Photoremediation of methylene blue by biosynthesized ZnO/Fe3O4 nanocomposites using Callistemon viminalis leaves aqueous extract: A comparative study

• Published in: Nanotechnology reviews (Berlin) 2021-11, Vol.10 (1), p.1912-1925
• Main Authors: Dwivedi, Poonam, Jatrana, Indu, Khan, Azhar U., Khan, Azmat Ali, Satiya, Honey, Khan, Masudulla, Moon, Il Soo, Alam, Mahboob
• Format: Article
• Language: English
• Subjects: Acetic acid; Biosynthesis; Callistemon viminalis; Comparative studies; Crystallites; Crystals; Differential thermal analysis; Differential thermogravimetric analysis; Electron microscopy; Ferric chloride; Fourier analysis; Fourier transforms; Heterojunctions; Infrared spectroscopy; Iron oxides; Irradiation; Leaves; Light irradiation; Methylene blue; Microscopy; Nanocomposites; Nanoparticles; Phenolic acids; Phenols; Photodegradation; Photoelectron spectroscopy; Photoelectrons; Plant extracts; Polyphenols; Scanning electron microscopy; Stability analysis; Stabilizers (agents); Thermal analysis; Thermal stability; Transmission electron microscopy; XPS; Zinc acetate; Zinc oxide; ZnO/Fe; zno/fe3o4 nanocomposites
• ISSN: 2191-9089; 2191-9097
• DOI: 10.1515/ntrev-2021-0117

This article reports a simple, cost-effective, and eco-friendly biosynthesis of ZnO/Fe nanocomposites using leaves’ water extract. For the first time, we used a green synthetic route leaves’ extract to prepare ZnO/Fe nanocomposites (NCs) using zinc acetate and ferric chloride as precursor materials. Fourier transform infrared (FTIR) spectroscopic results revealed polyphenolic compounds mainly phenolic acids present in the plant extract acted as both reducing and stabilizing agents to synthesize ZnO/Fe NCs. Outcomes of XRD and X-ray photoelectron spectroscopy confirmed the formation of ZnO–Fe heterojunction in ZnO/Fe NCs, with crystallite sizes of 45, 35, and 60 nm, respectively, according to Debye–Scherrer’s formula. EDX confirmed Zn, Fe, and O in the ZnO/Fe nanocomposite. Scanning electron microscopy and transmission electron microscopy (TEM) analyses revealed the existence of both ZnO and Fe in the NCs with some agglomeration. The thermal stability of NCs was evaluated using thermogravimetric analysis (TGA) and differential thermal analysis (DTA) in a nitrogen atmosphere. In addition, as-prepared ZnO/Fe NCs along with biosynthesized ZnO and Fe (prepared by extract) nanoparticles were examined for photodegradation of methylene blue under visible light irradiation for 150 min. The result reveals that the photodegradation efficiency of ZnO/Fe NCs (99.09%) was higher compared to that of monometallic ZnO (84.7%) and Fe (37.1%) nanoparticles.