Application of Supercritical CO2 Emulsified Electrolyte in Cathodic Deposition of Metal Oxides
Supercritical CO2 (sc-CO2) emulsified electrolyte (SCE) is known to be effective in affecting desorption rate of gas formed on the surface of cathode, and influence transfer efficiency of reactive species to the surface of cathode. Therefore, properties of the TiO2 and ZnO thin films are expected to be influenced by the properties of the emulsion.
In this work, a sc-CO2-assisted galvanostatic cathodic deposition process is developed for preparation of TiO2 and ZnO thin films with high structural uniformity. TiO2 and ZnO are deposited cathodically on a conductive substrate in a two-compartment cell under a fixed current density, in which platinum foil is employed as the counter electrode. Influences of sc-CO2 and reaction pressure on the crystal growth of TiO2 and ZnO thin films were investigated. The present synthetic approach could be further extended to obtain other metal oxide thin films such as SnO2, CuO, NiO and so on.