Preparation of ZnO Nanoparticle Additive Biocomposites and Investigation of Their Heavy Metal Removal Potential

Abstract

Recently metalnanoparticles embedded in porous biocomposite materials have played an important role in various fields such as catalyst supports, sensors, energy storage and adsorption applications. In this study, biocomposites synthesized with different proportions of starch, clay and polyethylene glycol (starch/clay/PEG20000) were combined with ZnO particles prepared by green synthesis with Malva sylvestris extract. The ZnO-doped biocomposites synthesized for the first time in this study were characterized by FT-IR, XPS, SEM, TGA and BET analyzes. As a result of the characterization processes, it was found that the thermal stability and surface area increased with increasing clay content in the composites. Accordingly, the KPEG-ZnO composite with the highest surface area and porosity was selected as the adsorbent for the removal of Cr(VI) ions from aqueous solutions. Optimal adsorption conditions (t= 45 min, pH= 2.0, C<inf>0</inf>= 50 mg/L, adsorbent dose= 1.0 g/L) were determined for the adsorption process. It was also found that the pseudo-second order kinetic model for adsorption kinetics and Langmuir's isothermal model for adsorption equilibrium data were more appropriate. The maximum adsorption capacity of Cr (VI) for KPEG-ZnO was found to be 145.8 mg/g. The experimental results showed that the KPEG-ZnO composite is an environmentally friendly, inexpensive and readily available adsorbent for the removal of Cr (VI) ions from aqueous solutions. © 2025, Gumushane University. All rights reserved.