Graphene oxide/chitosan-based composite materials as adsorbents in dye removal

Chitosan (Chit) is among the most widely used polysaccharides. Another material that draws attention with its unique physical and chemical properties is graphene oxide (GO). Reactive groups in the structure of both chitosan and graphene oxide make both materials ideal adsorbents. GO is an excellent adsorbent candidate with its large surface area and mechanical strength. However, the difficulty in recovering GO particles as an adsorbent creates a secondary environmental problem. Chitosan shows a weak interest in positively charged pollutants. The incorporation of GO into chitosan increases both the mechanical strength and adsorption capacity of the chitosan. The GO/Chitosan composite also offers the advantage of attracting both positively and negatively charged pollutants. Over the past five years, an increasing number of articles have been published reporting the use of GO/Chitosan-based composite materials as adsorbents in dye removal. The adsorption properties of GO/Chitosan-based composites appear to change with the inclusion of materials like magnetite, nano-metal, and other polysaccharides. It is seen that the differences in the preparation steps of composites of the same structure also affect their adsorption capacities. This paper aims to compile the works between January 2016 and December 2020 on GO/Chitosan-based composites, which were reported to remove dyes from wastewater.