Diffusion, Adsorption and Electrode Kinetics of Electro-oxidatons on a Stationary Solid Electrode

BOZAL PALABIYIK B., KURBANOĞLU S., USLU B., ÖZKAN S. A., Zuman P.

ELECTROANALYSIS, vol.28, no.12, pp.2947-2955, 2016 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 28 Issue: 12
  • Publication Date: 2016
  • Doi Number: 10.1002/elan.201600372
  • Journal Name: ELECTROANALYSIS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.2947-2955
  • Keywords: Adsorption, diffusion, electro-oxidation, solid electrode, unusual i-E curves, PARKINSONS-DISEASE, DOPED-DIAMOND, SCHIZOPHRENIA
  • Ankara University Affiliated: Yes

Abstract

The i-E oxidation curves, obtained using a boron doped diamond electrode, for studies of oxidations of two piperazine derivatives ARIP (I) and PIRI (II), resulted in a sharp increase of current in the range of the oxidation potentials. After reaching a value, depending on concentration of I or II, the current remains practically constant up to +1.6 V. Such limiting currents i(1) are a linear function of concentrations and depend on the v(1/2). Hence it is diffusion controlled, shifts of the oxidation potentials indicate, that the monoprotonated forms are oxidized. At more negative potentials a limiting current i(2) occurs, due to the oxidation of the diprotonated form. Current i(2) increases with decreasing pH in a shape of a part of a dissociation curve. Diffusion control reflects the large size of molecules I and II. The two-electron oxidations yield a C=N bond in the piperazine ring. It seems to be the first reported diffusion controlled oxidation curves obtained on a stationary solid electrode.