Synthesis And Photocatalytic Oxidation Properties Of Titania Hollow Spheres

Among various oxidesemiconductor photocatalyst, titaniumdioxide has proved to be the most suitable catalysts for widespread environmental application because of its biological and chemical inertness, strong oxidizing power, non-toxicity and long-term stability against photo and chemical corrosion. However, its technological application seems limited by several factors, among which the most restrictive one is the need of using an ultraviolet (UV) light, as excitation source due to itswide band-gap. Therefore, it can only capture less than 5% of the solar irradiance at the Earth's surface. For the sake of efficient use of sunlight, or use of the visible region of the spectrum, the technology of enlarging the absorption scope of TiO₂ may then appear as an appealing challenge for developing the future generation of photocatalysts. In this article, hollow titania spheres were synthesized using the cationic polystyrene lattices which were prepared by polymerization using 2-(methacryloyl) ethyltrimethy lammonium chloride (DMC)and AIBA as initiator by the method of sol-gel.First,the mechanism of soap-free emulsion polymerization is researched and the monodisperse copolystyrene was prepared using 2-(methacryloyl) ethyltrimethy lammo- nium chloride(DMC)and the diameter is about 130 nm. FT-IR were used in the structure analysis of copolymers, The results show that the copolymer structure by synthesized was according to the expectable structure. TEM and SEM were employed in the influence analysis of the copolystyrene microspheres size and distribution.The results show that the amount of initiator(AIBA)and the monomer of (St)influence the size and the distribution of copolymer microspheres;The amount of copolymer mono- mer(DMC)little influences the size and the distribution of copolymer microsphe- res. Then,we prepared tinania nanocomposite spheres by the sol-gel method. Titania nanorods have been hydrothermally prepared using Tetrabutyl titanate(TBOT)as titanium source. SEM and TEM were employed in the influence analysis.The results show that the amount of TBT,the amount of ammonia and the amount of MTC influence the size of TiO₂ partials and the morphology of the microspheres.thirdly, hollowtinanian sphere with 10-20nm Shell thickness were prepared by removing the core of the copolystyrene by calcinations.we stutied the photocatalysis activity by the Degradation rate of the Methyl orange,we prepared anatase,rutile and the mixed of anataseand rutile hollow tinania sphere by calcinations in different tempreture,500℃,.the result showed that the anatase hollow tinania sphere by 500℃calcinations have the most high photocatalysis activity.last we comprised the photocatalysis activity between anatase hollow tinania sphere and P25,the result show hollow structure antase sphere can improved photocatalysis activity.