Novel biocompatible composite (Chitosan–zinc oxide nanoparticle): Preparation, characterization and dye adsorption properties

In this paper, the preparation, characterization and dye adsorption properties of novel biocompatible composite (Chitosan–zinc oxide nanoparticle) (CS/n-ZnO) were investigated. Zinc oxide nanoparticles were immobilized onto Chitosan. Physical characteristics of CS/n-ZnO were studied using Fourier transform infra-red (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and wavelength dispersive X-ray spectroscopy (WDX). Two textile dyes, Direct Blue 78 (DB78) and Acid Black 26 (AB26), were used as model compounds. The effect of CS/n-ZnO doses, initial dye concentration, salt and pH were elucidated at 20 ± 1 °C. The isotherm and kinetics of dye adsorption were studied. The presence of functional groups such as hydroxyl, amino and carbonyl groups were detected. Results showed zinc oxide nanoparticles were immobilized onto Chitosan. The data were evaluated for compliance with the Langmuir, Freundlich and Tempkin isotherm models. It was found that AB26 and DB78 followed with Langmuir and Tempkin isotherms, respectively. In addition, adsorption kinetics of both dyes was found to conform to pseudo-second order kinetics. Based on the data of present investigation, one could conclude that the CS/n-ZnO being a biocompatible, eco-friendly and low-cost adsorbent might be a suitable alternative for elimination of dyes from colored aqueous solutions.