复合TiO2纳米管催化剂的制备及其可见光分解水制氢的特性-化学工程与技术专业论文.docxVIP

上海交 上海交通大学硕士论文 II II 化剂（CdS 占催化剂总质量的 1.96%，wt%）的制氢速率最高，为 12.90μmol/(h·g)。综合 XRD 和 XPS 的结果分析，有可能是在微波的作 用下，CdS 与 TiO2 形成了某种化合物或是 CdS 与 TiO2 相互作用，使得 其催化活性增强。 用共沉淀法制备了不同含量 Fe 掺杂的 TiO2 纳米颗粒（Fe-TiO2NP）。 利用此纳米颗粒，用微波法合成了相应的 Fe 掺杂的 TiO2 纳米管催化剂 （Fe-TiO2NT）。UV-Vis 图谱表明，相比于纯 TiO2 纳米管，Fe-TiO2NT 向可见光区红移，而且红移量随着掺铁比例增加而递增。但异常的是 2%Fe-TiO2NT（Fe 原子和 Ti 原子的摩尔比为 2:100，下同）的红移量比 其他催化剂红移量都要大。从 XRD 的结果分析，2%Fe-TiO2NT 催化剂 的晶型最为完好，为纯金红石型。而其他比例的 Fe-TiO2NT 催化剂的晶 型都是锐钛型的二氧化钛和钛酸钠盐的混晶。光催化制氢实验表明，在 可见光照射下，Fe-TiO2NT 催化剂都没有产氢活性。而在全波段照射条 件下，Fe-TiO2NT 催化剂都有活性，并且催化活性随着掺铁量的增大而 提升。但是与纯 TiO2 纳米管相比，它们的催化活性有所降低。通过 XPS 的结果分析认为，Fe3+部分取代了 TiO2 晶格内的的 Ti4+，成为了光生电 子和空穴复合的中心，降低了电子和空穴的寿命，也减小了光生电子被 传递至催化剂表面进行反应的几率。 关键词：制氢 光催化 二氧化钛纳米管 微波法 铁 硫化镉 III III PREPARATION OF MODIFIED TIO2 NANOTUBE CATALYST AND ITS PHOTOCATALYTIC ACTIVITY OF HYDREGEN EVOLUTION FROM WATER SPLITTING UNDER VISIBLE LIGHT Abstract Procedures and optimized conditions were studied by microwave irradiation method for preparation of TiO2 nanotube. Based on this method, a series of CdS-TiO2 nanotube and Fe-TiO2 nanotube with different CdS or Fe content were synthesized. Their photocalytical activity was also evaluated by hydrogen production from water splitting. The crystal phase and structure were characterized by the modern techniques such as UV-Vis, TEM, XRD and XPS. The connection between catalysts structure and their photocatalytic activity was also investigated. The dissertation contents are mainly as follows: TiO2 nanotube was synthesized by microwave irradiation method. TEM images showed that the optimal craftworks of TiO2 nanotubes were synthesized when the microwave power was 300w and that the irradiation time is 120 min. The diameter of nanotube was about 5~10nm and its length PAGE PAGE VI were from 150nm to 200nm. CdS-TiO2 nanotube (CdS-TiO2NT) catalyst was synthesized on the basis of the microwave irradiation method. The CdS-TiO2NT showed good quality nanotube form. Through UV-Vis, visible light absorbance of CdS-TiO2NT was fewer than CdS