摘要
V-doped TiO2/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 TiO2 of 1.5%.The band edges in UV-vis spectra of the V-doped TiO2/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 V2O5 and so the mechanism of the degradation was changed.Electrons that transferred to the conductive band of V2O5 may be excited by irradiation to the conductive band of TiO2 and be captured by O2.However,they may also be transferred to the valence band of TiO2 and recombine with photogenerated holes.So a moderate amount of V in the supported catalyst may lead an increased the photocatalytic activity.
V - doped TiO2/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 mille phase and anatase phase are formed. The supported catalyst showed the highest photocatalytic activity at the mass fraction of V in TiO2 of 1.5%. The band edges in UV - vis spectra of the V - doped TiO2/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 V2O5 and so the mechanism of the degradation was changed. Electrons that transferred to the conductive band of V2O5 may be excited by irradiation to the conductive band of TiO2 and be captured by O2. However,they may also be transferred to the valence band of TiO2 and recombine with photogenerated holes. So a moderate amount of V in the supported catalyst may lead an increased the photocatalytic activity.
出处
《化学研究与应用》
CAS
CSCD
北大核心
2006年第6期703-707,共5页
Chemical Research and Application
基金
新疆大学应用化学研究所资助项目
昌吉学院科研基金资助项目
