Preparation of TiO2/single layer graphene composite films via a novel interface-facilitated route

Abstract

Titanium dioxide/single layer graphene (TiO2/SLG) composites have been widely studied due to the role of graphene acting as an electron-acceptor, which can suppress the recombination of photogenerated electron–hole pairs from TiO2 upon light irradiation. In this study, a novel route for the synthesis of TiO2/SLG composite films using controlled experiment chemical vapor deposition combined with magnetron sputtering is reported for the first time. The structure and morphology of the SLG and TiO2/SLG composites were characterized by scanning electron microscopy, Raman spectroscopy, transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The results showed that the introduction of SLG layer influenced the crystalline structure, morphology and photocurrent of the TiO2 films. The interaction between TiO2 and SLG and p-doping of SLG were demonstrated by the G band splitting and upshift of the 2D band. With the higher quality of SLG as the interface of the TiO2/SLG, the composite films exhibited improved photocurrent and reached the highest of about 3.25 μA/cm−2. The results suggested the high separation efficiency of photogenerated electron-hole pairs, which could inspire continuous researches of energy conversion and environmental applications.