Synthesis, Characterization and Optical Properties of Co3O4 Nanoparticles

Mononuclear acyclic cobalt(II) complex [CoL](NO3)2, with the L = 3,3ʹ-dimethoxy-2,2ʹ-(propane-1,3-diyldioxy)dibenzaldehyde was synthesized and used as a precursor for preparation of the Co3O4 nanoparticles. The method was based on thermal decomposition of the cobalt(II) complex at 450 ºC for 3 h in air atmosphere. The cobalt oxide nanoparticles were characterized using FT-IR, UV-Vis, XRD, SEM, and TEM techniques. The FT-IR and XRD results revealed that the Co3O4 nanopartcles were pure cubic and single phase. TEM image proved the formation of weakly agglomerated Co3O4 consisted of uniformaly shaped nanoparticles. The average particle size of the obtained Co3O4, derived from transmission electron microscopy data was approximately 17 nm, which is in agreement with that calculated by XRD. In addition, the optical spectrum indicated one direct band gap at 2.3 eV.