Study On The Preparation And Properties Of Several Attapulgite-Based Photocatalysts

In this study, we focused on the synthesis of attapulgite(ATP)-based photocatalysts and their photocatalytic performance. This thesis includes the following three parts:(1) Ag/AgBr/ATP nanocomposites:ATP was first calcined and then treated with HCl. Ag/AgBr/ATP photocatalysts were synthesized by a deposition-precipitation method using [Ag(NH3)2]+solution as the silver resource and cetyl trimethyl ammonium bromide (CTAB) as both bromine source and surfactant. The obtained samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), UV-visible diffused reflectance spectroscopy (UV-vis DRS) and X-ray photoelectron spectra (XPS). The photocatalytic activities of these samples have been investigated as a function of loading amount and photo-reduction time, respectively. The results showed that the diameters of Ag/AgBr particles in Ag/AgBr/ATP were much smaller than pure Ag/AgBr and the photocatalytic activities of Ag/AgBr/ATP were higher than that of pure Ag/AgBr. The best ratio of Ag+to ATP is2.0mmol/g and the optimum photo-reduction time is10min for the as-prepared Ag/AgBr/ATP nanocomposites to achieve enhanced photocatalytic efficiency.(2) a-Fe2O3/ATP nanocomposites:Pretreated ATP was used as the raw material. We fabricated a-Fe2O3/ATP nanocomposites via two different methods. The obtained samples were characterized by XRD, TEM and UV-vis DRS. The effects of a-Fe2O3amounts on photocatalytic activity were evaluated by the photodegradation of methylene blue. The characterization showed that the diameters of the a-Fe2O3particles which were loaded on ATP supports were very small and a-Fe2O3/ATP nanocomposites showed a better photocatalytic performance than pure a-Fe2O3. When the weight ratio of a-Fe2O3to ATP=20wt%, the a-Fe2O3/ATP nanocomposites displayed the highest photocatalytic activity.(3) CuO/ATP nanocomposties:Pretreated ATP was used as the raw material. CuO/ATP nanocomposties were successfully synthesized by a simple solvothermal method using CuCl2and oxalic acid as reagents, and the influences of CuO amounts on the photocatalytic activity of as-synthesized samples were also investigated. We employed XRD, TEM, UV-vis DRS and XPS to characterize as-obtained samples. The results showed that CuO particles were uniformly loaded on ATP supports and their diameters were much smaller than that of the CuO particles in previous researches. When the weight ratio of CuO to ATP=10wt%, CuO/ATP nanocomposites showed the best photocatalytic performance.