Synthesis and Characterization of Cobalt Oxide Nanoparticles

In this paper, thermal decomposition of the [Co(NH3)5(H2O)](NO3)3 complex was investigated under solidstate conditions. The obtained results showed that this complex was easily decomposed into the Co3O4 nanoparticles atlow temperature (175 °C) without using expensive and toxic solvents or complicated equipment. The product wasidentified by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), transmission electronmicroscopy (TEM) and energy-dispersive X-ray spectroscopy (EDS). FT-IR, XRD and EDS analyses confirmed theformation of highly pure spinel-type Co3O4 phase with cubic structure. TEM images showed that Co3O4 nanoparticleshave a sphere-like morphology with an average size of 10-30 nm. The optical spectrum of each Co3O4 product revealedthe presence of two band gaps in the range of 2-3.5 eV, which in turn confirmed the semiconducting properties. Themagnetic measurement showed a weak ferromagnetic order at room temperature. Photocatalytic degradation of methylorange demonstrated that the as-prepared Co3O4 nanoparticles show good photocatalytic effect under visible-lightirradiation.

کلیدواژه ها:

Metal oxides ، Co3O4 nanoparticles ، Thermal decomposition ، pentamminecobalt(III) complexes ، Ferromagnetic order