A series of Mutil-Walled Carbon Nanotube (MWCNT) nanocomposite film electrodes with different amounts of MWCNT were prepared by a sol-gel method. The microscopy and the structure of the nanocomposite film were characterized via scanning electron microscopy (SEM) and X-ray diffraction (XRD). The photoelectrochemical properties of the nanocomposite film electrodes were investigated under white and visible light illumination using KOH as electrolyte. The results showed that the photovoltage and photocurrent of MWCNT/ TiO₂ nanocomposite film electrodes could be evidently enhanced compared with a pure TiO₂ thin film electrode. The photoelectrochemical response under visible light region was also observed for such nanocomposite film electrodes. The charge transfer rate and the total absorption of simulated solar light were remarkably increased because of the presence of MWCNT thin film, which has a superior electron-conducting property, an absorption property and a tanglesome network, providing an ideal matrix for uniform distribution of TiO₂ nanoparticles. It was found that the appropriate amount of MWCNT in the nanocomposite film electrode was 0.04 mg/cm².

Key words: TiO₂, MWCNT, photoelectrochemical property, visible light