▎ 摘　　要

GO-TiO2 photocatalysts were prepared using titanium dioxide (TiO2) samples obtained by physical mixing of different amounts of anatase and rutile. The anatase/rutile mixtures were then supported by graphene oxide (GO) or reduced graphene oxide (rGO). The photocatalytic activity of these materials was investigated in the photodegradation of formic acid as a model reaction under UV/A light irradiation. (r)GO-TiO2 samples containing both anatase and rutile phases show higher activities than pure anatase, the maximum being reached with 88% anatase and 12% rutile. This synergism observed between anatase and rutile is amplified when graphene oxide is added, particularly under its reduced form. This enhancing effect was explained mainly in terms of electron transfer from anatase to rutile and then to graphene oxide or reduced graphene oxide. In this respect, partial reduction of graphene oxide appears as a remarkable way to avoid recombination of photogenerated electron-hole pairs. However, interestingly, the charge transfer is efficient only if rutile is present in TiO2 samples. (C) 2017 Elsevier B.V. All rights reserved.