Cyclic voltammetric studies of nickel hydroxide and cobalt hydroxide thin films in alkali and alkaline earth metal hydroxides |
| |
| Authors: | P. Vishnu Kamath M. F. Ahmed |
| |
| Affiliation: | (1) Department of Chemistry, Central College, Bangalore University, 560001 Bangalore, India |
| |
| Abstract: | Cyclic voltammetric studies of thin films of electrosynthesized (ES)-Ni(OH)2 and Co(OH)2 in different alkaline electrolytes suggest that the mechanism of oxidation is different from the mechanism of reduction. While the metal ion (alkali or alkaline earth metal) intercalation-deintercalation from the electrolyte into the film provides the driving force, the reduction reaction takes place heterogeneously independent of the electrolyte concentration, whereas oxidation takes place homogeneously across a nebulously defined electrode-electrolyte interphase. ES-Ni(OH)2 permits facile intercalationdeintercalation of alkali metal ions Li+, Na+ and K+, irrespective of their ionic size, while the reactions of ES-Co(OH)2 are sensitive to ionic size, requiring larger potentials in KOH compared to LiOH. In the alkaline earth metal hydroxides, both Ni(OH)2 and Co(OH)2 films show greater reversible characteristics in the order Ba(OH)2 > Sr(OH)2 > Ca(OH)2. This may be trivially related to the order of the solubilities of the three hydroxides. |
| |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ |
|
