Electrocatalytic Reduction of Oxygen at Anthraquinonedisulfonate/Polypyrrole Composite Film Modified Electrodes and Its Application to the Electrochemical Oxidation of Azo Dye

Abstract

We report here the electrocatalytic reduction of oxygen on thin anthraquindisulfonate (AQDS)/poplypyrrole (PPy) composite film modified electrodes and its application to the electrooxidation of azo dye-amaranth. The polymercoated cathode exhibited good electrocatalytic activity towards oxygen reduction reaction (ORR), and allowed the formation of strong oxidant hydroxyl radical (. OH) in the medium via Electro-Fentons reaction between cathodically generated H 2 O 2 and added or regenerated Fe 2þ. The electrochemical behaviors of ORR in various pH solutions were described using cyclic voltammetry (CV), rotating disk electrode (RDE) and chronoamperometric (CA) techniques. The effect of solution pH on amaranth mineralization by the Fe 2þ /H 2 O 2 and Fe 3þ /H 2 O 2 electrooxidation systems was studied. In addition, the long-term electrocatalytic activity and stability of the AQDS/PPy composite film during multiple experimental runs were also examined electrochemically.

Electroactive and Sustainable Cu-MOF/PEDOT Composite Electrocatalysts for Multiple Redox Mediators and for High-Performance Dye-Sensitized Solar Cells

“…Meanwhile, the diffusion term is influenced by the Levich current obtained at different rotating angular velocities (ω). The Levich current was extensively used to find the number of electrons transferred ( n ) of an unknown reaction, the effective catalytic surface area ( A e ) of a mesoporous electrode, − and the diffusion coefficient ( D ) of new redox species, − based on a certain environment of the electrolyte with a known concentration ( C ) of redox species, kinematic viscosity ( ν ) of solvent, and Faraday constant ( F ). For one electrode, the electrode current-rotating angular velocity ( i –1 – ω –0.5 ) curve was applied to calculate the k 0 and A e values by the fitting line, as shown in Figure d, where the i –1 values were obtained at the formal potential ( E 0′ ) of I – /I 3 – at a certain electrode in accordance with the CV characteristics in Figure a. Compared to the bare PEDOT electrode, the composite Cu-MOF/PEDOT electrode exhibited a higher k 0 of 4.51 × 10 –3 cm –1 but a lower A e of 0.25 cm 2 (Table ).…”

“…38 Meanwhile, the diffusion term is influenced by the Levich current obtained at different rotating angular velocities (ω). The Levich current was extensively used to find the number of electrons transferred (n) of an unknown reaction, 39 the effective catalytic surface area (A e ) of a mesoporous electrode, 40−42 and the diffusion coefficient (D) of new redox species, 43−45 based on a certain environment of the electrolyte with a known concentration (C) of redox species, kinematic viscosity (ν) of solvent, and Faraday constant (F). (1)…”

Anion Effect on the Electropolymerization Reaction of Metanil Yellow in Aqueous Media and Characterization of Polymer Films

“…Metanil Yellow is a toxic material for animals and human beings having mutagenic properties therefore its degradation is also a significant research interest. Many publications are found concerning the chemical and electrochemical destruction of azo dyes especially Metanil Yellow [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24].…”