Generally with oxygen, the OCV of a cathode electrode has some value, but with increasing or decreasing the dissolved oxygen (DO), will it affect the point of reduction peak in cyclic voltammetry?
The peak of oxygen reduction in a cyclic voltammogram is a typical case of a voltammetric peak associated to an irreversible process. In this case, the peak current should depend (linearly) on the concentration, but the peak potential not. The peak potential will shift, however, with the scan rate, and a plot of the peak potential vs. the logarithm of the scan rate would yield the Tafel slope.
Its true that the reduction potential will not affects with concentration of dissolved oxygen. Moreover, for ORR you need to perform RDE or RRDE exp with oxygen. The reduction potential will change with scan rate and rotation speed.
Actually, with an RDE you will not have a peak, but a diffusion-limited plateau. As far as you do not rotate so fast as to provoke turbulence, the faster you rotate the more negative the potential at which you reach the diffusion-limited plateau.
Thank you very much Angel Cuesta, Avijit Ghosh and Yusuke Okawa for you valuable suggestions.
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