Monodispersed fabrication and dielectric studies on ethylenediamine passivated α-manganese dioxide nanorods

• Monodispersed ethylenediamine (EDA) passivated α-MnO2 nanorods were fabricated by inexpensive wet chemical method.
• FTIR analysis indicated that surface passivation is strongly influenced by the introduction of the organic ligand.
• XRD and HR-SEM revealed the structure and morphology of the fabricated α-MnO2 nanorods with an average size of about 40 × 200 nm.
• Dielectric studies pointed out that the fabricated α-MnO2 is semiconducting in nature with resistivity, ρ = 1.46 to 5.76 × 103 Ωcm.
• The optical energy gap for the fabricated α-MnO2 nanorods is found to be around 1.37 eV.

In this present work, pure α-MnO2 nanorods were fabricated by the reduction of 0.2 m/L of KMnO4 with 0.2 m/L of Na2S2O3·5H2O and by passivating with the organic ligand Ethylenediamine (EDA). The structural, functional, morphological and chemical composition of the nanorods were investigated by X-Ray Diffractometer (XRD), Fourier Transform Infrared Spectrometer (FTIR), High Resolution Scanning Electron Microscope (HR-SEM) and Energy Dispersive X-Ray Spectrometry (EDX). The XRD analysis indicated high crystalline nature of the product and FTIR confirmed the contribution of the organic ligand in surface passivation. HR-SEM image revealed the morphology of the α-MnO2 nanorods with an average size of about 40 × 200 nm. EDX confirmed the presence of Mn and O in the material. UV–visible spectrophotometery was used to determine the absorption behavior of the nanorods and an indirect band gap of 1.37 eV was acquired by Taucplot. Dielectric studies were carried out using Broadband Dielectric Spectrometer(BDS) and the resistivity was found to be around the semiconductor range (ρ = 1.46 to 5.76 × 103 Ωcm).

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