【作者】 张翠轩；

【导师】 陈汝芬；

【作者基本信息】 河北师范大学 ， 无机化学， 2008， 硕士

【摘要】 二氧化钛（TiO₂）是一种重要的无机功能材料,具有许多独特的物理化学性质,广泛应用于废水废气净化的催化剂、涂料、陶瓷、抗菌剂等领域。由于TiO₂粉体在光催化过程中易失活、易团聚、难回收等,使其在应用中受到一定限制,而负载型TiO₂薄膜的制备可避免这些弊端。本文采用溶胶-凝胶法及自组装技术,分别以廉价的四氯化钛（TiCl₄）、硫酸氧钛（TiOSO₄）为原料,以SiO₂球、普通载玻片为载体进行了TiO₂/SiO₂、TiO₂/glass复合材料的制备;进行了聚乙二醇（PEG）、离子掺杂及酸处理改性研究;研究了表面活性剂对TiO₂粒子形貌和粒径的调控规律;并对样品的光催化性能等进行了探讨。本文的主要研究内容包括:1.以TiCl4为原料,SiO₂球为载体,制备了纳米TiO₂/SiO₂薄膜,研究了不同聚合度的PEG、Fe³⁺掺杂及PEG2000和Fe³⁺共掺杂对样品的影响。结果表明:以8mmol/L的十二烷基硫酸钠（SDS）为自组装介质、采用水浴80℃制胶和组装可得到粒径均匀且量多的TiO₂;随着PEG含量增加,薄膜的孔密度、孔径逐渐增大且更加均匀;PEG含量过高、组装次数过多、PEG聚合度过大时,TiO₂薄膜均易出现裂缝。PEG2000掺杂时,得到锐钛矿与金红石的混晶;锐钛矿相对含量随PEG2000浓度的增大而提高。光催化实验表明:添加PEG时,光催化性能有所提高,PEG600、PEG2000、PEG20000的光催化最佳浓度分别为12.0%、2.0%和0.10%;PEG2000掺杂时组装二次光催化性最佳;Fe³⁺掺杂能提高光催化效果,Fe³⁺最佳浓度为0.00125%;PEG2000与Fe³⁺离子共掺杂时,光催化性能高于任一单独掺杂。2.以TiOSO₄为原料,SiO₂球为载体,研究了TiOSO₄-H₂O-乙二醇（C2H6O₂）体系中制备TiO₂/SiO₂薄膜的条件,并进行了Cu2+掺杂、硫酸（H2SO4）改性及其光催化性能研究。该体系制备TiO₂/SiO₂的最佳条件为:TiOSO₄（1.07mol/L）、乙二醇、H2O体积比为2:3:3;80℃水浴制胶30min;80℃水浴组装2h;随水浴陈化12h;550℃热处理2.5h。与以TiCl4为原料相比,该法制得的纳米TiO₂粒径更加细小,锐钛矿相含量相对较高。未掺杂时,550℃热处理所得样品的光催化效果最好;Cu²⁺掺杂能提高光催化效果,最佳浓度为0.10%,组装三次光催化性最佳;TiO₂薄膜经H₂SO₄处理后光催化效果也得到提高。3.以TiCl₄为原料,普通载玻片为载体制备TiO₂/glass薄膜,研究了非离子表面活性剂PEG2000和阴离子表面活性剂十二烷基苯磺酸钠（SDBS）对TiO₂的形貌、粒径、结构的影响及其光催化性能。PEG2000和SDBS均能调控TiO₂粒子的形貌和粒径。添加PEG2000时,热处理环境和PEG2000的浓度对TiO₂粒子的表面形貌都有影响,密闭条件下热处理时,随PEG2000浓度的增加,TiO₂粒子逐渐由棒状变为球状;通空气条件下热处理时,TiO₂粒子由不规状逐渐变为规则的卵石状,且通空气条件得到TiO₂的粒径较大。添加SDBS水浴条件制备时,随SDBS浓度的增加,TiO₂粒子逐渐由棒状变为球状,最终又变为棒状,当SDBS浓度为2.0%时,TiO₂薄膜呈现为直径约3um的圆环相互连结构成的网状;超声条件制备时,TiO₂粒子为类虫状。无论添加PEG2000还是SDBS,随其浓度的增加,所得TiO₂粒子的粒径均先减小后增大。XRD的研究表明,随PEG2000浓度的增加,金红石相对含量逐渐提高;随SDBS浓度的增加,锐钛矿相对含量逐渐提高,且当SDBS浓度为40.0%时,为纯锐钛矿相。光催化实验发现:添加PEG2000和SDBS后均能提高样品的光催化效果,且最佳浓度分别为9.8%和8.0%。更多还原

【Abstract】 As an important inorganic functional material, Titania （TiO₂） has many unique physical and chemical properties. This material is extensively used as a catalyst in purification of air and water, a pigment in making paints, an enamel, an antimicrobial and so on. TiO₂ powders are usually restricted by some performances in the application because they are easier to become inactive, to reunite and harder to be reclaimed in the photocatalytic process. But TiO₂ films can avoid these disadvantages.The aim of this thesis is to obtain TiO₂ /SiO₂ or TiO₂/glass films through combining the sol-gel technology and the layer-by-layer self-assembly method by using low-cost Titanium chloride （TiCl₄） or Titanyl sulfate （TiOSO₄） as the raw material and SiO₂ beads or glass slides as the raw carriers. In this research we have studied the modification to the composite with polyethylene glycol （PEG）, ions and acids, the control disciplinarians of surfactants to the shape and size of TiO₂, photocatalysis of the samples etc..The major work includes the following aspects:1. TiO₂/SiO₂ films are prepared by using TiCl4 and SiO₂ beads as the raw material and carriers respectively. The effect of PEG with different polymerization degree, Fe³⁺, polyethylene glycol 2000 （PEG2000） and Fe³⁺ doped together to the samples are studied.The results show that TiO₂ with uniform size and a large number can be obtained by using Sodium dodecyl sulphate （SDS） as the self-assembly medium, preparing sol and synthesizing in water bath at 80℃. The density and diameter of the holes become bigger and more uniform gradually with the increasing concentration of PEG. TiO₂ films are easier to split open when the concentration of PEG is too high, or the synthesis circle and polymerization degree of PEG are too much. The mixed phases of anatase and rutile can be obtained when PEG2000 is doped and the relative content of anatase increases with the increasing concentration of PEG2000. Photocatalytic experiments show that photocatalytic activity increases by doping PEG and the optimal concentration of PEG600, PEG2000 and PEG20000 are 12.0%, 2.0% and 0.10% respectively. And the optimal synthesis circle is two when PEG2000 is doped. Photocatalysis can be increased by doping Fe³⁺ and the optimal concentration is 0.00125%. And photocatalytic activity is higher by doping PEG2000 and Fe³⁺ together compared to doping separately.2. Preparation conditions of TiO₂/SiO₂ films in the system of TiOSO₄-H₂O-CH₆O₂ by using TiOSO₄ and SiO₂ beads as the raw material and carriers, modifying with Cu²⁺ or sulfuric acid （H₂SO₄） and photocatalysis are studied.The optimal preparation conditions of TiO₂/SiO₂ in this system are that the cubage ratio of TiOSO₄ （1.07 mol/L）, C₂H₆O₂ and H2O is 2:3:3, preparing sol and synthesizing are in water bath at 80℃for 30min and 2h respectively, aging time in water bath is 12h and annealing time at 550℃is 2.5h. Compared to TiCl₄, TiO₂ with smaller size and higher relative content of anatase can be obtained by this method. Photocatalytic activity is the best when the samples undoped are annealed at 550℃. By doping Cu²⁺, photocatalytic activity increases and the optimal concentration is 0.10%. And the optimal synthesis circle is three. After treating with H₂SO₄, photocatalytic activity of TiO₂ also increases.3. TiO₂/glass films are prepared by using TiCl4 and glass slides as the raw material and carriers. The effect of nonionic surfactant PEG2000 and anionic surfactant Sodium dodecyl benzene sulfonate （SDBS） to the shape, size and structure of TiO₂ and photocatalysis are studied.PEG2000 and SDBS can both control the shape and size of TiO₂ particles. Annealing ambient and the concentration of PEG2000 can affect the shape of TiO₂ when PEG2000 is doped. After annealing in airtight ambient the shape of TiO₂ particle varieties from rod-like to sphere-like, whereas it varieties from irregular to egg-like in air ambient with the increasing concentration of PEG2000. And the size of TiO₂ obtained from air ambient is bigger. By doping SDBS and preparing in water bath, the shape of TiO₂ particle transforms from rod-like to sphere-like and again to rod-like with the increasing concentration of SDBS. And TiO₂ film arranges like a web consisting of some circles whose diameters are about 3um averagely when the concentration is 2.0 %. But the shape of TiO₂ is worm-like by preparing in ultrasonic ambient. After doping PEG2000 or SDBS, the size of TiO₂ becomes smaller at first and bigger afterward with the increasing concentrations of them. XRD patterns show that the relative content of rutile increases with the increasing concentration of PEG2000 and the relative content of anatase increases with the increasing concentration of SDBS. And pure anatase can be obtained when SDBS added is 40.0%. In photocatalytic experiments it can be concluded that PEG2000 and SDBS can both improve photocatalysis of the samples and the optimal concentration are 9.8% and 8.0% respectively.更多还原