Synthesis Of Different Phases Of Nano Manganese Oxides And Their Dielectric Behaviour In Chitosan Composites

摘要

Nanoscale oxides of transition metals, particularly manganese, are desirable for many applications in designing electric, magnetic and heterogeneous catalytic materials. Manganese oxides exist in different phases, viz. MnO, MnO_2, Mn_2O_3, Mn_2O_7 and Mn_3O_4. Using different synthetic routes it is possible to synthesize different phases of manganese oxides. Moreover, composites of these oxides with polymer have the potential to address the needs of emerging dielectric technologies. In the present work, using manganese chloride and hydrazine hydrate, Mn_3O_4 and Mn_2O_3 nanoparticles were successfully synthesized by conventional and hydrothermal method respectively. The variation in the formation of the different phases has been discussed. The nanoparticles were well characterized by X‐ray Diffraction and using the Debye Scherrer formula, the average size of Mn_3O_4 and Mn_2O_3 nanoparticles were calculated to be 35 nm and 25 nm respectively. Using solution casting method, nanocomposites of chitosan/Mn_3O_4 were prepared and their electrochemical properties were studied using electrochemical impedance spectroscopy. It was observed that with increase in the content of nano oxides, the conductivity of the films increased. Also, the variation in the permittivity of these samples with respect to frequency was studied. The results suggest that the composites have a fair chance to be used in energy storage devices.