2. Apparent lower FEs at low rotation rates can be easily caused by experimental conditions. These effects need be explicitly eliminated in order to observe possible influences of mass transport or species' retention times in RRDE experiments at different rotation rates.

1. FE can be accurately determined even at low rotation rates, but this requires certain precautions: experimentally determining the collection efficiency under the relevant conditions, observing the total charge associated with the ring current due to current peak delay and widening, or both

I am an electrochemist with 10+ years experience in academic research:

scholar.google.com/citations?us...