Green Synthesis of ZnO Nanoparticles for Efficient Cr(VI) Removal and Antioxidant/Microbial Properties

Abstract

AbstractThe study focuses on fabrication of a cost‐effective Zinc Oxide nanoparticles (ZnONPs) adsorbent using Syngonium podophyllum leaves extract to remove hexavalent chromium (Cr6+) from synthetically prepared wastewater. Various spectroscopic techniques, including X‐ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X‐ray analysis (EDX), and transmission electron microscopy (TEM), were used to characterize the ZnONPs. Fourier infra‐red spectroscopy (FTIR) detected that various organic compounds like flavonoids, terpenoids, and carboxylic acids acts as stabilizing and capping agent. The batch adsorption study was conducted to investigate the effects of Cr6+ adsorption time, pH, adsorbent concentration, and initial adsorbate concentration. The maximum adsorption capacity was 267.068 mg/g at 313 K. The Freundlich isotherm model was most suitable, indicating multilayer confiscation of Cr6+ on the heterogeneous surface. Chemisorption was identified as the mechanism of sequestration. Thermodynamic studies revealed that Cr6+ removal was spontaneous and feasible, with ΔG° values suggesting predominantly physisorption. Additionally, ZnONPs displayed strong antibacterial activity against S. aureus bacteria, making them a potential alternative to antibiotics. ZnONPs exhibited impressive antioxidant activity. Overall, ZnONPs synthesized through biosynthesis proved to be excellent nano‐sorbents, antioxidants, and biocompatible materials with promising applications in water remediation and healthcare.