Dramatic Effects of Ionic Liquid on Platinum Electrode Surface and Electron-Transfer Rates ofmeso-Tetraphenylporphyrins

2006 ◽  
Vol 18 (12) ◽  
pp. 1227-1229 ◽  
Author(s):  
Afsaneh Safavi ◽  
Zarangiz Movahedi ◽  
Daryush Mohajer ◽  
Norouz Maleki
Keyword(s):  
Electron Transfer ◽  
Ionic Liquid ◽  
Electrode Surface ◽  
Platinum Electrode ◽  
Transfer Rates

Comparison of Gold and Platinum Electrode Responses in Activated Sludge

1993 ◽  
Vol 28 (11-12) ◽  
pp. 473-480
Author(s):  
A. Heduit ◽  
B. Martin ◽  
I. Duchamp ◽  
D. R. Thevenot
Keyword(s):  
Electron Transfer ◽  
Activated Sludge ◽  
Gold Electrode ◽  
Platinum Electrode ◽  
Electrochemical Determination ◽  
Exchange Current ◽  
Experimental Conditions ◽  
Equilibrium Exchange ◽  
Prolonged Contact ◽  
Current Densities

Gold and platinum were compared to ascertain how they expressed a stabilized potential in activated sludge. The comparison was based on electrochemical determination of the electron transfer rate (i.e. equilibrium exchange current density) and recording of potentials against time. When both metals are treated in the same way, platinum gives equilibrium exchange current densities approx. 10 times higher than gold, both in aerated activated sludge and in treated water. For platinum, the equilibrium exchange current densities range from 0.1 to 0.25 µA/cm2 immediately after polishing and decrease during prolonged contact with activated sludge subjected to alternating aeration/anoxia sequences. The lower kinetics of electron transfer on gold go together with significant differences in response:- In an aerobic medium a gold electrode potential is lower than that of a platinum electrode. In a strongly anaerobic medium, the reverse is true. Consequently, the amplitude of the potential variation between aerobic and anaerobic media is smaller for gold than for platinum. Under our experimental conditions this amplitude was approx 350 mV for gold and 850 mV for platinum.- The slopes of the linear relationships between potential and pH or potential and the logarithm of the dissolved oxygen concentration are two or three times greater for platinum than for gold. Although the values obtained with platinum electrodes cannot represent a veritable equilibrium state, the platinum electrode zero-current potential would seem to be far more sensitive to variations in the medium than that of the gold electrode; it is, therefore, more suitable for use in activated sludge.

The Effect of p-Toluidine on the Two-Step Electroreduction of Zn(II) in Water-Methanol and Water-Dimethylformamide

1999 ◽  
Vol 64 (4) ◽  
pp. 585-594 ◽  
Author(s):  
Barbara Marczewska
Keyword(s):  
Electron Transfer ◽  
Binary Mixtures ◽  
Rate Constant ◽  
Rate Constants ◽  
Electrode Surface ◽  
Mercury Electrode ◽  
Forward Rate ◽  
Solvent Molecules ◽  
Activated Complex

The acceleration effect of p-toluidine on the electroreduction of Zn(II) on the mercury electrode surface in binary mixtures water-methanol and water-dimethylformamide is discussed. The obtained apparent and true forward rate constants of Zn(II) reduction indicate that the rate constant of the first electron transfer increases in the presence of p-toluidine. The acceleration effect may probably be accounted for by the concept of the formation on the mercury electrode an activated complex, presumably composed of p-toluidine and solvent molecules.

Quantification of Electron Transfer Rates to a Solid Phase Electron Acceptor through the Stages of Biofilm Formation from Single Cells to Multicellular Communities

2010 ◽  
Vol 44 (7) ◽  
pp. 2721-2727 ◽  
Author(s):  
Jeffrey S. McLean ◽  
Greg Wanger ◽  
Yuri A. Gorby ◽  
Martin Wainstein ◽  
Jeff McQuaid ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Electron Acceptor ◽  
Biofilm Formation ◽  
Solid Phase ◽  
Single Cells ◽  
Transfer Rates

Four Aspects of the Distance Dependence of Electron-Transfer Rates

1982 ◽  
pp. 213-233 ◽  
Author(s):  
EPHRAIM BUHKS ◽  
RALPH G. WILKINS ◽  
STEPHAN S. ISIED ◽  
JOHN F. ENDICOTT
Keyword(s):  
Electron Transfer ◽  
Transfer Rates ◽  
Distance Dependence
Sign in / Sign up

Export Citation Format

Share Document