Enhanced photocatalytic performance and impact of annealing temperature on TiO2/Gd2O3:Fe composite

This work relates to an experimental study concerning the elaboration of the composite material TiO2/Gd2O3:Fe (TiO-Gd:Fe) from powders of Gd2O3 and TiO2 via a ball milling process with different annealing temperatures. The micro-structural and morphological characterizations of the ground Gd2O3-TiO2 mixture as well as the measurements of the optical properties were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR) and UV-Vis diffuse reflectance spectroscopy. The X-ray results of the TiO-Gd:Fe composites reveal the presence of the TiO2 anatase phase in addition to the Gd2O3 phase. The direct band-gap of TiO-Gd:Fe sample is 3.22 eV for the 350 degrees C composite and 3.45 eV for the 600 degrees C composites. The results of FTIR spectroscopy confirm the presence of the TiO2 phase. The results of the photocatalytic tests of the composites show the (C - C-0)/C-0 ratio goes from 0.05 to 0.71 when the annealing temperature goes from 350 to 600 degrees C.