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Nafion-Coated Electrodes and Electrogenerated Chemiluminescence of Surface-Attached Ru ( bpy ) 32 +
| Content Provider | Semantic Scholar |
|---|---|
| Author | Olah, George Karthik, Gowri Hakash, Surya Ananaghi, Massoud |
| Copyright Year | 2001 |
| Abstract | minescence at the polymer layer is produced upon oxidation of the 2+ Ru species in the presence of oxalate ion. Electroactive groups can be bound uite readily to an electrode surface in the form of a polymer layer?+ where either the polymer itself is electroactive [e.g., poly(viny1ferrocene) JZa or the electroactive molecules are later attached into the polymer [e.g., Ru(NH3);+ on polyacrylic acidIs4b In the latter example, Oyama and Anson demonstrated that ions from solution could be bound to the polymer by exploiting its ion-exchange properties (electrostatic binding).“ Nafion (l), an ion-exchange polymer which is very resistant to chemical attack, even by strong oxidants a t elevated temperatures, has found increasing use as a membrane material. We have found that a pyrolytic graphite (PG) electrode can be coated with this material. In a typical experiment, a layer of -1.4 mg of Nafion polymer/cm2 of electrode surface was prepared by dip coating. The electrode was dipped into a solution of -2% Nafion (equiv wt -970) in ethanol, then taken out and dried in the air, leaving the polymer film on the surface. The film thickness can be estimated by using the density of dry commercial Nafion membranes (-2 g cm-,) as -7 pm (dry). The polymer-coated electrode was then immersed for 10-15 min in a solution of 5 mM Ru(bpy),C12 in 0.1 M H2SO4, rinsed thoroughly with distilled water, and transferred to the electrochemical cell. Electrodes prepared in this manner acquire a deep orange color, demonstrating the large amount of Ru(bpy)?+ incorporated into the polymer. Such an electrode, denoted as PG/Nafion, R ~ ( b p y ) , ~ + , shows the cyclic voltammetric behavior characteristic of the Ru( b p ~ ) , ) + / ~ + couple when immersed in a solution containing only supporting electrolyte (Figure la). However, the observed oxidation and reduction peaks are broad and separated by 170 mV at this scan rate, markedly deviating from the expected behavior |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://bard.cm.utexas.edu/resources/Bard-Reprint/241.pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
