High antibacterial activity of ultrafine TiO2/graphene sheets nanocomposites under visible light irradiation

The composites of ultrafine TiO2 nanoparticles and graphene sheets (GSs) were prepared via a direct redox reaction. Investigation of morphological features of the composite indicated that nano-sized TiO2 particles were distributed on the surfaces of GSs. The as-prepared TiO2/GSs photocatalysts possessed extended light absorption range, which could be excitated by visible light. These visible-light active photocatalysts were utilized for degradation of Escherichia coli bacteria, and their antibacterial activity against E. coli was much higher than that of pure TiO2 nanoparticles. Overall, a material with high antibacterial activity under ambient visible light illumination was developed, which could be widely used for indoor air disinfection. (C) 2012 Elsevier B.V. All rights reserved.