Synthesis and adsorptive characteristics of novel chitosan/graphene oxide nanocomposite for dye uptake

A green approach was utilized to synthesize crosslinked chitosan-based graphene oxide (GO) nanocomposite membrane using tetraethyl orthosilicate (TEOS) as a crosslinking agent. The structural analysis of the membranes was investigated using infrared (IR) spectroscopy. The porosity and morphology of membranes were examined using scanning electron microscopy (SEM) and BET (Brunauer-Emmett-Teller) techniques. The SEM micrographs revealed that GO was uniformly mixed in chitosan matrix. BET results further confirmed that the inclusion of GO led to increase the surface area of the nanocomposite which also improved its adsorptive properties. Congo red (CR) dye was used to study the adsorption efficiency of developed membrane. The effect of time, pH and dose rate on the adsorption behavior of developed membrane was investigated. The maximum loading capacity of CR on CS/GO membrane was 175.9 mg/g. The kinetics and equilibrium isotherms were well described by pseudo-second-order and Langmuir isotherm models respectively. The high adsorption efficacy and green nature of the nanocomposites provide a good alternative to already existing petroleum based (biostable) membranes.