High Electrocatalytic Behaviour of Ni Impregnated Conducting Polymer Coated Platinum and Graphite Electrodes for Electrooxidation of Methanol. (10th January 2017)

• Record Type: Journal Article
• Authors: Ali Shah, Anwar-ul-Haq; Yasmeen, Nabila; Rahman, Gul; Bilal, Salma
• Is Part Of: Electrochimica acta. Volume 224(2017)
• Page Start: 468
• Page End: 474
• Publication Date: 2017-01-10
• Subjects: Electropolymerization -- Nickel -- Polyaniline -- Poly(o-aminophenol) -- Methanol oxidation; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2016.12.085
• Languages: English
• ISSNs: 0013-4686

Abstract

Abstract: In this work nickel modified polymer composites have been synthesized electrochemically for methanol electrooxidation on platinum and graphite electrodes. Ni (II) ions were incorporated on polyaniline and poly (o-aminophenol)(PANI/POAP) bilayer structure from 0.1 M Nickel sulphate hexahydrate solution at open circuit potential (OCP).TheNi (II) deposited composites were characterized with Fourier Transform Infrared (FTIR) spectroscopy, Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS). Cyclic voltammetry characterization exhibits stable redox pair of Ni +3 /Ni +2 for both electrodes. Fourier transform infrared spectroscopy was used for functional group analysis. Ni (II) peaks were observed in the region of 400–700 cm −1 along with peaks at 1102 cm −1 and 1400–1600 cm −1 for polyaniline and phenoxazine units. The Ni-polymer composite on platinum and graphite electrode followed different phenomenon for methanol electroxidation in alkaline media. The cyclic voltammetry results showed significantly large methanol oxidation on platinum substrate with charge storage capacity of 196 μ F/cm 2 for 1.5 M methanol in alkaline media as compared to 8.306 μF/cm 2 of graphite. The diffusion controlled linear response for increase rate of methanol concentration has been obtained for Ni (II)/PANI/POAP-Pt. The electrochemical impedance spectroscopy (EIS)results indicated increase in charge storage capacity from 10 −4 F/cm 2 to 10 −3 F/cm 2 with increasing potentials at lower frequency region.The phase shift was observed from 60–40 degrees for increased potentials at low frequency range in EIS analysis. The increased conductive behavior from 10 −5 to 10 −2 s/cm 2 has been obtained fornickel modified polymer composite at higher frequency region in EIS analysis.