Studies On Rare Earth Doping And Radiated Modification Of Magnetic Photocatalyst

Photocatalytic technology is a new method and has extensive applied foreground in wastewater treatment. TiO₂ is believed to be the most promising material because of its low price, nontoxcity, long term stability in aqueous solution.At present, the research about TiO₂ form has two tendencies: one is TiO₂ power, another is TiO₂ membrane. Because of its limit surface area, the immobilized TiO₂ membrane has been demonstrated to lower photocatalytic activity than TiO₂ power. But TiO₂ power is difficult to be separated from aqueous reactant systerm. It is at big lost rate in separation process due to its small particle diameter. In order to solve separation and reuse of TiO₂ power, magnetic photocatalyst has been prepared in our laboratory. However, the photocatalytic efficiency has been decreased by the addition of magnetic support. In this paper, we do research on rare earth doping and radiation modification of magnetic photocatalyst in order to enhance its activity.By using micro-sized Fe3O4 as support, SiO₂ isolated layer is coated on the surface of Fe3O4 via sol-gel method, followed by dryness and pestled treatment. On the surface of SiO₂/Fe3O4, TiO₂ particles are coated while rare earth nitrate is added, followed by dryness, calcinations, and pestled treatment.Photocatalyst La doped is put into Co-60 radiation equipment (Tianjin Institute of thechnology and physics). Then the radiated modification is investigated. Photocatalyst under different dosage are obtained by changing radiation time.With ezao-dye as object contamination, photocatalytic activity of modificated samples is evaluated. The result showed that photocatalytic activity was enhanced by different degree, when different kinds of rare earth(RE=La,Nd,Gd) were doped. And photocatalytic activity of material changes with different concentration of rare earth.By radiation, photocatalytic activity of material is enhanced. In this paper, the curve of photocatalytic activity, as function of radiation dosage, is obtained. Its theoretical analysis is processed.