Elaboration of modified poly(Ni II -DHS) films as electrodes by the electropolymerization of Ni(II)-[5,5′-dihydroxysalen] onto indium tin oxide surface and study of their electrocatalytic behavior toward aliphatic alcohols

Abstract

Please cite this article as: A. Ourari, B. Ketfi, L. Zerroual, Elaboration of modified poly(Ni II -DHS) films as electrodes by the electropolymerization of Ni(II)-[5, 5'-dihydroxySalen] onto indium tin oxide surface and study of their electrocatalytic behavior towards aliphatic alcohols, Arabian Journal of Chemistry (2014), doi: http:// dx.Abstract Nickel (II)-DHS Complex was obtained from N,N'-bis(2,5-dihydroxybenzylidene)-1,2-diaminoethane (H 2 DHS) ligand and nickel acetate tetrahydrated in ethanolic solution with stirring under reflux. This complex, dissolved in an alkaline solution, was oxidized to form electroactive films strongly adhered on the ITO (Indium tin oxide) electrode surface. In this alkaline solution, the poly-[Ni II -DHS]/ITO films showed the typical voltammetric response of (Ni 2+ /Ni 3+ ) redox couple centers which are immobilized in the polymer-film. The modified electrodes (MEs) obtained were also characterized by several techniques such as scanning electronic microscopy, atomic force microscopy and electrochemical methods. The electrocatalytic behavior of these MEs towards the oxidation reaction of some aliphatic alcohols such as methanol, ethanol, 2-Methyl-1-propanol and isopropanol was investigated.The voltammograms recorded with these alcohols showed a good electrocatalytic efficiency.The electrocatalytic currents were at least 80 times higher than those obtained for the oxidation of methanol on electrodes modified with nickel hydroxide films in alkaline solutions. We noticed that these electrocatalytic currents are proportional to the concentration of methanol (0.050 to 0.30 µM). In contrast, those recorded for the oxidation of other aliphatic short chain alcohols such as ethanol, 2-Methyl-1-propanol and isopropanol are rather moderately weaker. In all cases the electrocatalytic currents presented a linear dependence with the concentration of alcohol. These modified electrodes could be applied as alcohol sensors.

Electrocatalytic Oxidation of Methanol by a Polymeric Ni Complex-Modified Electrode Prepared by a One-Step Cold-Plasma Process

“…In addition, the preparation procedure is usually simple, and the properties of the resulting coating can be carefully controlled. Electropolymerization has been successfully used to deform electrode surfaces with Ni(II) cyclam and similar Ni(II) tetraazamacrocyclic complexes (Ourari et al, 2017 ) or Ni(II) tetramethyldibezotetraaza(14)anulene (Ciszewski et al, 2003 ), and the resulting films showed high catalytic activity for electro-oxidation of alcohols and/or other compounds that contain OH and NH 2 . In a previous paper (Bui et al, 2019 ), polymeric metal complexes with Cu, Fe, and Ni were prepared by an AC plasma process for detecting hydrogen peroxide.…”