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Electrocatalytic Reduction of Dioxygen at the Surface of Carbon Paste Electrodes Modified with 9,10‐Anthraquinone Derivatives and Dyes
Author(s) -
Manisankar Paramasivam,
Gomathi Anandhan
Publication year - 2005
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.200403213
Subject(s) - cyclic voltammetry , chronoamperometry , chemistry , inorganic chemistry , anthraquinone , overpotential , electrode , electrocatalyst , carbon paste electrode , electrochemistry , voltammetry , carbon fibers , materials science , organic chemistry , composite material , composite number
Abstract The modified carbon paste electrodes were constructed by the incorporation of 9,10‐anthraquinone derivatives and dyes in a graphite powder‐paraffin oil matrix. Their electrochemical and catalytic behavior were investigated by cyclic voltammetry and chronoamperometry techniques. The stability of the modified carbon paste electrodes was studied by cyclic voltammetry in acidic, neutral and basic media. The electrocatalytic ability of the modified electrodes for the reduction of dioxygen to hydrogen peroxide was examined and pH 7.0–8.0 was chosen as the optimum working pH by comparing the shift in oxygen reduction potential. The anthraquinones incorporated carbon paste electrodes possess excellent electrocatalytic abilities for dioxygen reduction with overpotential ranging from 438 to 570 mV lower than at a pure carbon paste electrode. Hydrodynamic voltammetric studies were performed to determine the mass specific activity of the anthraquinones used, heterogeneous rate constants for the reduction of O 2 at the surface of the modified electrodes and the apparent diffusion coefficient of O 2 in buffered aqueous O 2 ‐saturated solutions. In addition, the diffusion coefficients of modifiers in paraffin oil were also evaluated. Studies showed the involvement of two electrons in dioxygen reduction.