Synthesis, characterization and photoluminescent properties of 3D nanostructures self-assembled with Mn3O4 nanoparticles

We report the hydrothermal-growth of 3D coins-like nanostructures self-assembled with single-crystalline tetragonal Mn3O4 nanoparticles using MnCl2 center dot 4H(2)O and KOH as raw materials. The morphology, composition and structure were characterized by field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) with selected area electron diffraction (SAED), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and Raman spectroscopy (RS). FESEM results show that the average diameter of coin-like nanostructures is 95 nm and the thickness is measured to be about 35 nm. TEM investigations reveal that the as-prepared Mn3O4 nanostructures are self-assembled with randomly distributed nanoparticles having a diameter of about 3 nm on the average. The photoluminescence (PL) studies for the as-prepared Mn3O4 nanostructures exhibit multiple PL emission bands located in the yellow-ultraviolet spectral region at room temperature without any surface modification.