Solubility, theoretical capacity, equilibrium potential and electrochemical kinetic parameters of different TEMPO derivatives in KCl aqueous solutions at room temperature.
| Sample | Solubility in pure water (M) | Solubility in 0.5 M KCl (M) | C Theo a (Ah L−1) | E 0 b (V) | D c (cm2 s−1) | k 0 d (cm s−1) |
|---|---|---|---|---|---|---|
| 4HT | 2.11 | 1.25 | 33.5 | 0.812 | 3.14 × 10−6 | 4.45 × 10−3 |
| 4OT | 1.22 | 0.79 | 21.2 | 0.910 | 4.61 × 10−6 | 1.05 × 10−2 |
| 4AT | 5.79 | 4.80 | 128.6 | 0.895 | 3.77 × 10−6 | 4.01 × 10−3 |
| 4CyT | 2.6 × 10−2 | NA | NA | 0.881 | 6.23 × 10−6 | 4.29 × 10−3 |
| 4CaT | 2.1 × 10−2 | NA | NA | 0.776 | 2.64 × 10−6 | 2.25 × 10−3 |
a
Theoretical capacity (CTheo) were calculated based solubility of materials in 0.5 M KCl solution.
b
Equilibrium potential (E0) was obtained from CV measurements in 0.5 M KCl solution.
c
Diffusion coefficient (D) that is an average value of DO and DR.
d
Electron transfer constant (k0) was measured from RDE measurements in 0.5 M KCl solution.