Research On Preparation Of TiO₂/CdS/Fe_mO_n In Reversed Micro Emulsion And Photo Catalysis Degradation Of Methylene Blue

The property, principles and applications of the semiconductor nonmaterial are introduced. It is especially reviewed here that the modification of photo catalyst and its contribution to water treatment. We've found few reports on TiO2/CdS/FemOn prepared in reversed micro emulsion because of the difficulty in realizing the equably equally dispersion. The preparation of TiO2/CdS/FemOn in reversed micro emulsion was attempted and finished after choosing the right system. The size and coated structure were characterized by UV-vis, IR, XRD and Interfacial electric property. With the references of former studies, the investigation is processed in the visible light photo catalysis. The research includes following two sections.1. TiO2/CdS/Fe3O4 preparation in reversed micro emulsionBy determining the conductivity of the reversed micro emulsions of diversified component ratios, the right was found. TiO2/CdS/Fe3O4 were prepared in reversed micro emulsion which was made up of Brij35/n-hexanol/cyclohexane/water (salt solution). The conductivities of the micro emulsion system Brij35/n-hexanol/ cyclohexane/water (salt solution) is related to salt concentration and volume ratios of water to oil. The absorption of TiO2/CdS in the range of visible light is stronger than the sum of CdS and TiO2. Absorption of TiO2/CdS/Fe3O4 is near to that of TiO2/CdS. Fe3O4 doesn't weaken the compound's absorption in visible light. The preparation impacts the compound particle IEP. The IEP shifts toward low pH with addition of CdS and FemOn, and shift toward high pH with calcinations temperature rising.2. Photo catalysis of TiO2/CdS/FemOnPhoto catalytic properties of the ultra-fine particle TiO2/CdS/FemOn are investigated by examining the degradation of methylene blue in diversified lamp-houses. The compound particle shows better effects than TiO2 nanopaticle(50nm) on adsorption, ultra-light degradation and sunlight degradation. The factors such as preparing condition, ratio of reactants and changes of light kind and intensityinfluence its photo catalysis. In ordinary sunlight, 90 per sent of methylene blue solution (20 ppm) has been degraded within 30 min. The rate of reaction speeds faster with increase of light intensity. It works better in ultra-light than in sunlight at the same light intensity. Reaction kinetics is discussed here. Under low density condition, The degradation of methylene blue is reaction of the first order.The interfacial electric behavior of compound particles is studied. The zeta potential indicates the adsorption and degradation of methylene blue on compound particles in the reaction.TiO2/CdS/FemOn brings Fe3O4 and - Fe2O3 to the catalyst which have magnetism . We can separate the catalyst from reversed micro emulsion with outside magnetic power. After recycling twice, the catalyst still decomposes 80per sent of methylene blue solution (20ppm) within 50 min.