Promising EMI shielding effectiveness and anticorrosive properties of PANI-Nb2O5 nanocomposites: Multifunctional approach

Abstract

The present work highlights the suitability of polyaniline-coated niobium pentoxide (PANI-Nb2O5) nanocomposites as promising EMI shielding material with anticorrosion behavior. The structure, morphological, and stability features of the composites were characterized by using Fourier transforms infrared spectroscopy, scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDX), and thermogravimetric analysis (TGA). The characterization results indicate modified morphology and other physical properties confirm the formation of the PANI-Nb2O5 nanocomposites. The nanocomposites exhibit electromagnetic interference (EMI) shielding effectiveness in the range of – 27.7 to – 28.8 dB over the broadband frequency of 12–18 GHz covering the microwave Ku-band of practical relevance. The observed attenuation of ~ 99.88% has been found to be absorption dominant with absorbed EM power of 71–80.6% tunability with the varying concentration of Nb2O5 in PANI. Further, the corrosion inhibition response of the samples for mild steel (MS) was analyzed by atomic absorption spectroscopy (AAS), Tafel plot, and impedance spectroscopy and SEM techniques. Both AAS and Tafel plot studies indicate the adsorption property of PANI-Nb2O5 on MS in 5 M HCl solution with a mixed corrosion inhibitor response with both anodic and cathodic reactions. Impedance studies show that the charge transfer process provides MS corrosion protection and SEM topography obeys AAS, Tafel plots, and impedance results.