HMST-5A/SnCl4 complex catalyst is prepared by using MST-5A and SnCl4 in alcohol solution as a medium,and characterized by DTA,IR and UV-vis spectrum.The preparation method is simple and the catalyst is easily separated.The experimental results show that the catalyst has high activity on the esterification of n-butyl alcohol and acetic acid and can be used repeatedly.
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.
