Explicit finite-difference digital simulation of the effects of rate-controlled product adsorption or deposition in double-potential-step chronocoulome

EChem++ – An object-oriented problem solving environment for electrochemistry. Part 5. A differential-algebraic approach to the error control of adaptive algorithms

“…Thus, the reduction peak is more pronounced. Similar effects can be found in ''the handbook of voltammograms'' [24], which describes the cyclic voltammetric response of an adsorbed monolayer (system (22), plus adsorption/desorption of product B ads ) for planar (1 D model, as used here) and microdisk diffusion conditions (2D model). The concept presented here may be used for the modeling and simulation of even more complex systems involving adsorbed molecules, as will be shown in the following.…”

“…7 were obtained with the same error tolerances as in the case of system (22). Although no direct comparison to analytical calculation Fig.…”

“…Within the electrochemical literature it has been often assumed that adsorption proceeds sufficiently fast that equilibrium forms of the adsorption isotherms may be employed [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]. Dynamic (rate controlled) adsorption processes, however, were considered only either conceptionally [18][19][20] 1 or for specific mechanisms [22][23][24]. A model that treats two dynamic adsorption steps coupled to a heterogeneous electron transfer of the adsorbed species has been recently described by Chevallier et al [24].…”

“…Cyclic voltammetry simulations of the adsorption redox system(22); analytical (s, reversible) and simulated voltammograms for (a) one-and (b) two-electron-transfer reactions with rate constant of AET k s = 1(Á Á Á), 10(-AE-), 10 2 (--) and 10 3 s À1 (-); (c) time step sizes s and (d) surface concentrations of A ads (-) and B ads (--) for n = 1 and k s = 10 3 s À1 ; parameters of simulations: T = 293.15 K, c 0 A ¼ 10 À4 mol l À1 , D A = 10 À5 cm 2 s À1 , c 0 A ads ¼ c s ¼ 10 À10 , c 0 B ads ¼ 0 mol cm À2 , K = 10 5 cm 3 mol À1 , k ads = 10 2 cm 3 mol À1 s À1 (thus, k des = 10 À3 s À1 ), E 0 = 0.25 V and a = 0.5; cyclic voltammetry excitation: E init = 0.0 V, E k = 0.5 V and v = 1 V s À1 .…”

Adsorption of Viologen-Based Polyelectrolytes on Carboxylate-Terminated Self-Assembled Monolayers

“…The interaction of dodecyl sulfate anions with viologens and, particularly, viologen cation radicals is well-known. − We reasoned that the viologen subunits in the adsorbed polyelectrolyte might also interact strongly with dodecyl sulfate anions and the resulting changes in their voltammetric behavior may be useful to detect and perhaps quantitate the surfactant anions. In order to investigate this possibility, we exposed Au/SC 7 COOH electrodes to 60 μM VC 11 to reach the saturation level for polyelectrolyte adsorption and the voltammetric response was recorded (Figure a).…”