The Study Of Preparation And Charac-Terization Of Nano-SnO₂and Compound Nanomaterials TiO₂/SnO₂

TiO₂is one of the most promising environmental friendly photocatalyst.Presently, the main subject of improving the photocatalytic activity of TiO₂is to expand the range of light absorption and improve its quantumefficiency. The modification of TiO₂with other semiconductor whoseconduction and valence band matches with TiO₂, such as SnO₂, canimprove the quantum efficiency.In this paper, the morphology and structure of nano SnO₂andTiO₂/SnO₂composite oxide prepared by sol-hydrothermal crystallizationmethod were characterized by XRD、SEM and TEM. Furthermore, theheterogeneous nucleation of TiO₂was also studied. The photocatalyticactivity of TiO₂/SnO₂prepared with different concentration of TNB wasmeasured by the photocatalytic oxidation of toluene.The acetone was used as the dispersant for preparation nano SnO₂with optimum morphology and dispersity. The spherical SnO₂particleswith1-2μm was synthesized by0.2mol acetone, reacting withK2SnO3·3H2O at150℃for16h. Moreover, the SnO₂particle would be more smooth and uniform after being calcined at400℃for2h.Taking the preparation of nano SnO₂as a sample, the roles of acetonein the preparation was investigated. The conclusion is that the truedispersant was the adamantanediol which formed in the process ofhydrothermal reaction due to the present of acetone. And then, theadamantanediol was used as dispersant and the nano SnO₂with the samemorphology、dispersity and particle size as that prepared with acetone wassuccessfully prepared.The TiO₂/SnO₂photocatalyst was prepared by sol-hydrothermalcrystallization method. The influence on the TiO₂heterogeneous nucleationby mixing the SnO₂particle was also studied. The result shows thataddition of SnO₂could reduce the crystal nucleus formation energy. Inaddition, more and more irregular TiO₂grain aggregated on the surface ofSnO₂sphere with the TNB concentration increasing. The TiO₂/SnO₂composite oxide with the best photocatalytic activity was prepared whenthe concentration of TNB increased to50times as the critical nuclearconcentration, and the degradation rate of toluene improved42.72%compared with commercial TiO₂P25.