| Metal oxide semiconductor material have become one of the mostly used photocatalysts due to its nontoxic,easy preparation and low cost and so on.However,the disadvantages such as high recombination rate of photogenerated carriers and low quantum efficiency existed in pure metal oxide material,limited their practical applications.Researchers have found that coupling TiO2 with other metal oxides can highly enhance the photocatalytic activity.This is attributed to the formation of heterojunction between TiO2 and other semiconductors creating new photochemical and photophysical performances which do not exist in the single semiconductor and thus achieving better charge separation in a light energy conversion system.In this thesis,we successfully prepared TiO2 and TiO2-ZrO2 composite with hybrid structure,which was further characterized using SEM,XRD,UV-vis and BET analysis.Methyl blue solution was chosen as degradation target to evaluate the photocatalytic activity of TiO2-ZrO2 composite.The detailed preparation of this novel phase photocatalysts can be carried out as following:(1)TiO2 microspheres were prepared by hydrothermal reaction and calcinations treatment using PMMA microspheres as the template.Under the best conditions,the as-prepared TiO2 microspheres with the average size of ca.1 μm were in terms of regular spherical shape and have anatase phase.We found that the degradation rate of MB solution reached 96.9%under high pressure mercury light irradiation for 30 min.(2)The TiO2-ZrO2 hybrid composite microspheres were prepared by templating and hydrothermal reaction method under 160℃ for 10 h,in which PMMA microspheres were used as template.The as-prepared composite have good UV responsive photocatalytic activity.The coupling of TiO2 with ZrO2 decreased the particle size of TiO2 nanoparticles,and increased the specific surface area.Under UV light irradiation,MB solution with the concentration of 10 mg/L can be degraded 99.8%in 30 min. |
