Removal of copper using chitosan beads embedded with amidoxime grafted graphene oxide nanohybids

This study explores a biopolymer-based composite system for metal decontamination of water using copper {Cu (II)} as a model pollutant. Novel composite beads of chitosan and amidoxime grafted graphene oxide (AOGO) were successfully prepared and used for the Cu (II) removal from aqueous solutions. For this purpose, acrylonitrile was first polymerized onto a gamma-irradiated and silanized graphene oxide substrate. The nitrile groups of polyacrylonitrile grafted graphene oxide (GO-g-PAN) were then chemically modified into amidoxime groups to form AOGO nanohybrids. These nanohybrids were mixed with a blend of chitosan (CS) and polyvinyl alcohol (PVA) and crosslinked using tetraethylorthosilicate (TEOS) to form composite CP/AOGO beads. Fourier transform infrared spectroscopy (FTIR) was used to study the structural changes at each step during the formation of composite beads. Scanning electron microscopic (SEM) analysis demonstrated that the beads had a well-developed spherical structure. The adsorption of Cu (II) onto CP/AOGO composite beads was studied under different conditions (initial concentration, pH, and contact time). The results revealed the potential of composite beads in copper removal from aqueous solutions.