The role of graphene oxide content on the adsorption-enhanced photocatalysis of titanium dioxide/graphene oxide composites

Titanium dioxide/graphene oxide composites were prepared using a simple colloidal blending method. Superior adsorption and photocatalysis performance under both UV and visible radiation were achieved in the presence of the composites rather than in pure TiO2. Gradually increasing the content of graphene oxide up to 10 wt% promoted the removal efficiency and correspondingly, facilitated the photodegradation rate of methylene blue. The good photocatalytic performance on the TiO2-graphene oxide composite systems irrespective of light sources could be attributed to a synergy effects including the increase in specific surface area with graphene oxide amount as well as the formation of both pi-pi conjugations between dye molecules and aromatic rings and the ionic interactions between methylene blue and oxygen-containing functional groups at the edges or on the surfaces of carbon-based nanosheets. Graphene oxide worked as the adsorbent, electron acceptor and photosensitizer to efficiently enhance the dye photodecomposition. (C) 2011 Elsevier B.V. All rights reserved.