Preparation And Photocatalytic Studies On Tubular Polyoxometalates Loded With TiO₂

Many industries produce large amounts of organic solvent wastes, some of which arevaluable and recoverable. If these organic solvent wastes are discarded without treatment,they would pollute the environment, and the resources would be wasted. The main subject ofthis paper is to study the photocatalytic oxidation degredation of dye (methylene blue, MB) inthe presence of SiW12O404--TiO2(SiW12-TiO2) microtubes and recycling contaminated organicsolvent waste (CH3CH2OH).In this work, the SiW12-TiO2microtubes were prepared by loading TiO2on SiW12microtubes. The morphologe and structure of SiW12-TiO2microtubes were examined by FI-IR,XRD and SEM-EDS. The photoreaction processes were examined by UV-vis spectroscopy,mass spectrometry and ion chromatography detection. The photocatalytic activities ofSiW12-TiO2microtubes with different amount of TiO2loaded and different calciningtemperature are studied. Comparative experiments show that the microtubes calcined at300°C have a good photocatalytic performance than those calcined at500°C. Furthermore,photocatalyic oxidation rate of composite microtubes increased with increasing amount of Ti(IV) loaded, which play a key role in the photocatalytic process. The reaction mechanism wasalso studied. SiW12-TiO2microtubes made cleavage of the whole conjugated chromophorestructure and completely mineralize MB. It was noted that during the photocatalytic processchloride ions in methylene blue (MB) were oxidized to chlorine.Preparation and photocatalyic activity of Fe2+/Cu2+doped and Mo/V-Substituted Keggintungstosilicate microtubes loded with TiO2were also discussed. Fe2+/Cu2+-doped Keggintungstosilicate microtubes with TiO2showed a bettter photocatalytic activity.