Abstract: Carbon-doped TiO2 thin films were prepared by direct current (DC) reactive magnetron sputtering at room temperature in an Ar/O2 ambience, using a titanium target incrusted with graphite pieces. The films as prepared were characterized by X-ray diffraction (XRD), UV-Vis transmission spectra, and photoelectrochemistry methods. The XRD patterns of the films showed that the doping of carbon was beneficial to the crystallization of the films. When the ratio of area of C/Ti in the target was less than 0.10, the crystallization of the films increased with the increase in graphite area in the target. The band gap of the films decreased from 3.4 eV to 3.1 eV when the ratio of area of C/Ti in the target was 0.05. The photoelctrochemical property of the films improved when the ratio of area of C/Ti in the target was less than 0.10. When this ratio was 0.10 the photocurrent density of the film was 0.069 μA·cm-2 at 0 V under visible light illumination. However, an abnormal photoelectrochemical response was observed when the ratio of area of C/Ti in the target was 0.16.

Key words: DC reactive magnetron sputtering mothed, Graphite/titaniumtarget, Carbon-doped TiO2 thin film, Photoelectrochemistry