Titanium Dioxide Nanomaterials Preparation And Its Application In Oilfield

The semiconductor metal oxides have the special energy band structures, thus they posses uniquechemical and physical properties, especially in photochemical field in which they show an attractiveapplication prospect. TiO₂as a typical semiconductor oxide, which the band gap is3.2eV, is able to realizephotocatalytic reaction under ultraviolet light. So TiO₂has been the focus of material research, which theseresearches lie mainly in synthesizing special structure and morphology of TiO₂nano materials by the newpreparation method, or expanding the available light response and inhibition of photo-generated electronand hole recombination through the doping to change the energy level structure of TiO₂, to improvephotocatalytic performance of TiO₂nanomaterials. Herein, TiO₂nanomaterials were synthesized by anodicoxidation technique, hydrothermal method, and electrochemical deposition ways, meanwhile, the physicalproperties of TiO₂nanomaterials were proved through a series of characteristic methods and the mechanismof preparation was explored. The effects of the TiO₂nanomaterials were also investigated in oilfield watertreatment.1. According to experimental data,“induced electric field induced” theoretical model of the anodicoxidation of TiO₂nanotubes is put forward: TiO₂semiconductor properties and inducting the presence ofthe measured electric field is the mainly controlling factors on forming tube-type structure; Chemicaldissolution is decision factors of TiO₂nanotubes uniform distribution in the initial stage of anodizingoxidation; The produced cyclic structure of TiO₂nanotubes outer wall with oxidation time is related toapplied oxidation voltage and the region space of TiO₂between nanotubes and nanotubes. The crystallinestate, morphology and specific surface area of TiO₂nanotubesand are related to heat treatment temperature.2. The metals can be deposited in TiO₂nanometer arrays by the electrochemical deposition method,and depositing four metal elements on the surface of TiO₂nano arrays are discussed. In same experimentalconditions, the metals’ existence state depend on the nature of the metal element itself, and the depositionform of the metal element is different to impact the TiO₂crystal change; After heat-treatment, Fe, Co andNi can change into corresponding oxide, and then the composite oxide of TiO₂-based nanomaterials areformed, while Ag in before and after heat-treatment are only Ag/TiO₂composite, and the correspondingphysical properties before and after the heat-treatment have relevant changes.3. Ag loaded TiO₂nanotube materials can be obtained by the direct hydrothermal and photocatalyticreaction, moreover, Ag loaded pathways of two kinds of methods are different. In the hydrothermal reaction,Ag as compound form is adsorpted on TiO₂nanotubes surface and wrapped in TiO₂nanotubes. In the latterpart of the heat treatment process, Ag as simple substance with TiO₂nanotubes form composite; Ag loadedTiO₂nanotube materials were obtained by photocatalytic reaction under the ultraviolet irradiation, and Ag+ions were reduced to the Ag particles to adsorb in the surface of TiO₂nanotubes. The Ag presence of TiO₂nanotubes had no effect for their electronic spectra, Ag nanoparticles loaded TiO₂nanotube is not basedon extended TiO₂nanotubes light absorption range to achieve, but loading Ag nanoparticles in TiO₂nanotubes surface become photoproduction electronic capture center to realize photoproduction electronand light born hole effective separation, and further increase the TiO₂nanotubes photocatalytic activity. 4. TiO₂nanomaterials on the adsorption of metal ions, which include the three fundamental forces,van der waals forces, chemical bonding, hydrogen bonding action, and electrostatic attraction, TiO₂nanomaterials adsorption is usually the comprehensive results of several forces. Comparing adsorptioncapacity of three kinds of TiO₂nanomaterials for oilfield waste water Pb²⁺, Hg+and As²⁺, shows that theadsorption capacity of TiO₂nanoparticles is strongest, that of TiO₂nanotubes is the second, and that ofTiO₂nanowires is the weakest in the same adsorption conditions.5. Based on the photocatalytic degradation of simulated oilfield containing sewage effect combinedwith quantitative calculation, to explore the principle of photocatalytic degradation of polyacrylamide.Because of the chemical bond strength decided to the stability of the chemical bond, three types ofpolyacrylamides in the solution determines the final photocatalytic degradation pathway, and only in theform of intramolecular crosslinking to produce acrylic intermediate degradation products.6. PS microspheres as templates, Cu/TiO₂hollow microspheres were successfully prepared,comparing with the IR, SEM, TEM results of Cu/TiO₂before and after doped the copper, prove thatsynthesized TiO₂microspheres are hollow structures; the different charge of PS microspheres and TiO₂surface is key factors on preparation of Cu/TiO₂shell structure; In the Cu/TiO₂hollow microspheres ofdopping0.75%copper have higher catalytic activity.