Dynamic Template Assisted Electrodeposition of Porous ZnO Thin Films Using a Triangular Potential Waveform

Without the use of surfactants, a uniform and porous structure zinc oxide film has been synthesized in a chloride electrolyte using a triangular potential waveform. The triangular waveform parameters have been determined based on the findings of the linear sweep voltammetry and the cyclic voltammetry in the chloride electrolyte. The mechanism for producing the porous ZnO film can be attributed to the anodic current that dissolves the metallic zinc grains to form nanosized pores and, more importantly, the Cl- ions in oxidation reactions and the ZnCl+ ions in reduction reactions that cyclically function as dynamic templates for the pinning effect and the blocking effect on the zinc oxide film, respectively. The study is of significance not only in successfully developing a promising alternative for synthesizing porous ZnO films but also in understanding the underlying mechanism by the concept of dynamic templates. The findings of the paper also lay clown a good foundation for further developing this technique into practical use.