Natural polysaccharides-modified graphene oxide for adsorption of organic dyes from aqueous solutions

Three polysaccharide- graphene oxide composite materials (PS-GO) were synthesized from graphene oxide (GO) and natural polysaccharides, which compounds were tested for removal of organic dyes from aqueous solutions. These adsorbents were characterized by Fourier transform infrared spectroscopy (FT-IR), Raman spectrometer, X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), N₂ adsorption-desorption isotherms and UV-vis spectrum. The adsorption properties of PS-GO towards four organic dyes were investigated along with measured effects on adsorption by initial concentration, temperature, contact time and pH value. Resulting adsorption isotherms, thermodynamics and kinetics were analyzed systematically. In these tests, PS-GO composite materials were found to be more efficient than as-prepared GO as adsorbents for the removal of both cationic and anionic organic dyes.