The Research Of TiO₂ Nanoparicles Couple With Silver Halide And Its Immobilization

Titanium dioxide as a kind of important broadband gap oxide semiconductor material,is widely used in environmental governance,photoelectric conversion,antibacterial,photocatalysis and many other fields.However,some drawbacks such as low efficiency of absorption of visible light and difficult for recovering,limit the engineering application of TiO₂.Therefore,it's important to improve the visible light absorption of TiO₂.This article mainly included the following aspects:?1?M-TiO₂ was synthesized using tetrabutyl titanate as titanium source,and P123,PVP,F127,and chitosan-CTAB as template by hydrothermal method.The products were tested by XRD,SEM,TEM,uv-vis spectra and BET,the results showed that:M-TiO₂ synthesized by F127 was the best,its specific surface area reached 241.86 m²/g,pore size distribution was concentrated in the 3.788 nm.The degradation of rhodamine B?RhB?reached 60.1%under ultraviolet light irradiation for 60 min.?2?TiO₂ nanosheets?TiO₂-NSs?were prepared with a hydrothermal method at 150?using strong alkali liquor as the solvent.The morphology and structure were tested by XRD,TEM,and UV-vis absorption spectra.The results showed that the one which was synthesized by 10 M NaOH solution and calcinated at 400?was the best.Compared with P25,its degradation for RhB reached 7.5%after 120 min's visible light irradiation which was 2 times as high as that of P25.?3?Ag/AgX/TiO₂ composite photocatalytic materials were prepared with a impregnation method using the optimized M-TiO₂ and TiO₂-NSs.The morphology and structure were tested by XRD,HRTEM,UV-vis absorption spectra and XPS.The results showed that AgBr and AgCl are finely dispersed on the surface of M-TiO₂ and TiO₂-NSs.Particularly,Ag/AgBr/TiO₂-NSs?30%?performed the best catalytic property that its degradation of RhB reached 50.1%after 60 min's visible light irradiation.For compound M-TiO₂ and TiO₂-NSs,the catalytic efficiency improved by more than 15 times.?4?In order to recycle the photocatalytic materials and overcome secondary pollution,we immobilized the powder materials.In this paper,we used PVP-PVA and sodium alginate as the carrier to synthesis the PVP-PVA?PP?series and sodium alginate?SA?series monolithic photocatalysts.The morphology and structure were tested by SEM,FT-IR and BET.The results showed that powdered composite photocatalytic materials could disperse in the PP or SA carrier uniformly.Photocatalytic activity tests showed that the SA series was about 4 times active than PP series about 4 times.Under visible light,the degradation for RhB of SA12-Ag/AgBr/TiO₂-NSs which loaded 12%of Ag/AgBr/TiO₂-NSs reached 51.6%after 120 min's visible light irradiation.What's more,after five times recycled experiment,its remains more than 96%of the activity.This results laid a good foundation for engineering applications of TiO₂.