Biogenic ZnO/CuO/Fe2O3 Nanocomposite: A Groundbreaking Approach for Enhanced Degradation Capabilities and Reusability in Dye Removal Applications

Abstract

We present the successful synthesis of a biogenic ZnO/CuO/Fe2O3 nanocomposite using an aqueous leaf extract of Ocimum Basilicum L. The confirmation of biosynthesis was achieved through UV–Visible spectrophotometry (UV–Vis), which provided evidence of ZnO/CuO/Fe2O3 NC formation. Scanning Electron Microscopy further confirmed the nanoscale size of the NC, measuring at 65 nm. X-Ray Diffraction analysis revealed a hexagonal structure for ZnO and a monoclinic structure for CuO. The successful synthesis of the environmentally friendly ZnO/CuO/Fe2O3 NC was further verified using Fourier transformed infrared (FT-IR) spectroscopy, which identified the functional groups present in the composite. Notably, the ZnO/CuO/Fe2O3 NC demonstrated exceptional degradation capabilities for toluidine blue (TB), p-toluidine (PT), and m-Toluidine (MT), with degradation rates of 99%, 99.1%, and 99.7%, respectively, within a reaction time of 120 min. The reaction kinetics followed a pseudo-first order model, with rate constant (k) values of 0.0314 min−1 and 0.0189 min−1 for TB and PT, respectively. This high rate of dye degradation can be attributed to the low band gap of the NC, which was determined to be 1.44 eV for the indirect bandgap. Furthermore, the nanocomposite exhibited excellent degradation reusability, maintaining a high degradation rate in each cycle.