Abstract
This study presents a solution containing titanium trichloride and excess sodium nitrate used as a novel solution to deposit titanium dioxide films. The mechanism of cathodic deposition of titanium dioxide is examined by means of linear sweep voltammetry (LSV), ultraviolet-visible spectroscopy (UV-VIS), and in-situ ultraviolet-visible spectroscopy (in-situ UV-VIS). Based on the understanding about the growth mechanism of cathodically deposited titanium dioxide, hydrogen peroxide solution is used to modify the deposition bath and to enhance the deposited rate of titanium dioxide. The examinations of electrochemical quartz crystal microbalance (EQCM) and cyclic voltammetry (CV) prove the deposition rate in modified deposition bath is faster than that in before deposition bath, and the morphology and crystallinity are analyzed by scanning electron microscope (SEM) and x-ray diffraction (XRD). The forementioned novel plating bath is applied in a dual-electrode system to prepare titanium dioxide films. In this work, the morphology of titanium dioxide can be controlled by bath temperature and deposition mode. The electrochemical characteristics of dual-electrode system and temperature effect are examined by LSV, and the microstructure of titanium dioxide is analyzed by SEM. Moreover, this work demonstrates that various pulse times, relaxation times and frequencies can be adjusted to control the morphologies of titanium dioxide films. Morphology and particle size of titanium dioxide films, examined by means of SEM, is effectively controlled by change the pulse parameters. The analysis of XRD confirmed that well-crystalline titanium dioxide in pure anatase phase is prepared after the heat treatment.