中文摘要：

高效TiO2基光催化材料的开发一直是催化领域的研究热点,主要的策略是如何有效地分离光生载流子.制备多晶相的TiO2材料可引入异质/相结结构使电子与空穴朝不同方向移动,从而避免电子与空穴复合;另外,在TiO2中掺杂其他金属或非金属也可以有效地降低电子与空穴的复合率,掺杂的元素作为电子捕获阱俘获光生电子,以实现电子空穴的有效分离.近些年,作为一种全新的掺杂剂,氧空穴可以有效改善TiO2的光催化活性,所制TiO2具有可见光的全光谱吸收能力,因此该类TiO2呈现出黑色.通过上述方法均可以制备出高活性TiO2基光催化材料,如果能够将这些方法耦合一起,则可能制备出活性更高的光催化剂.因此,本文将异相结结构和空穴掺杂耦合起来,用多孔钛酸盐衍生物在H2中高温焙烧制得一种全新的黑色TiO2（B）/锐钛矿双晶TiO2–x纳米纤维.不同于其他TiO2基光催化材料,该样品仅由Ti和O元素组成,通过Ti和O元素的组合,形成了双晶结构和空穴掺杂两种特殊的结构,借助场发射（FESEM）、拉曼光谱（Raman）、氮气物理吸脱附、X射线光电子能谱（XPS）、热重（TG）、紫外可见漫反射光谱（UV-Vis）和荧光光谱（PL）等表征分析了样品的结构及其光催化性能间构效关系.FESEM结果显示,黑色TiO2（B）/锐钛矿双晶TiO2–x为长1–5mm、宽0.2mm的纤维结构,Raman结果表明,锐钛矿相在特征波段（140 cm–1左右）和TiO2（B）的特征波段（220–260 cm–1）均发生蓝移,说明该两相中均存在氧空穴;该样表面未检测到Ti3＋,因此氧空穴可能分散在TiO2（B）和锐钛矿相的体相中.根据黑色TiO2（B）/锐钛矿双晶TiO2–x和白色TiO2（B）/锐钛矿双晶TiO2的失重差,估算出前者的O/Ti原子比为1.97.光催化降解甲基橙实验结果显示,黑色TiO2（B）/锐钛矿双晶TiO2–x的光催化活性是白色双晶TiO2的4.2倍,锐钛矿TiO2的10.5倍,且连

英文摘要：

Black TiO2（B）/anatase bicrystalline TiO2-x nanofibers were synthesized from a porous titanate derivative by calcination in H2, and were characterized using field-emission scanning electron microscopy, Raman spectroscopy, N2 adsorption-desorption analysis, X-ray photoelectron spectroscopy, thermogravimetric analysis, ultraviolet-visible diffuse reflection spectroscopy and photoluminescence measurements. Characterization results showed that no Ti3＋ was present on the surface of black bicrystalline TiO2-x and oxygen vacancies were distributed in the bulk of both TiO2（B） and anatase phases. The O/Ti atom stoichiometric ratio of black bicrystalline TiO2-x was estimated to be 1.97 from the difference of mass loss between black bicrystalline TiO2-x and white bicrystalline TiO2 without oxygen vacancies. The photocatalytic activity of black bicrystalline TiO2-x was 4.2 times higher than that of white bicrystalline TiO2 and 10.5 times higher than that of anatase TiOz. The high photocatalytic activity of black bicrystalline TiO2-x was attributed to its effective separation of electrons and holes, which may be related to the effects of both bicrystalline structure and oxygen vacancies. Black bicrystalline TiO2-x also exhibited good photocatalytic activity after recycling ten times. The black bicrystalline TiO2-x nanofibers show potential for use in environmental and energy applications.