Crystallization and Photocatalytic-activity of TiO_2 Doped with Metal Ions Prepared by Adsorption Phase Synthesis

摘要

TiO_2 photocatalysts doped with different metal ions were prepared by adsorption phase synthesis. The influence of different dopant metal ions with various concentrations on the crystallization of TiO_2 was ex-plored by XRD. Then photodegradation experiments of methyl-orange were employed to evaluate the activity of these photocatalysts. The results indicated that the crystallization of TiO_2 was restricted after doping, due to replacement of Ti~(4+) in TiO_2 lattice structure by other metal ions. And the restriction became stronger with radius and concentration of doping ions increasing. There was an optimum dopant concentration appeared during preparation of TiO_2 doped with Cd~(2+) and Fe~(3+). When dopant concentration was less or more than this optimum value, the photocatalytic activity of TiO_2 doped with metal ions was lower than that of TiO_2 without doping. Since radius of Fe~(3+) was close to Ti~(4+), the influence of Fe~(3+) dopant concentration on crystallization and activity of TiO_2 was more obvious than that of Cd~(2+) doping.