THE REDOX BEHAVIOR OF ELECTROLESS NI/PTFE DEPOSITS IN KOH

The Ni(II) and higher valence states redox behavior of Ni and Ni/PTFE deposited electrodes fabricated by electroless plating are compared using cyclic voltammetry and potentiodynamic techniques, for their ability to evolve O2 and oxidize ethanol in 1 mol dm-3 KOH. In this study, a Ni/PTFE electrode formed in a 6 g dm-1 polytetrafluoroethylene (PTFE) containing plating bath demonstrates the highest activity An examination of the surface morphology of this Ni/PTFE deposit demonstrates that the highest activity of this electrode is not caused by the enhanced surface area of the Ni/PTFE electrode. The presence of PTFE in a Ni electrode alters the formation pathway of gamma-phase Ni hydrous oxide. Gamma-phase Ni hydrous oxide catalyzes O2 evolution, while an intermediate species/structure between beta-NiOOH and gamma-NiO2 is responsible for the oxidation of ethanol.