Graphene oxide modified TiO2nanotube arrays: enhanced visible light photoelectrochemical properties

Abstract

Novel nanocomposite films, based on graphene oxide (GO) and TiO₂ nanotube arrays, were synthesized by assembling GO on the surface of self-organized TiO₂ nanotube arrays through a simple impregnation method. The composite films were characterized with field emission scanning electron microscopy, X-ray diffraction, Raman spectroscopy and UV–vis diffuse reflectance spectroscopy. The photoelectrochemical properties of the composite nanotube arrays were investigated under visible light illumination. Remarkably enhanced visible light photoelectrochemical response was observed for the GO decorated TiO₂ nanotube composite electrode compared with pristine TiO₂ nanotube arrays. The sensitizing effect of GO on the photoelectrochemical response of the TiO₂ nanotube arrays was demonstrated and about 15 times enhanced maximum photoconversion efficiency was obtained with the presence of GO. An enhanced photocatalytic activity of the TiO₂ nanotube arrays towards the degradation of methyl blue was also demonstrated after modification with GO. The results presented here demonstrate GO to be efficient for the improved utilization of visible light for TiO₂ nanotube arrays.