Nanostructuring Cadmium Germanate Catalysts for Photocatalytic Oxidation of Benzene at Ambient Conditions

A nanostructured Cd2Ge2O6 photocatalyst was successfully prepared by a hydrothermal process. The photocatalyst was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV/vis, N-2 adsorption-desorption, and Fourier transform infrared (FTIR) techniques. The photocatalytic property of the material was evaluated via the decomposition of benzene in the gas phase with light illumination and was compared with that of commercial titania (Degussa P25) and Pt/TiO2. The electronic band structure of Cd2Ge2O6 was analyzed by density functional theory (DFT) calculation. Results reveal that the prepared Cd2Ge2O6 has unique geometric and electronic properties, which in combination with its superior textural properties makes it a new semiconductor photocatalyst for environmental purification of benzene in air with molecular oxygen under ambient conditions. It was also found that the Cd2Ge2O6 was more active and stable than TiO2-based catalysts in the photocatalytic decomposition of other volatile aromatic pollutants including toluene and ethylbenzene. The enhanced photocatalytic performance of Cd2Ge2O6 Can be explained by the special band structure, and geometric and electronic feature, in unison with the high surface area nanoporous framework.