ISSN:
1572-8838
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Electrical Engineering, Measurement and Control Technology
Notes:
Abstract Poly(4-vinylpyridine) (PVP) has been used to modify ordinary pyrolytic graphite (OPG) electrodes with adsorbed cobalt tetra-sulphonated phthalocyanine (CoTsPc) in acid solutions. These modified electrodes were prepared in different manners and characterized by cyclic voltammetry. Their electrocatalytic activity for oxygen reduction and stability in 0.05M H2SO4 solutions was examined at room temperature. The OPG/CoTsPc/PVP modified electrodes were found to be more active for oxygen reduction in 0.05M H2SO4 solutions as compared to the electrode with adsorbed CoTsPc on OPG without PVP. The increase in activity is due to the formation of an adduct between PVP and CoTsPc. U.v.-visible and FTIR studies provide evidence for such adduct formation. Over a 10 h period the activity of the OPG/CoTsPc/PVP system was essentially constant while that of OPG/CoTsPc without polymer decreased by a substantial amount (about 37%). The PVP layer inhibits the diffusion of the CoTsPc and/or Co out of the complex into the solution phase. The stability of the OPG/CoTsPc/PVP system may also be due to low solubility of the adduct between PVP and CoTsPc in a 0.05M H2SO4 solution. Thicker films of PVP decreased the diffusion limiting oxygen reduction current. The effect of pH of the electrolyte solution on the activity of such PVP-modified electrodes for oxygen reduction has also been investigated.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01077582
