In fl uence of electrode material and roughness on iron electrodeposits dispersion by ultrasoni fi cation

This study relates the sonoelectrochemical production of metallic particles and nanoparticles. The emphasis is on the influence of electrode material and roughness on the morphology of iron electrodeposits and their dispersion from the electrode by ultrasonification. Ultrasonification is either applied during cyclic voltammetries with solution stirring or after galvanostatic iron electrodeposition; no dispersion was observed when using a gold electrode, whereas dispersion was always observed when using vitreous carbon (VC) substrates. Scanning Electron Microscopy (SEM) imaging of the electrodeposits shows higher iron coverage on gold than on VC electrodes. Iron spreads more on gold than on VC. The values of both the interfacial energy of the iron/electrode interface and the work of adhesion of iron on the electrode are in agreement with the previous observations. Dispersion kinetics on VC were found to be dependent on the electrode surface roughness. Results suggest that dispersion follows a first order kinetics, which is coherent with the constant action of cavitation bubbles in the vicinity of the electrode surface. Enhancement of mass-transfer by ultrasound has also been observed.