Why is the reduction of Cu(I) to Cu(0) (electrodeposition) not complemented by a peak in current in cyclic voltammetry? Why is this peak not observable, but the oxidation of Cu(0) to Cu(I) is (stripping peak)?
The system in question is an aqueous solution of 10mM Cu(II) Chloride with 100mM KCl electrolyte. Scans are taken at wide window, between 1.5V and -1.5V, and also between 0.4V and -0.4V to zoom in on the copper redox couple peaks.
Dear
I think that there is a problem in the scan rate
1- the reduction process have enough time to interfere with another parallel reaction
2- the diffusion of Cu ions is much faster than the electrochemical reaction
Please see this link for more clarification
https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Book%3A_Analytical_Chemistry_2.0_(Harvey)/11_Electrochemical_Methods/11.4%3A_Voltammetric_Methods
I hope that this can be beneficial
Regards,
dear Anonymous researcher;
I think the problem in the reference electrode and the scan range.
better to use (SSE) silver/silver chloride Ag/AgCl vs Pt cathode to avoid effects of Chloride contamination and scan for voltage between 2.5V and -2.5V, with scan rate 0.015-0.02 v/s.as in the attached figure.
Apply a low(er) V-window scan, in between 1.2V (or 0.5V) and -0.5V, for your (Halogen Salts, KCl) electrolyte in water; apply a low(er) scan (V-)rate 10mV/s, or even lower (1mV/s).
Also, add, if possible, a 3rd Electrode, as a RE; it is recommended to add the SSE (RE: Silver/Silver Chloride, Ag//AgCl, as a 3rd -) Electrode.
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