Potential of Silver Nanoparticles Functionalized Polyaniline as an Electrochemical Transducer

Abstract

Modification of commercial platinum (Pt) and glassy carbon (GC) electrodes with polyaniline (PANI) and silver nanoparticles doped polyaniline (PANI/Ag NPs) through electropolymerization of aniline in the absence and presence of Ag NPs in 1 M hydrochloric acid (HCl) was interrogated. Fourier transform infrared (FTIR) and transmission electron microscope (TEM) techniques were used for structural, compositional and morphological elucidation. FTIR spectra for PANI and PANI/Ag NPs had the characteristic PANI functional groups as well as desired bands for the conducting emeraldine (EM) form. The predominance of the PANI pattern in the spectra is indicative of the intact PANI structure in the presence of Ag NPs while the slight band shifts are signify interfacial interactions between PANI and Ag NPs. TEM micrograms depicts different size one dimensional nanofibric tubes of the supramolecular structures of PANI. Ag NPs functionalized PANI had larger smoother tubes, suggesting organized morphology arrangement. An increased energy dispersive spectroscopy (EDS)-TEM count from 256 to 277 confirms incorporation of Ag NPs in PANI. GC/PANI/Ag NPs exhibited outstanding electroactivity (higher conductivity and rate of electron transfer).This might be a result of the large surface coverage, film thickness and diffusion coefficient as a result of the large GC surface area. Possibly, the improvement might be due to the GC electrode properties. The electroactivity of the electrodes increased in the order: Pt < GC < Pt/PANI < Pt/PANI/Ag NPs < GC/PANI < GC/PANI/Ag NPs. The effect of Ag NPs in the polymer was demonstrated by ultimate band gap reduction of PANI and enhanced magnitudes of current response per electrode.