Spectroelectrochemistry with cylindrical carbon-fiber microelectrodes

✍ Scribed by Yuanwu Xie; Guangli Che; Shaojun Dong

• Publisher: Elsevier Science
• Year: 1991
• Tongue: English
• Weight: 490 KB
• Volume: 36
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/0013-4686(91)85202-i

✦ Synopsis

At&act-Transmittance

spectroelectrochemistry can be performed using a group of cylindrical microelectrodes. A dependence of absorbance on electrolytic charge during the potential step was derived. The rate constant of catalytic reaction of the ferrocyanidcascorbic acid system was determined using single potential step-open circuit relaxation chronoabsorptometry. This is the tirst report that the reaction can still be considered as a pseudo-first-order reaction when the concentration of ascorbic acid is close to and even slightly lower than the concentration of ferrocyanide. The determined rate constant is in agreement with the reported value. The reason is that the diffusion of ascorbic acid toward electrode surface is contractive and the diffusion of the electrogenerated ferricyanide from the electrode surface to the bulk of solution is expansive.