【作者】 谢立进；

【导师】 马峻峰；

【作者基本信息】 中国海洋大学 ， 应用化学， 2006， 硕士

【摘要】 环境污染和能源短缺是当今社会面临的两大问题,如何有效地解决这两大问题是众多科学工作者努力工作的方向。在众多的半导体光催化剂材料中,TiO₂以其强氧化性、光诱导超亲水性、无毒性和长期稳定性在净化环境方面表现出重要的应用前景。然而,TiO₂光催化材料因其光生电子-空穴对复合几率较高,禁带宽度较大等不利条件严重阻碍了其在光催化氧化技术领域中的推广应用。近年来,为了解决这个问题,有不少研究者提出Bi₂InNbO₇、Bi₄Ti₃O₁₂、Bi₂Ti₂O₇、Bi₁₂TiO₂₀、Bi₂WO₆和BiVO₄等含Bi的金属复合氧化物可作为具有可见光响应的新型光催化剂。然而,其中一些复合氧化物的制备方法因其本身固有缺陷严重影响了它们的光催化性能。因此,为了制备高活性的光催化材料,本文开展了以下几个方面的研究工作。1.以硝酸铋（Bi（NO₃）₃·5H₂O）和钛酸丁酯（Ti（OC₄H₉）₄）为原料,以氢氧化钾（KOH）为矿化剂,通过控制矿化剂浓度、反应温度和反应时间等条件等,采用水热方法首次制备出纯度高,结晶发育良好,分散性好,无团聚、大小为10μm Bi₁₂TiO₂₀正四面体微单晶,其最佳工艺条件为:[KOH]=4.5mol/L,反应温度为180℃,反应时间为4h。为得到Bi₁₂TiO₂₀纳米尺寸粉体,本论文中提出一种新颖的制备方法-异丙醇辅助水热法。采用硝酸铋（Bi（NO₃）₃·5H₂O）和硫酸钛Ti（SO₄）₂为原料,在反应温度为140℃,反应时间为1h,异丙醇浓度为20vol%的条件下,制备出了大小约为10nm并具有良好结晶度的Bi₁₂TiO₂₀纳米晶粉体,从而实现了Bi₁₂TiO₂₀纳米晶粉体的低温合成;UV-Vis分析结果显示,所合成的粉体在紫外光区和可见光区均具有较好的光吸收性能。2.以OP（聚乙烯醇壬基苯酚醚）为乳化剂,环己烷为油相,正丁醇为助剂,硝酸铋（Bi（NO₃）₃·5H₂O）和硫酸钛Ti（SO₄）₂为原料,采用反相微乳法成功地合成出Bi₄Ti₃O₁₂纳米晶粉体;并利用X-ray衍射（XRD）、透射电镜（TEM）、红外光谱（FT-IR）和紫外-可见分光光谱（UV-Vis）等分析技术对制备的样品进行了表征。结果显示,与传统共沉淀法所合成的粉体相比,此方法所合成的粉体颗粒不仅尺寸较小,约为35nm,而且形状规则,粒径分布均匀,在可见光区也具有较好的光吸收性能。3.以硝酸铋（Bi（NO₃）₃·5H₂O）和钨酸钠（Na₂WO₄·2H₂O）为原料,以硝酸锂（LiNO₃）和硝酸纳（NaNO3）的混合物为反应介质,混合比为27:23（重量比）,采用低温熔盐法成更多还原

【Abstract】 Environmental pollution and the shortage of energy sources are the most serious problems among recent environmental issues in the world. Many investigations have been focused on how to solve the two problems. Titania as an oxide semiconductor photocatalyst appears to take on a promising and important prospect in environmental purification due to its strong oxidizing power, photoinduced hydrophilicity, nontoxicity and long-term photostability. However, its large band gap and fast recombination rate of photogenerated electron/hole pairs hinder the commercialization of this technology in a certain extent. Recently, many compounds contained Bi ion have been well known as new photocatalysts, which could be used in a visible light region, such as Bi₂InNbO₇、Bi₄Ti₃O₁₂、Bi₂Ti₂O₇、Bi₁₂TiO₂₀、Bi₂WO₆ and BiVO₄. Nevertheless, there are still such inherent limitations as reduced photocatalysts’activity due to high synthesizing temperature and other shortcomings in the preparation process of photocatalysts. Therefore, this thesis, based on new ideas in synthesizing process, mainly focuses on the following research works to prepare highly active photocatalytic materials contained Bi ion:1. Bi₁₂TiO₂₀ regular tetrahedron single crystals were successfully synthesized by a simple hydrothermal process for the first time with using Ti（OC₄H₉）₄ and Bi（NO₃）₃·5H₂O as raw materials, KOH as mineralizers and by adjusting the KOH concentration, reaction time and temperature. The powders obtained are of good quality such as high purity, high degree of crystallinity and well-controlled morphology. Their average particle size is about 10μm. The optimal processing condition: [KOH]=4.5M, reaction temperature is 180℃and reaction time 4h.Nearly spherical Bi₁₂TiO₂₀ nanocrystals were synthesized at 140oC for 1h via a novel isopropanol–assisted hydrothermal method with using Bi（NO₃）₃·5H₂O and Ti（SO₄）₂ as reactants and introducing 20vol% of isopropanol. The resultant powders with a good crystallinity were about 10 nm in size. Their UV-Vis absorption spectra revealed that the更多还原