The study of TiO2 coating on ZnO by electrodeposition
| Autor: | Ke-Fu Liu, 劉科賦 |
|---|---|
| Rok vydání: | 2013 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 101 In this study, we have successfully coated titanium dioxide (TiO2) uniformly on the entire surface of zinc oxide (ZnO) mesoporous thin film fully by electrodeposition. First, we prepared zinc oxide thin film by spin coating method. Then we found a titanium-containing electrolyte [Ti(SO4)2] serves to accomplish our goal of the electrodeposition experiment. The way used can not only stabilize zinc oxide thin film but also coat TiO2 on ZnO thin film by varying the pH of the electrolyte and the applied voltage on ZnO. We also established electron energy model about ZnO in the titanium-containing electrolyte. When the pH of electrolyte is near 2, ZnO thin film is corroded completely when positive voltage is applied. The ZnO thin film cannot exist until applied voltage is +4V. A plentiful of TiO2 is coated on ZnO surface. When the pH of electrolyte is near 8, ZnO is not corroded by simply immersed in the electrolyte, but it is corroded by immersing in the electrolyte with positive voltage applied on ZnO. It confirms that applied positive voltage on ZnO thin film may attract acid ions of the electrolyte and then corrode the ZnO thin film. When the pH of electrolyte is near 8, ZnO with -1V applied has Ti element been detected by EDS while titanium dioxide is not coagulated on the top surface of the ZnO mesoporous film. We confirm that we have successfully made titanium-containing molecule diffused into ZnO and then converted to TiO2 uniformly throughout the internal pores by providing electron for reduction reaction. In order to make titanium-containing electrolyte having enough time to diffuse into ZnO thin film, we also used “ pulsed electroplating ” approach in our experiment. We found that when the voltage margin of 0V to -1V is chosen, the film has the highest Ti content compared with other voltage margins, which means the TiO2 coating has best change to cover the ZnO thoroughly under the condition using chose voltage margin for pulsed electroplating process. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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