I run a CV for an organic compound and oxidation peaks were appeared in the negative current range.
Dear Mr. Simbu,
As John Willey says, negative currents usually correspond to reduction peaks in the usual accepted convention for cathodic reactions (negative currents) and anodic reactions (positive currents). In some cases, US accepted convention for current sign is the opposite, that means negative currents correspond to anodic reactions (oxidation) and positive ones to cathodic ones (reduction). Just check if your equipment is using the US convention. Alternatively, a way to check such issue is using a known redox compound (for example ferri/ferro cyanide 1 mM in KNO3 0.1M) and see what is happening. That means, when doing cyclic voltammetry you should observe the reduction of ferri/ferro scanning the potential to more negative values and the oxidation of ferro/ferri in the reverse scan (going to more positive values). If the current you observe in the reduction process is negative, your equipment is working in the usual way, if not, then it is working in the US convention of current signs.
Otherwise, have you think about electrocatalytic reactions to take place in your system?.
I hope this comment can help you. Good luck.
Cheers
This is instrumental. Change a polarity of output current in your instrument.
Dear Mr. Simbu,
As John Willey says, negative currents usually correspond to reduction peaks in the usual accepted convention for cathodic reactions (negative currents) and anodic reactions (positive currents). In some cases, US accepted convention for current sign is the opposite, that means negative currents correspond to anodic reactions (oxidation) and positive ones to cathodic ones (reduction). Just check if your equipment is using the US convention. Alternatively, a way to check such issue is using a known redox compound (for example ferri/ferro cyanide 1 mM in KNO3 0.1M) and see what is happening. That means, when doing cyclic voltammetry you should observe the reduction of ferri/ferro scanning the potential to more negative values and the oxidation of ferro/ferri in the reverse scan (going to more positive values). If the current you observe in the reduction process is negative, your equipment is working in the usual way, if not, then it is working in the US convention of current signs.
Otherwise, have you think about electrocatalytic reactions to take place in your system?.
I hope this comment can help you. Good luck.
Cheers
the negative sign represent reduction reaction at cathode. ie electron transfer takesplace in the reverse direction. we should note the magnitude.
hello all
when you polarize the current that is flowing is the net current
from the zero current crossing potential if the polarization is in the positive ( note i am using the word positive) the current flowing is NET anodic current
SO ALSO in the negative direction
if you do CV the inverted anodic or cathodic peaks are due the net current flow ing
may be anodic or cathodic
see my papers on inverted anodic peaks
can i took cv in range of 0.2 to 0.4 rather than starting from zero?
The best would be to start from the solution rest potential. Almost all instruments can measure it.
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