The Electrodeposition Of Tin On Self-assembled Structure Of Phthalic Acid Assisted By Surfactants

The effect of intermolecular interaction of Phthalic acid (PA) and surfactants on electrodeposition was studied and the electrodeposition of tin was used as a model system. The idea of the present study is to form an additive molecule networkon a cathode surface governed by the intermolecular interactionto block or to limit the access of metal ions during the electrodeposition. In an attempt to seek a possibility to tune the incorporation of theadsorbed additive and the inhibition to the electroreduction reactionon the electrode, we choose aromatic carboxylic acids as the controllingmolecular units. The adsorption of aromatic carboxylic acidsat electrode-electrolyte interfaces has drawn a great deal of interest,because the adjacent molecules may be linked with hydrogen bondinginteractions, π-stacking, and van der Waals forces and results inself-assembled molecular networks.The CV curve of the electrolyte in the presence of a combination of PA and Triton x100 indicates that a relatively compact adlayer forms on the electrode surface and the electrodeposition of tin is inhibitedvery well. It is expected that the aromatic character of the hydrophobic moiety of both Triton x100 and PA enhance the binding interactionand the blocking effect is governed by the intermolecular interaction between PA and Triton x100. Scanning electron microscopic (SEM)image shows that a smooth, regular and compact deposit was obtained from the electrolyte with both PA and Triton x100. A relativelylow carbon content of the deposit indicates that the incorporation of the additive in a deposit is strongly controlled in the presenceof both PA and Triton x100. The possible explanation for the reduced incorporation may be proposed as the formation of the linkage ofthe molecules caused by intermolecular interaction between PA and Triton x100.