Synthesis of TiO₂-Reduced Graphene Oxide Nanocomposites Offering Highly Enhanced Photocatalytic Activity.

Abstract

Photogenerated electron-hole recombination significantly restricts the catalytic efficiency of titanium dioxide (TiO₂). Various approaches have been developed to overcome this problem, yet it remains challenging. Recently, graphene modification of TiO₂ has been considered as an effective alternative to prevent electron-hole recombination and consequently enhance the photocatalytic performance of TiO₂. This study reports an efficient but simple hydrothermal method utilizing titanium (IV) butoxide (TBT) and graphene oxide (GO) to prepare TiO₂-reduced graphene oxide (RGO) nanocomposites under mild reaction conditions. This method possesses several advantageous features, including no requirement of high temperature for TiO₂ crystallization and a one-step hydrothermal reaction for mild reduction of GO without a reducing agent, which consequently makes the production of TiO₂-RGO nanocomposites possible in a green and an efficient synthetic route. Moreover, the as-synthesized nanocomposites were characterized by numerous advanced techniques (SEM, TEM, BET, XRD, XPS, and UV-vis spectroscopy). In particular, the photocatalytic activities of the synthesized TiO₂-RGO nanocomposites were evaluated by degrading the organic molecules (methylene blue, MB), and it was found that the photocatalytic activity of TiO₂-RGO nanocomposites is ~4.5 times higher compared to that of pure TiO₂. These findings would be useful for designing reduced graphene oxide-metal oxide hybrids with desirable functionalities in various applications for energy storage devices and environmental remediation.