Dear Dhrubajyoti Bhattacharjya,

in order to address your question, one possibility is as follows (I am assuming a standard half-cell electrochemical setup):

1) you determine carefully your potential scale with primary standards (e.g., the reversible hydrogen electrode);

2) you collect cyclic voltammogramms of your electrode bubbling oxygen in the liquid electrolyte;

3) you remove oxygen by bubbling Ar or N2 in the liquid electrolyte, and collect another voltammogramm on the very same electrode, in the same conditions;

4) you subtract the trace collected in N2 from the trace collected in O2. By doing so, you remove most capacitive currents, leaving only the faradic ORR current;

5) you correct the faradic currents from other interferences (e.g., mass-transport contributions, if you are working with a rotating-disk electrode);

6) you carry out Tafel analysis;

7) last but not least, you compare your results with the literature.

Hope it helps!

Best Regards

Enrico

see the following link it may helpfull

https://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&ved=0CDwQFjAB&url=http%3A%2F%2Fwww.springer.com%2Fcda%2Fcontent%2Fdocument%2Fcda_downloaddocument%2F9781848009356-c1.pdf%3FSGWID%3D0-0-45-602204-p173838515&ei=sEVRUpuCNMPhrAeT5oGgBw&usg=AFQjCNHDIpL2Zwa5s50lXyYVMvmLzhDFvA&sig2=72pfPIAnQPkt6sv8X17GZg&bvm=bv.53537100,d.bmk

Thanks Enrico for your answer for your answer, But I am finding to do the tafel analysis actually, Should I extract the kinetic current by using K-L plot or should I do the tafel analysis on the RDE LSV itself ?.

Dear Dhrubajyoti Bhattacharjya,

you can do the Tafel analysis on the RDE LSV itself. However:

1) you should do the LSV fast enough to prevent the contamination of the surface of the electrocatalyst, and slow enough to minimize capacitive currents. A scan speed between 5 and 20 mV/sec is generally OK;

2) you should be careful to remove all spurious contributions from your faradic currents (e.g., capacitive currents and mass-transport currents)

K-L plot is generally used to study ORR selectivity (if you don't have a RRDE); it is not mandatory to study ORR mechanism at low ORR overpotentials.

Hope it helps!

Best Regards

Enrico