Effects of solution viscosity on heterogeneous electron transfer across a liquid/liquid interface |
| |
| Authors: | Yamin Bai Meiqin Zhang Zhengyu Yang |
| |
| Affiliation: | a Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100101, China
b State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China |
| |
| Abstract: | Scanning electrochemical microscopy (SECM) is employed to investigate the effect of solution viscosity on the rate constants of electron transfer (ET) reaction between potassium ferricyanide in water and 7,7,8,8-tetracyanoquinodimethane (TCNQ) in 1,2-dichloroethane. Either tetrabutylammonium (TBA+) or ClO4− is chosen as the common ion in both phases to control the interfacial potential drop. The rate constant of heterogeneous ET reaction between TCNQ and ferrocyanide produced in-situ, k12, is evaluated by SECM and is inversely proportional to the viscosity of the aqueous solution and directly proportional to the diffusion coefficient of K4Fe(CN)6 in water when the concentration of TCNQ in the DCE phase is in excess. The k12 dependence on viscosity is explained in terms of the longitudinal relaxation time of the solution. The rate constant of the heterogeneous ET reaction between TCNQ− and ferricyanide, k21, is also obtained by SECM and these results cannot be explained by the same manner. |
| |
| Keywords: | Solution viscosity Electron transfer rate constant Scanning electrochemical microscopy Water/1,2-dichloroethane interface Longitudinal relaxation time |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
