Study On The Photocatalytic Activity And Preparation Of TiO₂ With {001} Facets Modified By AgX And Composites

Semiconductor materials have been applied in the catalysis and electrodes field.Titanium dioxide with non-toxic,stability and easy of operation characters have become the most potential applications as a photocatalyst.In this study,TiO₂ nanosheets with {001}facets were synthesised by a hydrothermal method.The tetrabutyl titanate was used as titanium source and HF were used as the morphology control agents.The obtained TiO₂ photocatalyst had more than 69.3%{001} facets due to the existence of HF,and the catalytic activity was also improved.A series of composite samples were prepared by photo-deposition method,chemical deposition-coprecipitation method and ion exchange method including M-TiO₂?M=Ag,Au,Pt?,AgX-TiO₂,Ag@AgX-TiO₂?X=Cl,Br,I?,AgI/Ag-TiO₂,AgI/AgX-TiO₂?X=Cl,Br?,Ag@AgI/AgX-TiO₂?X=Cl,Br?,AgI/Ag@AgX-TiO₂?X=Cl,Br?.A series of characterization methods such as XRD,UV-Vis DRS,etc were used to characterize the structure,crystalline form,elemental analysis of these prepared samples.A lot of research focused on the photocatalytic active of these composite photocatalysts in visible light.In this paper,photocatalytic degradation of RhB?15 mg/L?was used as probe to evaluate the catalytic properties and some possible photocatalysis mechanism were given.The plasmonic effects of metal nanoparticles played a great role in M-TiO₂?M=Ag,Au,Pt?photocatalysts.Significantly,the optimum deposited quantity of noble metals were 0.5%?Ag?,0.1%?Au?and 0.5%?Pt?,respectively.The order was AgI-TiO₂>AgBr-TiO₂>AgCl-TiO₂ for the properties of photocatalysts,which was due to the different width of forbidden band and anions species.Among,AgBr-TiO₂ had bad catalytic performance in degrading RhB dilute solutions.AgO played a great role in improving stability of catalyst and catalytic activity in Ag@AgX-TiO₂?X=Cl,Br,I?photocatalysts.As Cl-photocatalyst and Br-photocatalyst,AgI/Ag@AgCl-TiO₂ and AgI/AgBr-TiO₂ showed the greatest catalytic performance.A new photo-deposition method was used in this study,and it was helpful for improving the photocatalytic activity of modified photocatalysts.