Facile synthesis and optical properties of Co3O4 nanostructures by the microwave route

Cobalt oxide (Co3O4) nanoplatelet shape like nanostructures have been successfully synthesized through a simple microwave route for the first time using cobalt acetate, NaOH and citric acid at 200 °C for 30 min. The structure and morphology of as-prepared Co3O4 nanoplatelets are characterized by means of powder X-ray diffraction (XRD), Fourier transform infrared spectrum (FTIR), and scanning electron microscope (SEM). XRD measurements indicate that the product has a perfect crystalline cubic phase of Co3O4 with a lattice constant a=8.082 Å. The SEM images show that the obtained Co3O4 nanopowder consists of nanoplatelets with diameter 125 nm and thickness 20 nm. Energy-dispersive X-ray spectroscopy (EDS) show that the composition of Co3O4 is stoichiometric. Room temperature photoluminescence measurement is exhibited by a strong UV emission and a suppressed green emission, confirming the good optical properties for the as-prepared Co3O4 nanoplatelets.