Electrodeposition of Zn-TiO2 nanocomposite films-effect of bath composition

Zn - TiO2 nanocomposite films were prepared by pulsed electrodeposition from acidic zinc sulphate solutions on a Ti support. The influence on the composite structural and morphological characteristics of Zn2+ and TiO2 concentrations in the deposition bath has been investigated. The characterisation of the samples was made by X-ray diffraction and scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM/EDS). For all the obtained coatings, the anatase and rutile phases' most intense diffraction lines were observed between 24 degrees and 28 degrees 2 theta, confirming the formation of the Zn - TiO2 nanocomposite. X-ray diffraction data show that the presence of the TiO2 nanoparticles plays a remarkable influence on the preferred orientation of the metal matrix. For the more diluted solution, a dependence between the metallic matrix grain size and the concentration of TiO2 in bath is observed. The grain size decreases with the increasing on the nanoparticle amounts. The SEM results for Zn and Zn - TiO2 deposits indicate that the nanoparticles have a strong influence on the deposit surface morphology, which is caused by the changes on the deposition mechanism.