One-pot hydrothermal synthesis of TiO2/graphene nanocomposites for enhanced visible light photocatalysis and photovoltaics

Abstract

Two dimensional (2D) nanostructures such as graphene have been attracting increasing research interest in the recent past due to their superior material properties. Herein, we report a facile and scalable method for the production of a few layered graphene sheets and the synthesis of TiO₂ nanoparticles on the surface of the prepared graphene sheets using a single step hydrothermal method. The composites prepared with different graphene loading were assessed for their photocatalytic degradation ability under visible light and in dye sensitized solar cells (DSC). The results showed that the average thickness of the obtained graphene sheets was 1.1 nm and the TiO₂ nanoparticles were uniformly dispersed on the surface of the graphene. In the photodegradation of methyl orange (MO), the photoactivity of the composite (with 10 wt% graphene loading) was found to be three times better than bare TiO₂ nanoparticles. This increased activity is due to the synergistic effects of TiO₂ nanoparticles and graphene sheets. For DSC, composites with 0.7 wt% graphene loading showed a maximum efficiency of 4.26%, 25% higher than without graphene.