Inclusive analysis of Mn3O4 nanostructures: Dual-functional materials for dielectric and supercapacitor applications

Using extracts from medicinal plants, Mn₃O₄ microstructures were effectively created by a green synthesis method. The produced and pellet samples' structural and electrochemical characteristics were thoroughly examined. X-ray diffraction (XRD) investigation showed an estimated crystallite size of 39 and 43 nm with a prominent (211) orientation peak at 2θ = 36.1°, which corresponds to the tetragonal crystal structure of Mn₃O₄ with space group I4₁/amd(141)). Analysis using scanning electron microscopy (SEM) revealed an average grain size of roughly 500 nm. The presence of Mn–O bonds in the produced material was further validated by Raman spectroscopy. Within a temperature range of ambient temperature to 373 K, the impedance characteristics of the Mn₃O₄ samples were studied throughout a frequency range of 1 Hz to 1 MHz. The conductivity of electricity showed an Arrhenius-like increase with temperature, with an estimated activation energy of 0.39 eV and a conductivity value of 7.42 × 10⁻⁴ S/cm at 373 K. The dielectric characteristics, such as dielectric loss and dielectric constant, were assessed in the same frequency range and at temperatures between 303 and 373 K. The Mn₃O₄ nanostructures showed a specific capacitance of 284 F/g at a scan rate of 0.5 A/g in 1 M Li₂SO₄ aqueous electrolyte and a capacitive retention of 81 % even after 3000 cycles. According to these findings, the produced Mn₃O₄ nanoparticles show a great deal of promise for use in supercapacitors.