【作者】 卢鑫；

【导师】 王新军；

【作者基本信息】 河南师范大学 ， 无机化学， 2012， 硕士

【摘要】 二氧化钛是一种优良的光催化剂，具有广泛的应用前景。它具有光催化活性高、化学性质稳定、无毒和低成本等优势。但是，由于其禁带宽度较大（Eg=3.2eV），只能在紫外光区才能表现出光催化活性，而在这部分仅占太阳光的3-5%，加上其电子空穴复合率高的缺点，限制了二氧化钛对光能的有效利用。因此，为了制备高活性的TiO₂光催化材料，本文开展了以下几方面的研究工作。主要内容如下：1、为寻找到使用更简便、更绿色的方法来制备二氧化钛光催化材料，用三种不同的制备方法（溶胶凝胶法、反相微乳液法、生物模板法）制备出了TiO₂样品，通过XRD、SEM对合成的TiO₂样品的物相和结构进行了表征，以降解罗丹明B溶液的程度为参考对三种TiO₂样品的光催化性能作出对比，结合三种制备方法的反应时间、成本、毒性等相关因素，最后综合分析了三种制备方法的利与弊。2、为了提高二氧化钛的光催化活性，使用非金属B和P对TiO₂进行掺杂，采用溶胶凝胶法制备出了B-TiO₂和P-TiO₂样品，经过XRD表征发现，非金属掺杂后的TiO₂样品均有锐钛矿型，都具有降解染料溶液的能力，但是通过对比研究，发现掺杂B的改性效果要比掺杂P好，随后详细研究讨论了B掺杂TiO₂的制备以及影响催化效果的因素，以对染料溶液罗丹明B的降解程度为参考，研究了其光催化性能，最后在煅烧温度，B原子掺杂量，染料溶液PH值，催化剂投入量等方面确立了B掺杂的最优值，结论为500℃煅烧2h之后掺杂量为2%的B-TiO₂具有的光催化性能最好。3、为了进一步系统研究掺杂对TiO₂的改性效果，利用共掺杂的改性方法，共掺杂为比较少见的稀土元素和非金属元素的组合，采用溶胶凝胶法制备了单掺B、P及Gd-B共掺杂的TiO₂光催化剂，在对样品表征后，发现共掺杂之后，TiO₂的表面形貌发生了巨大变化，在保持锐钛矿相的前提下，晶粒尺寸减小，以致比表面积变大。以降解三种不同的染料溶液（活性艳蓝KGR、活性艳红X3B、活性艳红K2G）为参考，对比考察了它们光催化性能的高低，并进一步探讨了稀土元素Gd和非金属B掺杂提高光催化活性的机理。实验证明了稀土元素Gd和非金属B共掺杂可以减小TiO₂晶粒尺寸，有利于抑制光生电子-空穴对的复合，从而提高TiO₂光催化活性。研究结果可以得出结论稀土金属Gd和非金属B共掺杂的TiO₂的光催化活性要大于单掺杂的TiO₂和未掺杂的TiO₂。更多还原

【Abstract】 Titanium dioxide is a great photocatalytic material. It has good application prospect. It has manyadvantages such as high photocatalytic activity, chemical stability, non-toxic and low cost. But, its practicalapplication is limited in the UV region because of its large band gap value of3.2eV and low quantumyields, so TiO₂can only capture about3-5%of the solar irradiance at the earth’s surface. Therefore, inorder to improve the photocatalytic activity of TiO₂, this paper carried out research work including thefollowing several aspects. The main contents are the following:1, In order to find a method which is more simple and environmental for the preparation of titaniumdioxide material, three different kinds of preparation methods are used. They are sol-gel method, inversemicroemulsion method and biological template method. The prepared catalysts were characterized byX-ray diffraction, scanning electron microscope, and UV–Vis spectra.The photocatalytic activity of thethree different samples was evaluated through the photodegradation of Rhodamine B under UV light. Andthen the best method was found.2, In order to improve the photocatalytic activity of TiO₂, boron doped TiO₂and phosphorus dopedTiO₂nanoparticles were prepared using a sol–gel method. By contrast, boron doped TiO₂has smallercrystallite size and higher photocatalytic activity than that of phosphorus doped TiO₂samples and undopedTiO₂. And then different dosage of boron doping TiO₂were prepared, The photocatalytic activity of thesamples was evaluated by the photodegradation of Rhodamine B, and then research the relation aboutphotocatalytic performance and calcined temperature, boron doping amounts, PH, the quantity of catalystFinaly the best boron doping condition was found.3, In order to further research the modification effect on doping TiO₂, Gadolinium–boron codoped andmono-doped TiO₂nanoparticles were prepared using a sol–gel method, and tested for photocatalyticactivity by the UV light after a further calcination process. For comparison, a pure TiO₂sample was alsoprepared and tested under the same conditions. The prepared catalysts were characterized by X-raydiffraction, scanning electron microscope, and UV–Vis spectra. The photocatalytic activity of the samples was evaluated through the photodegradation of three different dyes under UV light. The experimentsdemonstrated that the gadolinium–boron codoped TiO₂（Gd–B–TiO₂） sample calcined at500℃possessedthe best photocatalytic activity, and the photodegradation rate of the Reactive Brilliant Red K2G aqueoussolution could reach to95.7%under UV irradiation for80min. The results showed that Gd–B–TiO₂hassmaller crystallite size and higher photocatalytic activity than that of mono-doped TiO₂samples andundoped TiO₂.更多还原