Study On Preparation Of Nitrogen Doped Titanium Dioxode And Photocatatalytic Degradation Of Dye Reactive Red Violet By Nitrogen Doped Titanium Dioxode

The titania dioxide(TiO₂) which has the properties of better steady of chemistry,low cost,nontoxicity etc is becoming the best potential appliance in the photocatalysts.However,the band gap of TiO₂ is 3.2ev and the photocatalytic reaction proceeds under the UV illumination with wavelengths shorter than 387.5nm.Nitrogen doped TiO₂ may shifting the optical response from the UV to the visible spectral range,enhancing the use efficiency of sunlightIn the paper,SG,TN series nitrogen doped titania dioxide(N/TiO₂) nanosize particles were prepared by sol-gel technics and hydrolyzing product of tetra-n-butyl titanate(TNB) with ammonia respectively.TNH series N/TiO₂ were prepared by H₂O₂ modified the precursors of hydrolyzing TNB.The best preparation condition of N/TiO₂ is obtained by single factor analysis and orthogonal experiment.The Photocatalytic activities of the N/TiO₂ catalysts were evaluated under ultraviolet and visible light irradiation by photodegradation of Reactive Red violet,The surface structural,photoelectric properties and mechanism of influence induced by nitrogen doping on photocatalytic performance of N/TiO₂ are characterized by X-ray Diffraction analysis(XRD),Element analysis (EA),Thermogravimetric analysis(TG),Infrared Spectroscopy(IR) and Ultraviolet-Visbile light Diffraction Reflection Spectrum(DRS).The results shows that the nitrogen doping were being in the three series N/TiO₂,The highest doping quantity reaching 0.2%,also the ration H₂O₂ modification and processing by filtering were advantageous to enhancing the quantity of nitrogen doping.Simultaneously infers that the O site in TiO₂ lattice is substituted N atom,forms the displacement doping in the TN series photocatalyst,but there are may be two kinds nitrogen doping in the TNH series N/TiO₂,one is O site was substituted N in TiO₂ lattice, another is gap doping which N^+x and O union forms the Ti-O-N key.The DRS analysis shows that the highest visible light absorption rate of H₂O₂ modified N/TiO₂ reaching 80%,it enhanced the visible light absorption intensity obviously.The photocatalytic activity of N/TiO₂ which prepared by hydrolyzing TNB method and H₂O₂ modified approach compared with P25-TiO₂ was studied in the same condition.The results show that TN,TNH series N/TiO₂ exhibited stronger photocatalytic activity than that of P25 under visible light irradiation,and the TN sample exhibited the same photocatalytic activity with P25 under UV irradiation;but decolorization process of the sample which prepared by the sol-gel system were adsorption primarily。The optimum degradation reaction condition of the reactive red violet under UV irradiation and the catalyst separation and returns-ratio in reactor under the N/TiO₂ suspension system were also studied.The specific gravity of N/TiO₂ particles that prepared by H₂O₂ modified is bigger and easy to deposition,the returns-ratio is more than 90%by utilizing simple process operation as depositing and membrane separation...