Graphene oxide porous crosslinked cellulose nanocomposite microspheres for lead removal: Kinetic study

In this study, highly porous adsorptive microspheres of graphene oxide (Go) crosslinked cellulose nanocomposites (GOCB) have been prepared based on GO and cellulose acetate (CA). The morphology, crystalline structure and molecular structure of the prepared nanocomposites were investigated using different analytical methods. The batch experiments were carried out for adsorption of Pb+2 onto the prepared nanocomposites. Lagergren's pseudo first-order, pseudo second-order, and intraparticle diffusion model, were used to evaluate the kinetic data in order to predict the mechanism involved in the adsorption process. Independent GO nanosheets are observed through TEM micrographs and it was clear that the addition of GO to the composites increases folding, roughness and groves that what would lead to increasing the surface area and consequently enhancing the adsorption capacities of the composites. The FTIR spectra of GOBC proved that there is a chemical interaction between GO and the cellulose chains via hydrogen bonding. The XRD pattern of graphite and GO revealed that the original graphite powders had almost been completely oxidized and GO has been exfoliated successfully. The analysis of kinetic models showed that the pseudo-first-order adsorption mechanism is predominant for GOCB and the rate-limiting step was physisorption in nature, where intraparticle diffusion is the rate-controlling mechanism.