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Oliver Rodriguez edited this page Mar 2, 2022 · 14 revisions

Macro

Calculates typical equations assuming planar diffusion.

Macro(n=1, A=1, CR=1e-6, DR=1e-5, T=298)

Parameters:

  • n : float, number of electrons
  • A : float, [cm2], electrode area
  • CR : float, [mol/cm3], bulk concentration of R
  • DR : float, [cm2/s], bulk concentration of O
  • T : float, [K], temperature

Example:

import softpotato as sp
macro = sp.calculate.Macro(A=0.01, CR=5e-6)

macro.Cottrell(t)

For a full example, visit Cottrell.ipynb

Parameters:

  • t : numpy_array, [s], time to calculate the current

Returns:

  • out: numpy_array, [A], cottrellian current calculated over t

Example:

import numpy as np
t = np.linspace(0.01,1)
i_cottrell = macro.Cottrell(t)

macro.RandlesSevcik(sr)

For a full example visit RandlesSevcik.ipynb

Parameters:

  • sr : numpy_array, [V/s], scan rates

Returns:

  • out: numpy_array, [A], current calculated at each scan rate

Example:

i_RS = macro.RandlesSevcik(sr)

MicroDisc

Calculates typical equations assuming hemispherical diffusion.

Microdisc(a=5e-4, n=1, DO=1e-5, DR=1e-5, CR=1e-6, E0=0, k0=1e8, alpha=0.5, T=298, noise=0)

Parameters:

  • a : float, [cm], electrode radius
  • n : float, number of electrons
  • DO : float, [cm2/s], diffusion coefficient of O
  • DR : float, [cm2/s], diffusion coefficient of R
  • CR : float, [mol/cm3], bulk concentration of R
  • E0 : float, [V], formal potential
  • k0 : float, [cm/s], standard rate constant
  • alpha : float, transfer coefficient
  • T : float, [K], temperature
  • noise : float, [A], magnitude of random normal noise

Returns:

  • iLim : instance, float, [A], limiting current

Example:

import softpotato as sp
ume = sp.calculate.MicroDisc
iLim = ume.iLim

ume.LSV(E)

Calculates the current using the equation reported by Oldham and Zoski:

For a full example visit microdisc_LSV.ipynb

[1] Keith B.Oldham and Cynthia G.Zoski. Comparison of voltammetric steady states at hemispherical and disc microelectrodes, Journal of Electroanalytical Chemistry and Interfacial Electrochemistry, Volume 256, Issue 1, 25 November 1988, Pages 11-19. DOI: https://doi.org/10.1016/0022-0728(88)85002-2.

Parameters:

  • E : numpy_array, [V], potential array

Returns:

  • out : numpy_array, [A], current calculated according to [1]

Example:

tech_lsv = sp.technique.Sweep()
i_lsv = ume.LSV(tech_lsv.E)

ume.CA(t, Es=1)

Calculates the current using the equation reported by Perry, Al Shandoudi and Denuault:

For a full example, visit microdisc_CA.ipynb

[2] Samuel C. Perry, Laila M. Al Shandoudi, and Guy Denuault. Sampled-Current Voltammetry at Microdisk Electrodes: Kinetic Information from Pseudo Steady State Voltammograms, Analytical Chemistry, 2014, 86 (19), 9917-9923. DOI: https://doi.org/10.1021/ac502645e.

Parameters:

  • t : numpy_array, [s], time array
  • Es : float, [V], potential step

Returns:

  • out : numpy_array, [A], current calculated according to [2]

Example:

tech_ca = sp.technique.Step()
i_ca = ume.CA(tech_ca.t, Es=1)

For more info, visit Soft Potato.

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