纳米二氧化钛的制备及其性质研究

【作者】 王传彩；

【导师】 景志红；

【作者基本信息】 曲阜师范大学 ， 无机化学， 2010， 硕士

【摘要】 纳米科学与技术是20世纪和21世纪高科技,纳米科学对其他科学,产业以及社会的发展、进步有着举足轻重的地位。纳米产品已经创造了很大的社会效益和经济效益,纳米技术和纳米科学将会产生又一次工业革命,这也必将是我们人类科学技术发展史上的又一座划时代的里程碑。纳米二氧化钛材料是非常重要的无机材料。纳米TiO2作为光催化剂,具有安全、无毒副作用、性能稳定、成本低廉、无二次污染等优点,因此,纳米TiO2光催化中被得到广泛的应用。但是,也因其自身的空穴-电子对较容易复合以及对太阳利用率低的缺点,使TiO2的催化活性受到一些限制,因此为了克服TiO2本身的缺点来提高其光催化能力和催化活性是本论文的研究内容。可以通过使用多种手段对二氧化钛进行改性,比如：掺杂贵金属的修饰、非金属元素的掺杂、过渡金属元素的掺杂、表面处理等等。本论文主要通过掺杂金属银和钯来提高二氧化钛的催化活性。光催化活性实验结果表明,掺杂银和钯的TiO2比纯的TiO2有更高的催化活性,最佳掺杂量确定为3%。1.用溶胶-凝胶法制备了TiO2纳米粉体,并用5M的NaOH溶液对样品进行了处理,用XRD、HRTEM、TEM、FT-IR等手段对样品进行了表征。2.以钛酸四丁酯和硝酸银为原料,用溶胶-凝胶法、溶胶-凝胶法-水热法制备掺杂不同含量Ag的TiO2的纳米粉体,用FT-IR、SEM、XRD等手段对样品进行了表征,结果表明：掺杂银和未掺杂的TiO2纳米粉体均为四方相锐钛矿型,平均粒径大约为6～9 nm。适量银的掺杂有效抑制了粒径的增大以及向金红石型的相转化。通过降解刚果红、次亚甲基蓝、甲基橙和罗兰明-B染料,来研究所制备样品的光催化活性；用大肠杆菌、金黄色葡萄球菌和枯草杆菌进行抑菌性实验；用八通道微量仪,测定了大肠杆菌的生长代谢过程中的热功率-时间曲线,计算出生长速率常数,并确定了生长速率常数与样品的抑菌浓度的关系,最终确定了最佳抑菌浓度；实验结果表明：掺杂的TiO2比纯的TiO2活性都高,而且掺杂n(Ag-TiO2)=3%(摩尔比)的光催化活性和抑菌性都是最高的,说明适量的掺杂能有效的提高样品的催化活性。3.以钛酸四丁酯和氯化钯为原料,用溶胶-凝胶法制备掺杂不同含量Pd的二氧化钛纳米粉体,实验结果得出表明：掺杂后的TiO2催化活性和抑菌性比纯的二氧化钛粉体都有明显提高,其最佳的掺杂量为n(Pd-TiO2)=3%(摩尔比)。4.用水热法将TiO2纳米粉体转化为TiO2纳米管,用HRTEM、TEM、FT-IR、XRD等手段对样品进行了表征,通过TEM可知：纳米管顶端为针状。通过抑菌性实验表明：TiO2纳米管比TiO2纳米粉体的抑菌活性要低。最后,对本论文做了简单总结以及对纳米技术的未来发展进行了展望。更多还原

【Abstract】 Nano science and technology is advanced technology in the 20th and 21th century, and nanoscience enjoys a vital position in the development and progress of other sciences, industry and society. Nanoproducts have created remarkable social and economic returns. Nano science and technology will make the industrial revolution again, which be a new landmark in the distory of development of mankind’s technology. Nano titanium dioxide material is very important inorganic material. Nano titanium dioxide is a catalyst. Due to its safety, nonpoisonous side effect, excellent performance, low cost, no secondary pollution,et al, Nano titanium dioxide has been found wide application in the photocatalysis. But photocatalytic activity of Nano titanium dioxide has been restricted,because of electron-hole pair compositing very much and its low utilization for the sun. Overcoming weaknesses of nano titanium dioxide and improving its photocatalytic activity is the sum total content of thesis. Nano titanium dioxide modification by many ways,such as:doped-noble metals; doped-non-metallic elements; doped-transition metals; surface treatment and so on. The thesis improves mainly photocatalytic activity of nano titanium dioxide by doping-Ag and doping-Pd. The photocatalytic activity was tested with congo red dye as the objective decomposition matter. The experiments showed that the TiO2 nanoparticles doped with silver present higher photocatalytic activity than that of pure TiO2, and the optimum molar fraction of Ag in Ag-TiO2 is 3%. Primary Contents of the thesis are as follows:Firstly, pure TiO2 has been prepared by the sol-gel process,and the pure TiO2 is been treated by 5 M NaOH. It has been characterized by XRD, FT-IR, HRTEM and SEM techniques, respectively.Secondly, TiO2 nanoparticles with various amounts of silver have been prepared by the sol-gel process, and Ag in Ag-TiO2 is 3% preparing by sol-gel hydrothermal using tetrabutyl titanate and silver nitrate as raw materials. They have been characterized by XRD, SEM, HRTEMand FT-IR techniques, respectively. XRD results showed that both the pure TiO2 and Ag-TiO2 nanoparticles were tetragonal anatase phase and the average particle size is in the range of 6～9 nm. It would inhibit the increase of the crystallite size and the phase transformation from the anatase to rutile after TiO2 nanoparticles were doped with the appropriate silver. The photocatalytic activity was tested with congo red dye, Methylene blue, Rhodamine-B and Methyl orange, as the objective decomposition matter which was studied photocatalytic activity of the products; antibacterial experiments were carried on Escherichia coli, Staphylococcus aureus and Bacillus subtilis; by the TAM Air system, the thermal power-time curves of growth and metabolism of the colibacillus determined, the growth rate constant obtained, the relationship between the inhibitory concentration and the growth rate constant ensured, then optimal concentration obtained. The experiments showed that the TiO2 nanoparticles doped with silver present higher photocatalytic activity and bacteria restreint than that of pure TiO2, and the optimum molar fraction of Ag in Ag-TiO2 is 3%. The experiments showed that TiO2 nanoparticles could improve effectively photocatalytic activity after doping with the appropriate silver.Thirdly, TiO2 nanoparticles with various amounts of palladium have been prepared by the sol-gel process using tetrabutyl titanate and palladium The experiments showed that the TiO2 nanoparticles doped with palladium present higher photocatalytic activity and bacteria restreint than that of pure TiO2, and the optimum molar fraction of Pd in Pd-TiO2 is 3%, which are in agreement with the literatures.Fourthly, TiO2 nanotube had been prepared by the hydrothermal process, and had been characterized by HRTEM, TEM, XRD, and FT-IR techniques, respectively. TEM results showed that the tip of TiO2 nanotube was needle-like.The antibacterial experiments showd that TiO2 nanotube had lower antibacterial activity than TiO2 nanoparticles.At last, it gave a brief summary of this thesis and the outlook of nanotechnology future development.更多还原