Amine ligand-based hydrothermal synthesis of Co3O4 nanoparticles, characterization and magnetic study

Cobalt(II,III) oxid (Co3O4) nanostructures have been successfully synthesized using [Co(NH3)(6)]Cl-3 and [Co(en)(3)]Cl-3 (en: ethylenediamine) as the single precursors via hydrothermal method, and CoCl2 center dot 6H(2)O through a facile ammonia-assisted approach. Indeed, ammine and en ligands, as well as ammonia vapor, act as the sources of hydroxide ion in the preparation of Co3O4 nanoparticles. The structure of products was confirmed by X-ray diffraction (XRD) technique and Fourier-transform infrared (FT-IR) spectroscopy and their morphologies were examined by scanning electron microscopy (SEM). The optical study of the as-prepared Co3O4 nanostructures using UV-Vis diffused reflectance spectroscopy (DRS) exhibited their semiconducting property by revealing one optical band gap in 3.3 eV. Moreover, the vibrating sample magnetometry (VSM) measurements showed a weak ferromagnetic behavior that could be attributed to uncompensated surface spins and/or finite-size effects. Further, the effects of the nature of the precursor, its concentration, temperature and reaction time on the size and morphology of the samples were studied in detail. (C) 2016 Elsevier B.V. All rights reserved.