Graphene Grown on Anatase-TiO2 Nanosheets: Enhanced Photocatalytic Activity on Basis of a Well-Controlled Interface

To achieve a best promotion effect of photocatalytic activity, an optimized interface between graphene and TiO2 is highly desirable, which is, however, difficult to realize via conventional preparation of the graphene/oxide composites. To this end, we here develop a novel strategy to directly grow graphene on the anatase-TiO2 (a-TiO2) nanosheet via an ambient pressure chemical vapor deposition (AP-CVD) method using acetylene as the precursor. Such a recipe successfully avoids the intercalating contaminations, meantime ensures the contact uniformity of graphene over a-TiO2 (G/a-TiO2). The ultrafast transient absorption spectroscopy clearly reveals the efficient charge transfer from TiO2 to graphene in assisting the separation of photoinduced electron hole pairs. Moreover, the measurements of photo current and the photocatalytic degradation of methyl orange turn out that the composite with double layer graphene shows the best performance, which can possibly result from the competition of interlayer interactions within the multilayer graphene and the interactions between graphene with TiO2.