Preparation Of TiO₂Nanomaterial And Its Photocatalytic Properties

TiO2nanomaterials have become a class of important functional materials formany emerging research fields, especially environmental remediation, solar energyconversion, and solar fuel production. There are many of the TiO2preparationmethods, in this article, the TiO2materials were made by a chemical corrosion method.Meanwhile, the surface morphology and crystal structure of our products werecontrolled by adding different kinds of anion. What’s more, the photocatalyticproperties of our TiO2were improved by halogen element doped method.In this article a kind of anatase TiO2with porous hexagonal prism structure wasfabricated by a thermal decomposition of (NH4)0.3TiO1.1F2.1precursor. The(NH4)0.3TiO1.1F2.1precursor was synthesized by a simple chemical method usingTi-Cu amorphous alloy and NaF as reactants in the HNO3solution. The formationprocess of the products, the formation reasons of the hexagonal prism structure andthe variations of crystal structure of our produts were investigated by SEM, HR-TEM,XRD and FTIR. The experiment shows that (NH4)0.3TiO1.1F2.1precursor withhexagonal prism structure was synthesized in the reaction system when theconcentration of NaF that adding in the system was0.1mol/L, and the anatase TiO2with porous hexagonal prism structure was got by a thermal treatment of precursor at5500C for1h. The photocatalytic activity of as-prepared TiO2was evaluated througha study of the decomposition of RhB under the light irradiated from a Xe lamp.Anatase TiO2with porous hexagonal prism structure showed the highestphotocatalytic activity that the10ml RhB solution with the concentration of10mg/Lwas decomposed in100min.In this article, the properties of rutile TiO2with soaking process or dopingprocess were also investigated. The variations of the morphology and crystal structureof samples with or without modification were investigated by SEM, XRD, EDS. Theexperiment shows that the products of Ti-Cu alloy in65wt.%of HNO3reactionsystem were rutile TiO2with layered nanoflower structure. And after soaking ordoping process. The crystal of the TiO2kept the same, grain size was changed, thegranularity of products after doping process became thinner than it after soakingprocess. After soaking process, the photocatalytic activity of TiO2improved slightly,but not obvious. However, the photocatalytic activity increased significantly afterdoping treatment. By using NaBr with different concentration doped the TiO2, we find that the more NaBr concentration, the greater fine grain granularity was, and with thebetter photocatalytic activity.