Enzymatic oxygen reduction under quiescent conditions — the importance of convection

Abstract

Over the last decade the current densities reported from biocathodes for oxygen reduction have increased dramatically. However, many reports in the literature of measurements performed under quiescent conditions appear to show current densities above the mass transport limit. We measure the native convection of electrolyte in an electrochemical cell and show that by including this movement in computer simulations experimental data can be reproduced. Thus we clearly show that convection plays an important role when interpreting results from slow scan cyclic voltammetry and that care must be taken not to conflate electrode performance with hydrodynamic effects.