Electrocrystallization of cadmium on anodically formed titanium oxide

The electrocrystallization of Cd on previously anodized Ti substrates was studied by means of electrochemical techniques and SEM images in three different solutions of CdSO₄ (2, 10, and 50 mM). Voltammetric characterization showed the typical behavior of metal electrodeposition on conducting substrates, and potentials for electrodeposition of Cd were identified. However, the response obtained at different potentials in current transients exhibited an abnormal behavior suggesting the influence of TiO₂ on the process of electrocrystallization. The characterization of the obtained electrodeposits by SEM images allowed relating electrochemical with morphological changes, in particular, variations in the crystal size and shape as well as formation of presumably Cd branches on the substrate surface. This behavior only allowed the analysis of current transients of the electrodeposits obtained in 2 mM CdSO₄ solution using general equation for diffusion-controlled 3D growth and relating parameters of Cd crystal growth on anodized Ti electrode with the observed morphological changes.