Undistorted Cyclic Voltammograms at Scan Rates up to 2.5 MVs~(-1) through Positive Feedback Compensation of Ohmic Drop

Introduction Though being the simplest voltammetric technique, cyclic voltammetry provides lots of electrochemical information especially in the study of the thermody-namic and kinetic processes and the detection of elec-trogenerated transient intermediates.1 Clearly, the more rapid the scan rate is employed, the faster the reactions can be studied. Indeed, a timescale RT/Fν～25 ns of the Faradaic response will be reached corresponding to a scan rateνof 1 MVs-1, which means that the method…

Undistorted Cyclic Voltammograms at Scan Rates up to 2.5 MVs~(-1) through Positive Feedback Compensation of Ohmic Drop

A circuit based on the current feedback operational amplifier was constructed to accomplish on-line ohmic drop compensation in ultrafast cyclic voltammetry. Firstly, its characteristics were confirmed experimentally on dummy cells. Then the reduction of anthracene in acetonitrile, a classical test example with very fast electron-transfer kinet-ics, was examined to prove them too. The results showed that this circuit could afford excellent ohmic drop com-pensation so that the undistorted voltammograms up to 2.2 MVs-1 scan rate can be recorded, and 2.5 MVs-1 if 5% error is tolerated.