Enhanced photocatalytic activity of graphene oxide decorated on TiO2 films under UV and visible irradiation

Photocatalytic TiO2 films were prepared using RF magnetron sputtering and three kinds of graphene oxide (GO) solutions with different concentration of 0.05 mg GO, 0.03 mg GO, and 0.01 mg GO in 10 ml ethanol were coated on TiO2 films, respectively. Structures and morphologies of the samples were examined by AFM, SEM, and Raman and photocatalytic properties under UV and visible irradiation were examined respectively. The efficiency of the photodegradation is enhanced when TiO2 thin film was coated with GO, it is related to its giant π-conjugation system and two-dimensional planar structure and efficient charge separation by coating GO. The maximum photodegradation rate was observed for TiO2 thin film coated with 0.03 mg GO. It is attributed to the increase of absorbance and scattering of photons through excess carbon in the photosystem.