Synthesis of magnetic multi-walled carbon nanotubes/magnetite/chitin magnetic nanocomposite for the removal of Rose Bengal from real and model solution

Multiwalled carbon nanotubes (MWCNTs) were physically mixed with biopolymer chitin and magnetite to form a magnetic nanocomposite. The produced MWCNTS/chitin/magnetite (MCM) nanocomposite was characterized using scanning electron microscopy and surface-area analysis, and the magnetic properties were measured using a vibrating-sample magnetometer. The results revealed homogenous distribution of the chitin and magnetite nanoparticles within the MWCNTs in the MCM nanocomposite. The MCM nanocomposite was used to study the removal/adsorption of the well-known organic dye Rose Bengal (RB). The effect of different adsorption parameters was studied and optimized. The adsorption process was studied at different temperatures and the results were analyzed kinetically. Results revealed that the adsorption followed the pseudo-second-order kinetic model. Also, it was found that the adsorption of RB occurred in different steps including the diffusion of RB through the boundary layer to the external surface of the MCM nanocomposite, intraparticle diffusion, and adsorption of RB through the MCM nanocomposite particles. The adsorption was analyzed thermodynamically and results revealed spontaneity of the adsorption as the ΔG° value was negative and endothermic in nature as the ΔH° value was positive, and associated with the increase in the randomness as the ΔS° value was positive.