Investigation of the effect of annealing temperature on photophysical properties of manganese dioxide nanostructure prepared via co-precipitation route

Abstract

Co-precipitation method was used to synthesize Manganese dioxide (MnO2) nanostructures. The synthetization of Manganese dioxide (MnO2) requires Manganese dichloride tetrahydrate (MnCl2.4H2O), Sodium hydroxide (NaOH) and distilled water. Manganese dioxide nanostructures were synthesized by taking suitable amount of manganese dichloride tetrahydrate and mixing it with 100 mL of distilled water. Sodium hydroxide (NaOH) was added into the precursor solution to adjust pH 12 and stirred for 18 hours. The prepared MnO2 nanoparticles were characterized through various techniques such as X-ray diffraction (XRD), UV-visible spectroscopy and scanning electron microscopy (SEM). XRD results revealed that MnO2 had tetragonal single phase. Average crystallite size for prepared samples is found in the range 39 to 45 nm. It is increased with increasing of annealing temperature. Volume and density of unit cell are found to be 258.83 Å3 and 4.522 g/cm3 respectively. SEM results showed that the annealing temperature has affected the shape of MnO2. The morphology of MnO2 changed from spherical to rod-like shape as annealing temperature increase. Absorption peaks are obtained between 362 nm to 366 nm of wavelength. These Manganese dioxide (MnO2) nanoparticles can be applied as catalysts, permeable of toxic metals, ion/molecular-sieves, component of dry cell, inorganic pigment, electrodes for electrochemical batteries, electrodes for supercapacitors and cleaning of water.