The fact that in both branches (anodic and cathodic) all the plots tend to the same current value may indicate that this value corresponds to the limit of the equipment, as, otherwise, the current would keep increasing. That is, in my opinion, the feeling of the reviewer.

You may check the specifications of your potentiostat to find the maximum current.

Good luck.

Hi Ruby, can you identify the current range setting you used on the autolab?

Dear Dr. Richard Barker,

The current range was fixed as follows:

Highest current range: 1mA and the lowest current range: 100nA.

Hi Ruby, typically with most potentiostats you can only measure up to 4-5 times the max current range setting. Your currents are approaching 10mA so it is very likely hitting that max current. You will need to repeat the test and either increase the max current setting to 10mA or reduce the area of the test coupon by an order of magnitude.

Dear Dr. J.C.S. Fernandes ,

Thanks for your reply.

The current range saved in the procedure is:

Highest current range: 1mA and the lowest current range: 100nA.

What can I do now to deal with the problem?

Dear Ruby

I agree with Richard Barker. If you are defining the higher current range, you should increase it. If it is defined by the potentiostat (or if the specifications indicate that this is the maximum current) then you may decrease the surface area of your specimen.

Dear J.C.S. Fernandes, Thank you very much for your assistance. I'll make the necessary changes in my previously saved procedure.