Effects of Annealing Atmosphere on the Structures and Photocatalytic Properties of Gd-Doped TiO2/CF Photocatalysts

In the present investigations, sol-gel method was utilized to prepare Gd-doped TiO2/CF precursor and then the Gd-doped TiO2 precursor was loaded on the PAN-carbon fiber (PAN-CF) substrates via the dip-coating process. Superheated steam, nitrogen and air atmosphere were chosen for the annealing treatment of the material, respectively. Field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) were used to characterize the surface morphology of the composites and crystal phase of Gd-doped TiO2. The photocatalytic properties of the Gd-doped TiO2/CF annealed under different atmosphere were investigated by degrading acid orange II under UV irradiation. The results indicate that the annealing atmosphere has significantly effects on the structures and photocatalytic activity of the thin films. The Gd-TiO2/CF annealed under superheated steam atmosphere exhibits the highest photocatalytic activity. The XRD analysis suggests that all of the samples were in the anatase form after calcinations at 550 degrees C.