Electrochemically assisted self-assembling of ZnF₂-ZnO nanospheres: Formation of hierarchical thin porous films

The present work demonstrates the anodic formation of ZnF₂-ZnO nanosphere layers by anodization of a zinc substrate in a fluoride containing 2-methyl-1,3-propandiol electrolyte at the substrate temperature ranging from -2°C to -30°C. The anodically grown films were characterized using FE-SEM, EDX, XPS and XRD techniques. Thermal oxidation of the film at 300°C leads to the conversion of all ZnF₂ into crystalline ZnO, together with the partial fusion of nanospheres and expansion of the grains. The electrical resistance of the films was found to depend on fluoride content and crystallinity.