Immobilization of chitosan nanolayers on the surface of nano-titanium oxide as a novel nanocomposite for efficient removal of La(III) from water

A novel nanocomposite has been designed and synthesized via surface crosslinking of chitosan nanolayers (NChit) with titanium oxide nanoparticles (NTiO2) using glutaraldehyde (Glu) as the crosslinking agent. A simple and green surface chemical reaction was accomplished by the aid of microwave heating process to enforce surface encapsulation and functionalization for the production of the aimed NTiO2-Glu-NChit nanocomposite. The average particles size of nanocomposite was characterized in the range of 52-58 nm using SEM and confirmed by the HR-TEM. The XRD, TGA and FTIR were also employed to assure the immobilization and crosslinking processes. NTiO2-Glu-NChit was studied to estimate the sorption efficiency towards La(III) from aqueous solution by the batch technique under different experimental controlling physicochemical parameters such as, initial pH of metal ion solution, contact time, nanocomposite dosage and initial metal ion concentration. The optimum sorption condition for La(III) as the target metal ion was identified at pH = 1.0, 3.0 and 6.0. The adsorption process of La(III) was characterized to follow the postulates of Langmuir and Freundlich isotherm models and the adsorption mechanisms were identified to obey the pseudo-second order kinetic model based on the best compatible results with the experimental data.