Effect of atomic percentage of Zn on the size and optical properties of porous ZnMn2O4 nanoparticles.

The porous ZnMn2O4 nanostructures have been synthesized by hydrothermal method by using Mn3O4 and Zn powder as precursors. The morphology of the nanoparticles could be tuned by changing the molar ratio of Zn in the reaction system. The final products have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis, UV-visible spectroscopy and the florescence spectrometer. Room temperature photoluminescence investigation indicates that the nanostructures have strong band-gap emission at yellow and orange bands. Absorption properties of ZnMn2O4 nanostructures indicated that the band gap energy varied with change in the atomic percentage of Zn in hetaerolite ZnMn2O4. The mechanism of this peculiar optical property was analyzed.