Tio < Sub > 2 < / Sub > The Preparation And Performance Characterization Of Nano Light Catalyst

Double strut precipitation method were applied to prepare nano-TiO2powder, and influence of sort and concentration of precipitant, substrate solution, pH, and calcinations temperature and time on crystal structure and property of TiO2powder were studied. Ag-TiO2was prepared by surface precipitation method, and effects of Ag doping concentration and precipitator concentration on microstructure and photocatalysis were investigated. The technology, production process and parameter of preparation nano-TiO2material via precipitation were optimized, and theory and experiment foundation were supplied.1. TiO2powder with smaller particle size and less impurity was acquired using NH4HCO3as precipitant; TiO2powder with larger particle size and more impurity was obtained precipitated by NH3·H2O; nano-TiO2powder prepared by NaOH presented high crystallinity and small particle size, and the lower concentration of precipitant was, the higher crystallinity will be.2. Sample showed high crystallinity, small particle size and less impurity, due to proper pH. As the ratio of substrate and precursor solution increased, the crystallinity and particle size of samples increased; while the ratio was too large, particle size decreased. Adding (NH4)2SO4into substrate solution, crystallinity and growth of particle would be inhibited.3. As the calcination temperature increased, crystallinity and particle size increased, specific area and porosity decreased; when calcination temperature increased to800℃, part of anatase changed into rutile. Calcination time also showed no-effect on crystal structure.4. With increment of Ag concentration, the diffraction peak of Ag-TiO2nano-powder boarded, and diffraction intensity decreased, indicated that part of Ag particle had entered into crystal lattice of anatase. Diffraction peak boarded and intensity decreased with the increase of precipitant concentration, indicating that precipitation of Ag was promoted by the increasing of precipitant concentration. 5. The smaller particle size, larger the special area, higher crystallinity and less impurty were, the higher the photocatalysis property would be. Adopting proper condition, nano-TiO2powder with excellent photocatalysis performance would be obtained. Adopting Proper amount of Ag, photocatalysis performance of Ag-TiO2could be significantly improved. However, excessive addition of Ag, the photocatalysis property would be worsen.