Constructing graphene/InNbO4 composite with excellent adsorptivity and charge separation performance for enhanced visible-light-driven photocatalytic ability

Graphene (Gr)/InNbO4 composite with visible light response was fabricated by a facile one-step hydrothermal method. The prepared samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and diffuse reflectance UV-viss spectra (DRS), respectively. The results indicated that InNbO4 particles with monoclinic type mainly distributed on the Cr sheet uniformly. The samples had good visible light response. Photocatalytic degradation of Methylene Blue (MB) was conducted under the visible light irradiation (>400 nm) in order to evaluate the photoactivity of this photocatalyst. The kinetic constant of MB removal with Gr/InNbO4 (0.0346 min(-1)) was 1.87 times that with InNbO4 (0.0185 min(-1)). The enhanced photocatalytic performance of Gr/InNbO4 was attributed to the improved adsorption performance and the separation efficiency of the carriers. With Gr/InNbO4 as the photocatalyst the (OH)-O-center dot radicals be another type of oxidant in the photocatalytic process in addition to holes and electrons on Cr transporting from InNbO4 participated the oxidation of MB adsorbed on Cr. Overall, the result of this work could provide a new way of the construction of a visible-light-driven photocatalyst with high performance. (C) 2011 Elsevier B.V. All rights reserved.