Well-Crystalline ZnO Nanostructures for the Removal of Acridine Orange and Coomassie Brilliant Blue R-250 Hazardous Dyes

In the present study, attempt has been made to synthesize ZnO nanomaterials using cationic surfactant viz. Cetyltrimethylammonium bromide at relatively low temperature. The prepared nanomaterials were characterized by UV-visible spectroscopy, XRD, FTIR and TEM measurements. Different morphologies of ZnO nanomaterials (rod, flower and spherical) have been attained by varying the reaction conditions. These nanomaterials have been used for the adsorption of cationic dye (Acridine orange) and anionic dye (Coomassie Brilliant Blue R-250) from their aqueous solution. Maximum adsorption of the two dyes has been attained by spherical shape nanoparticles, as the size of spherical nanoparticles is relatively smaller than the other morphologies. Batch mode experiments have been performed for both the dyes to study the effect of adsorbent dose, pH, and contact time on different dye concentrations. Langmuir and Freundlich adsorption isotherms have been studied to explain the interaction of the dyes. The experimental data indicates that the adsorption rate follows pseudo-second-order kinetics for the removal of both the dyes. Moreover, the ZnO nanoparticles and the adsorbed dyes were desorbed. The identities of recovered nanoparticles as well as both the dyes have been found to be same and were reused.