钒掺杂TiO2/AC负载催化剂的制备及光催化活性

以TiO2为主要成分的光催化剂的研究已日益受到人们的广泛关注1-6]。但TiO2粉末的回收和流失问题难以解决,固定化TiO2负载催化剂的研制是解决这一问题的有效手段2-6]。从实际应用的观点看,TiO2的光催化剂活性还有待进一步提高。研究发现,大多数过渡金属离子和少数非金属离子的

Preparation and photocatalytic activity of V-doped TiO2/AC supported catalysts

V-doped TiO_2/AC supported catalysts were formed on the surface of active carbon(AC) by sol-gel method from ammonium metavanadate and tetrabutylorthotitanate,and characterized by X-ray diffraction(XRD) and UV-vis spectrophotometry.The photocatalytic activities of the supported catalysts were evaluated in photo-degradation of methyl orange and omethoate aqueous solutions,respectively.The results showed that both the rutile phase and anatase phase are formed.The supported catalyst showed the highest photocatalytic activity at the mass fraction of V in TiO_2 of 1.5%.The band edges in UV-vis spectra of the V-doped TiO_2/AC supported catalyst showed a red-shift compared with un-doped membrane;but there was no certain correlation between these red-shifts of band-edges and the photocatalytic efficiency of the supported catalyst.In photocatalytic degradation,electrons may be transferred directly from the reactant to the conductive band of V_2O_5 and so the mechanism of the degradation was changed.Electrons that transferred to the conductive band of V_2O_5 may be excited by irradiation to the conductive band of TiO_2 and be captured by O_2.However,they may also be transferred to the valence band of TiO_2 and recombine with photogenerated holes.So a moderate amount of V in the supported catalyst may lead an increased the photocatalytic activity.