Synthesis, characterization and biological evaluation of hexagonal wurtzite structured ZnO nanoparticle from Zn (II)-Schiff base complex

Studies on transitional metal compounds of Schiff base ligands have been of great significance due to their spectral properties and wide applications. Tetradentate Schiff base-Zn (II) complex was prepared and used as a precursor for the synthesis of Zinc oxide (ZnO) nanoparticles through a one-step calcination process at a different temperature: 250-350 °C. The influence of temperature on the antioxidant activities of synthesized nanoparticles was investigated. The precursor (zinc complexes) was characterized by melting point, thermogravimetric analysis, UV-Vis, FT-IR spectroscopy. elemental analysis, and thermogravimetric analysis (TGA) of tridentate Schiff base was synthesized and characterized using The structural studies of synthesized metal oxides were carried out with powder X-ray diffraction (PXRD), transmission electron microscopy (TEM), FTIR, and UV-visible. The energy band gap of the nanoparticles was 3.15 eV for ZnO@250, 3.31 eV for ZnO@300, while ZnO@350 was found as 3.17 eV and 3.56 eV. The average sizes of the ZnO nanoparticles were found to be around 25 nm. The antioxidant activities of the product were investigated through scavenging activity on DPPH. The obtained IC50 value of the DPPH activity for the product @ 350 °C (IC50 = 4.09 ± 0.32µM) was higher than other nanoparticles.