Study On Nano Fe₂O₃and Ag₂O About Improving The Photocatalytic Activity Of TiO₂and Its Mechanism

Nanoparticle TiO₂is intensively applicated in solar cell solar battery,antibiosis, hydrogen production, photocatalytic activity and other fields due toits chemical stability, natural abundance, low cost, notoxicity, and lowenvironment impact. However, the large band gap of TiO₂（about3.0³.4eV）can only absorb ultraviolet light with a wavelength less than400nm, which isonly5%of the sunlight, making the sunlight utilization rate is very low. Theecombination rate of photogenerated electron hole pair stimulated by TiO₂ishigh and the life is short, which limite TiO₂in the field of photocatalysis.Therefore, in order to improve the photocatalytic performance of TiO₂,thispaper is to study TiO₂photocatalytic properties of semiconductor nanocomposite. The specific contents are shown as follows:（1） Use butyl titanate as titanium source and concentrated hydrochloricacid as the inhibitor, adjust the reaction time, prepare TiO₂nanorod arrays byhydrothermal method. And on this basis, TiO₂is prepared by a micro filmthrough the addition of HF.（2） Using FeCl₃-6H₂O as raw material, urea as precipitating agent,isopropyl alcohol as the solvent, Fe2O3nano particles are prepared byhydrothermal method, which studys the influence of reaction time, addition ofFe2O3nano particle morphology. The Fe2O3nanoparticles are supported onTiO₂nanorod arrays to get the Fe₂O₃/TiO₂heterojunction compositematerials;Through the test of the microstructure characterization and photocatalytic performance, its results show that: the modified Fe₂O₃nanoparticles can significantly improve the photocatalytic activity of TiO₂under visible light. Fe₂O₃/TiO₂photocatalytic enhancement mechanism isinvestigatd based on the experimental results.（3） Use AgNO₃and NaOH as raw materials, PVP as dispersant,to prepareAg2O nanoparticles by ultrasonic precipitation method. The influence ofNaOH and Ag₂O addition on the microstructure of PVP nanoparticles wasdiscussed. The Ag2O nanoparticles are supported on TiO₂nanorod arrays toget the Ag₂O/TiO₂heterojunction composite materials;Through the test of themicrostructure characterization and photocatalytic performance, its resultsshow that: modified Ag₂O nanoparticles can significantly improve thephotocatalytic activity of TiO₂under visible light.In addition, the Ag₂O/TiO₂heterojunction photocatalytic reaction wasfound in the course of the experiment. Ag₂O produced from the decompositionof Ag elements, the formation of three yuan Ag/Ag₂O/TiO₂composite system,the composite system can further improve the photocatalytic activity of TiO₂.The decomposition of Ag₂O can produce Ag, which formed stable three yuanAg/Ag₂O/TiO₂composite system. The composite system can further improvethe photocatalytic activity of TiO₂.