Abstract
A Co3O4 villiform nanostructure was prepared by the aid of the cobalt oxalate precursor and characterized with x-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscopy (SEM) and UV-vis spectrum. It is found that the villiform structure obtained consists of Co3O4 nanorods with diameters of 50–80 nm. Moreover, the UV-vis absorptions of the villiform Co3O4 show the apparent blue shifts by comparison with the bulk Co3O4, indicating a quantum size effect similar to the free Co3O4 nanoparticles.