OPTICAL PROPERTIES AND THE CATALYTIC ACTIVITY OF Films TiO2 AND TiO2/WO3

Reference	Presenter	Authors (Institution)	Abstract
06-053	Luana Góes Soares	Soares, L.G.(Universidade Federal do Rio Grande do Sul); BERGMANN, C.P.(UNIVERSIDADE FEDERAL DO RIO GRANDE DO SUL); Alves, A.K.(Universidade Federal do Rio Grande do Sul);	Several metal oxide semiconductors have been used in the photodegradation of organic compounds. The use of TiO2 as the most commonly used semiconductor in heterogeneous photocatalysis becomes relevant because of its efficiency in the decomposition of pollutants from water, air, bacteria, cancer cells and the degradation of toxic organic compounds. This has contributed to the production of simple molecules, such as CO2 and H2O. However, the photocatalytic capacities of TiO2 are only active in 3% of the solar spectrum, which limits its amplitude of use. Based on this, the work proposes to synthesize thin films of TiO2, and of TiO2 doped with H2WO4, by spin-coating, relating the optical and photocatalytic properties of these elements. The X-ray diffraction (XRD) technique was used to determine the crystalline structure and crystallite size. The morphology of the films was observed by scanning electron microscopy (SEM). Partial results indicate that tungsten doped films were more efficient in the degradation of methyl orange dye, indicating a higher photoactivity of this material compared to a standard catalyst. This possibly occurs due to the synchronization between the chemical and physical properties of these materials, TiO2 and WO3 when optically activated, and the position of the valence band and conduction band of WO3 in relation to TiO2, which inhibits the recombination of the couple charges electron / gap allowing the transfer of charges between the two semiconductors, increasing the efficiency of the process
<< Back