| At present, TiO2restraining the recombination of the electronic and the cavities, which can improve the photon quanta, is one of the important research subjects in photocatalysis field. Meantime, TiO2immobilized to solve the problem of separation and recycling is also currently the research hot spots. In this dissertation, research was carried out for the hot spots.Firstly, alkaline earth metal ions Mg2+, Ca2+, Sr2+and Ba2+doping TiO2photocatalyst M2+-TiO2was prepared by the sol-gel method. The catalyst samples were characterized by XRD and FT-IR to obtain the crystal and surface state. Malachite green(MG) was used in the study of photocatalytic properties It was founded that the doping if M2+enhances ultraviolet activity of TiO2. The optimum doping of Mg2+, Ca2+, Sr2+and Ba2+is0.6%,1.0%,1.0%and1.0%. Forthmore, Mg-doped of TiO2remarkably improved the photocatalytic activity of TiO2for MG degradation. The influencing factors such as initial concentration of MG, catalyst addition amount were studied respectively. The degradation rate of MG solution(30mg-L-1, pH=7.0) reached88%over0.6%Mg-doped of TiIO2(1.Og-L-1) in120min under the irradiation of ultraviolet light, and the catalytic reaction mechanism was forecasted.Secondly, La and Ce co-doping TiO2was synthesized by the chemical liquid precipitation method using [Hmin]PF6(1-hexyl-3-methyl-imidazolium hexafluoro phosphate)-water mixture as solvent. Various studies such as X-ray diffraction(XRD), scanning electron microscope(SEM), fourier transform infrared spectroscopy(FT-IR) were conducted, and photocatalytic degradation tests were carried out with mthyl orange. La-Ce doping and [Hmin]PF6restrain TiO2from the anatase to the rutile. The pseudo-first-order rate constant(k=0.02078min-1) was4.2,1.3and1.7times that of anatase TiO2, La-TiO2and Ce-TiO2. The effect is okay when NOBACRONR Yellow, Olive and Navy was photo-degradated by using2%La-0.04%Ce-TiO2photocatalyst.Thirdly, TiO2/AC photocatalyst with different loading contents was prepared by sol-gel method with activity carbon(AC) as the carrier and characterized using XRD, SEM and FT-IR. Results of structural characterization indicated that the prepared samples were all pure anatase phase TiO2and pores structure were clearly displayed. Results of FT-IR analysis revealed that Ti-O-C was bringed out in1100cm-1. The optimal photocatalytic oxidation conditions of MG are400℃of calcinations temperature,30%of the amount of TiO2loaded on activitied carbon,1.5g-L-1of the amount of photocatalyst and initial concentration of50mg-L-1(pH=7.0) MG solution. The TiO2/AC photocatalyst had excellent degradability resistance and reproducibility. |
