Graphene oxide modified TiO2 nanotube arrays: enhanced visible light photoelectrochemical properties

Novel nanocomposite films, based on graphene oxide (GO) and TiO 2 nanotube arrays, were synthesized by assembling GO on the surface of self-organized TiO 2 nanotube arrays through a simple impregnation method. The composite films were characterized with field emission scanning electron microscopy, X-ray diffraction, Raman spectroscopy and UVvis 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 TiO 2 nanotube composite electrode compared with pristine TiO 2 nanotube arrays. The sensitizing effect of GO on the photoelectrochemical response of the TiO 2 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 TiO 2 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 TiO 2 nanotube arrays. Graphene oxide modified TiO 2 nanotube arrays were fabricated and a significantly enhanced photoconversion efficiency was observed under visible light illumination.