Nucleation and Growth Study of Nano-PbO₂ on Ti in Different Additives for Electrocatalytic Oxidation Process

Electrocrystallization of PbO₂ on Ti electrode was studied in different bath solutions using cyclic voltammetry (CV), chronoamperometry (CA), and scanning electron microscopy. The cyclic voltammetry studies revealed that the addition of methanol postponed the oxygen evolution region and made over potential nucleation of PbO₂ on Ti. Oxidation of PbO₂ is preferred in second cycle (a peak) in other studied bath solutions, except the Nafion and aniline containing solution. In the presence of the pyrrole, the PbO₂ formed at under deposition potential with less in numbers. Nafion and aniline inclusion turn the process in to progressive nucleation and growth without inhibition. On the other hand, other solutions studied are revealed the instantaneous nucleation and growth or inhibition at high potentials. Surface morphology explained that ≅300 nm sizes PbO₂ particles with vertical nucleation and growth phenomena evidenced the Nafion and aniline are the important dopants. The results indicated that large current density or high potential polarization can be obtained in presence of methanol, Nafion, and aniline, which is one of the most important and necessary factors for forming high surface area PbO₂ with strong adherence towards mediated electro-oxidation process.