Kinetics of electrocrystallization of PbO2 on glassy carbon electrodes: influence of electrode rotation

Abstract

Electrodeposition of PbO2 on glassy carbon electrodes was studied in stationary conditions and on the rotating disk electrode using chronoamperometric technique. The kinetics of electrodeposition was significantly retarded by the hydrodynamic mass transport flow. This observation is in agreement with the mechanism involving formation of soluble Pb(III) or Pb(IV) species, which may, subsequently, form PbO2. The kinetics of the nucleation and crystal growth was determined by the analysis of the initial part of the transients and of the whole curves. This process proceeds through the 3 dimensional progressive nucleation and crystal growth mechanism with an induction time. The growth rate constant is strongly affected by convection while the nucleation process and the induction time are much less influenced.