usually increasing scan rate during CV the voltagram of CNF also increases in size but when I am increasing the scan rate the size of CNF voltagram is shrinking. what should be done? I am using a three electrode setup and Pt electrode as CE
What is meaning of size here?
If I am not wrong, I guess you are talking about non faradaic current. It might be due to detachment of CNF from the electrode surface. If you repeat measurement of CV with same scan rate and if you observe decrease in capacitance or non faradaic current that will confirm detachment.
Or other possibility might be blocking of CNF surface due to some chemical or electrochemical reaction. It is important to mention about electrolyte and possible reaction which you are expecting. With the given information it is difficult to conclude it. So if possible, can you provide some more details of your experimental set up and reaction?
Thanks for your interest.
I have attached my data which will elaborate what i mean by size. basically by increasing the scan rate my voltagram is shriking. It should do the opposite, thats what all the literature shows.
I am using NaHCO3 as electrolyte. further details and results are attached in the ppt file. I am using CNF paper as WE
Are you carrying experiments in nitrogen or in air/oxygen? Second, why you are taking NaHCO3 as supporting electrolyte? Change the electrolyte where no evolution of gas is occuring. It may be possible that by increasing scan rate there is some disintegration of electrolyte which may lead to poisoning of your CNF electrode resulting in decrease in your cv shape. Moreover, the CV which I have observed in your ppt. is not give any relevant data in the present potential window.
1. i am performing these experiments under ambient conditions just air.
2. i want to use strong bases but the frit of my RE dissolves (malfunction) for electrolyte with ph 10 n higher.
3. how the results of CV changes if someone uses strong ACID (HCL) instead of strong base? or there is no difference in CV
Why you are using SCE electrode as reference electrode? Why not Ag/Ag+ reference electrode. And why NaHCO3 electrolyte and why not KCl medium. Even this reference electrode can be used in acidic medium also.
we only have SCE refference electrode. order and delivery time is too long to wait for. Problem is with frit of refference electrode. it breaks (dissolves) in basic solution.
OK. I tell you a simple method of preparing Ag/Ag+ reference electrode. Take a silver wire (0.5 to 1 mm thick) and dip in in 1.0 N HCl. A layer of AgCL will be formed. Rinse it and dry it, This then be simply used as a RE.
Record Differential pulse voltametry instead of CV.
HAve you measured the resistivity of your CNF paper?
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