Preparation And Characterization Of Graphene Oxide Cross-Linked Composites

Graphene oxide (GO)-based materials have been studied for applications in adsorption and water treatment. Experimental results revealed that GO is a promising adsorbent due to its low-cost production, large surface area, and strong interaction with a wide range of dyes in an aqueous phase. GO chemical structure has the potential to be tuned using chemical methods such as cross-linking to produce a framework material. Therefore, in this study, cross-linking of GO structure using chitosan biopolymer as a cross-linker agent was investigated. Cross-linked GO composites were prepared through a green solution-based chemistry approach. Chemical structural, morphological and thermal changes in the cross-linked GO composites were investigated using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and thermal gravimetric analysis (TGA). Also, adsorption properties of samples were obtained using methylene blue (MB) as a cationic probe, in solution phase. According to the spectroscopy results, cross-linked composites suggested interaction between the GO sheets with chitosan through the formation of amide linkages. SEM results showed irregular layer shapes connected to each other with higher surface roughness and porosity in cross-linked samples. Changes in the thermal stability of cross-linked samples can be ascribed to the cross-linking effect. Kinetic adsorption studies indicated higher sorption capacity of cross-linked samples toward MB in aqueous phase compare to pure GO and chitosan.