Photocatalytic Degradation Of Methylene Blue Solution By Titania Supported On Diatomite And Micro-crystal Muscovite

In this paper, TiO₂-loaded on the natural fine dispersed minerals composite photocatalyst was prepared by Sol-Gel process using diatomite, micro-crystal muscovite and zeolite as the supporter and tetranbutyl titanate as the titanic source. The photocatalytic properties of TiO₂/mineral sample in the Methylene Blue solution as dyeing wastewater in one of the typical organic pollutants were investigated. This research has the significant environment significance to deal with the textile printing pollutant primarily.The sample synthesis preparation condition and the technological parameter are optimized through XRD, SEM, Laser grain-size distribution and other modern tests of the instruments, methods and means, to study the relationship between the structure and composition of samples and the photocatalytic properties of TiO₂/mineral sample. XRD patterns and SEM photographs analysis showed that nano-TiO₂ on the surface of the mineral carrier is good and the roasting temperature of the sample preparation phase of the decisive role. 450℃and 600℃were roasting 2h samples, 450℃roasting obtains the sample to be pure anatase nano-TiO₂ diffraction peak primarily in the XRD spectrogram, 600℃of a sample of the massive rutile diffraction peaks shows that have been part of anatase nano-TiO₂ started to transform for rutile nano-TiO₂.The influence of UV light on Methylene Blue and the role of nano-TiO₂ powders, diatomite, micro-crystal muscovite, and TiO₂ loaded mineral in the Methylene Blue solution were investigated. The result indicated: without UV irradiation the nano-TiO₂ powders has better photocatalytic activity for decomposition of Methylene Blue and the mineral has an excellent absorption; The TiO₂/mineral compound photocatalyst is stronger function than nano-TiO₂ or the mineral to the Methylene Blue solution, which is to be the decomposition of nano-TiO₂ as well as the absorption of mineral combined action, but later result primarily. UV irradiation can improve the nano-TiO₂ photocatalytic activity, obviously enhance the TiO₂/mineral composite photocatalyst photocatalytic activity; The degradation rate of Methylene Blue Solution by TiO₂/mineral compound photocatalyst is higher than sole nano-TiO₂ and the sole mineral under UV irradiation. Compared with the absorption performance of diatomite, micro-crystal muscovite and zeolite in Methylene Blue solution, diatomite has the intensive absorptive capacity, the absorption rate to reduce along with the mineral granularity increase by Laser grain-size distribution. The effect of mineral absorption, irradiation condition, the mineral grain size, TiO₂ amount on mineral, roasting temperature of TiO₂/ diatomite photocatalyst, catalysts concention and the Methylene Blue of initial concention were studied. The result indicated: The absorption of minerals is greater, the photocatalytic degradation ability of TiO₂/mineral composite photocatalyst to the Methylene Blue solution is stronger. TiO₂/mineral composite photocatalytic activity is increased along with the mineral particle size decreased. When TiO₂ amount on mineral is 20wt%, 25wt%, 33wt%, 50wt%, 67wt%, by 50wt%, after 450℃roasting has the highest photocatalytic activity under the ultraviolet ray illumination. The degradation rate of the 100 mL Methylene Blue solution with 5mg/L concentration is about 100% under UV irradiation for 4h at room temperature used TiO₂ /mineral as photocatalyst with concentration of 2.5g/L.