Facile deposition of carbon-doped TiO2 films by two-electrode electrodeposition setup

Abstract

This study presents a simple electrochemical deposition route to obtain carbon-doped TiO2 films. The deposition of the films is carried out on silicon substrates from a mixture of methanol (CH3OH) and Titanium (IV) isopropoxide (Ti[OCH(CH3)(2)](4)) solution using a simple two-electrode electrodeposition setup. The obtained films are characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-Visible diffuse reflectance spectroscopy (DRS) and conductivity measurements. Depending on the deposition conditions, both amorphous and crystalline TiO2 films could be obtained. It is found that carbon is doped both substitutionally and interstitially. High carbon doping (up to 18.96%) enables to obtain TiO2 film with narrowed bandgap and high conductivity to about 2.3 eV and 1.19 x 103 S cm(-1), respectively. This study suggests that the proposed electrodeposition route offers an easy way of obtaining conductive and narrowed bandgap TiO2 films on large surface areas.