycled and reused, and they were able to maintain over 90% removal capacity after ten cycles.