TY - JOUR
T1 - Electrode Material Dependence of the Electron Transfer Kinetics Associated with the [SVW11O40]3-/4- (VV/IV) and [SVW11O40]4-/5- (WVI/V) Processes in Dimethylformamide
AU - Li, Jiezhen
AU - Guo, SiXuan
AU - Bentley, Cameron L
AU - Bano, Kiran
AU - Bond, Alan M
AU - Zhang, Jie
AU - Ueda, Tadaharu
PY - 2016/5/20
Y1 - 2016/5/20
N2 - In this study, large amplitude Fourier transformed alternating current (FTAC) voltammetry has been used to determine the heterogeneous electron-transfer kinetics (k° and α values) associated with the vanadium [SVW11O40]3-/4- (VV/IV, E° = 0.050 V vs. Fc/Fc+, where Fc = ferrocene) and tungsten [SVW11O40]4-/5- (WVI/V, E° = -1.530 V vs. Fc/Fc+) processes in dimethylformamide containing tetrabutylammonium hexafluorophosphate as the supporting electrolyte. At glassy carbon (GC), platinum (Pt), gold (Au) and boron-doped diamond (BDD), the VV/IV process is kinetically more facile than the WVI/V one. Excellent simulation-experiment fits were achieved for the VV/IV process at all electrode materials, and at a supporting electrolyte concentration of 0.1 M, the k° value associated with this process increases in the order BDD <Pt ≈ Au <GC. By contrast, at all electrode materials except GC, generally poor simulation-experiment fits were achieved for the WVI/V process, preventing the data from being analysed quantitatively by FTAC voltammetry. Changing the concentration of supporting electrolyte from 0.1 to 0.5 M has a significant influence on the kinetics, with the k° value increasing at GC and decreasing at Pt, Au and BDD. Overall, the findings indicate that differences in density of states do not fully explain the electrode material dependence of the k° values and that other factors such as surface functional groups (on GC) and the double layer effect need to be taken into consideration.
AB - In this study, large amplitude Fourier transformed alternating current (FTAC) voltammetry has been used to determine the heterogeneous electron-transfer kinetics (k° and α values) associated with the vanadium [SVW11O40]3-/4- (VV/IV, E° = 0.050 V vs. Fc/Fc+, where Fc = ferrocene) and tungsten [SVW11O40]4-/5- (WVI/V, E° = -1.530 V vs. Fc/Fc+) processes in dimethylformamide containing tetrabutylammonium hexafluorophosphate as the supporting electrolyte. At glassy carbon (GC), platinum (Pt), gold (Au) and boron-doped diamond (BDD), the VV/IV process is kinetically more facile than the WVI/V one. Excellent simulation-experiment fits were achieved for the VV/IV process at all electrode materials, and at a supporting electrolyte concentration of 0.1 M, the k° value associated with this process increases in the order BDD <Pt ≈ Au <GC. By contrast, at all electrode materials except GC, generally poor simulation-experiment fits were achieved for the WVI/V process, preventing the data from being analysed quantitatively by FTAC voltammetry. Changing the concentration of supporting electrolyte from 0.1 to 0.5 M has a significant influence on the kinetics, with the k° value increasing at GC and decreasing at Pt, Au and BDD. Overall, the findings indicate that differences in density of states do not fully explain the electrode material dependence of the k° values and that other factors such as surface functional groups (on GC) and the double layer effect need to be taken into consideration.
KW - Electrode material dependence
KW - Electron transfer kinetics
KW - Fourier transformed alternating current voltammetry
KW - Polyoxometalates
UR - http://www.scopus.com/inward/record.url?scp=84962920837&partnerID=8YFLogxK
UR - http://ac.els-cdn.com.ezproxy.lib.monash.edu.au/S001346861630648X/1-s2.0-S001346861630648X-main.pdf?_tid=ac6f5188-7881-11e6-922b-00000aacb35f&acdnat=1473641082_7c18f1b49a060b3ca3ec62e42e838d83
U2 - 10.1016/j.electacta.2016.03.107
DO - 10.1016/j.electacta.2016.03.107
M3 - Article
AN - SCOPUS:84962920837
VL - 201
SP - 45
EP - 56
JO - Electrochimica Acta
JF - Electrochimica Acta
SN - 0013-4686
ER -