Study On The Preparation Of Supported Nanocomposite Photocatalyst And Its Application

Recently, because nano TiO2are of such good performance as chemical stability, high photocatalysis, low cost, no poison and so on. It has been applied to organic compound decomposition, sewage treatment and air purifi-cation broadly. TiO2has become a research hotspot in material field. But how to develop its function effectively has also been a key step to ensure photo-catalysis in good progress and to promote for industries. At present, Relative researches have madesome progress, the reason is most organic pollutants in aqueous and gaseous state can be oxided or reduced into innoxious minerals without the secondary pollutants, so the photocatalytic technology is becoming green purifying environment technology.Recently titanium dioxide has been extensively studied as a photocatalyst. According to the coprecipitation method and sol-gel method, the supported nanocomposite photocatalyst Fe2O3-TiO2/AC with high temperature treatment were synthesized. The preparation and application technology were both studied in the paper. Its photocatalytic activity on the degradation of acrylic acid with a high concentration of30000mg·L-1under visible light irradiation was studied. The results indicate:active carbon as carrier Fe2O3doping of 0.05～0.1%, TiO2duty rate with25%、calcination temperature500～600℃. pH1-2of the solution, the catalyst shows the best photocatalysis activity. And the degradation of acrylic acid wastewater can reach up to94.5%under UV-light. The photocatalyst structure was tested by XRD and UV-VIS, the characterization results prove the presence of TiO2in the form of anatase, and Fe2O3were well-dispersed inside the body of TiO2particles in the form of small clusters rather than independent crystalline phase located at the surface of the crystal particles. And also Fe2O3doping can dramatically broaden the photoresponse range so that increase visible light absorption intensity of the photocatalyst.SO4-is used for the surface modification of Fe2O3-TiO2/AC,and according to this method solid superacid SO42-Fe2O3-TiO2/AC is fabricated. Photocatalysis activity of catalyst is observed in this paper. The result indicate: the concentration of sulfuric acid soaking、usage of catalyst and pH value of the solution will influence the photocatalysis effect. In the best condition, the degradation rate of high concentration of acrylic acid industrial wastewater can reach up to99.7%, and the value of COD decrease from30000mg·L-1to90mg·L-1, which meet the standard of country industrial wastewater discharge. The photocatalyst acidic property and structure were tested by XRD and FT-IR, characterization results show that:SO42-modification is beneficial to enhance crystallinity of the TiO2anatase. And SO42-absorbed on the surface of TiO2in the form of coordination, both B acid and L acid center exit in the catalyst so that inhibit the recombination of electron and holes, which improve the photocatalysis activity. The success of the present study should shed a light on the feasible application of acrylic acid in the waste water treatment.