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TiO_2具有高效、廉价、无毒及光化学稳定性好等优点,因而被广泛应用于光能转化和利用领域,如太阳能电池、光催化分解水制氢和环境污染物降解等.但是,TiO_2仍然存在一些缺陷制约了其应用,其中,最关键的问题是光生电荷分离效率低.因此,人们对其进行了掺杂、异质结构建和Z型结构建等来解决这一问题,其中Z型结近年来备受关注.全固体Z型结的构建目前主要有两种方式:PSI-C-PSII和PSI-PSII.前者PSI与PSII间要插入中间导电层(如Au、rGO等)来实现界面欧姆接触;后者则无中间层,而是基于界面设计来实现欧姆接触.本文以构建PSI-PSII Z型结为目标,以TiO_2和WO_3为基础半导体材料,采用原位溶剂热生长的方法构建WO_3量子点/TiO_2结构,借助氢气还原反应在界面处引入氧缺陷.采用透射电子显微镜、X射线衍射和拉曼光谱研究了复合晶体结构,采用X射线光电子能谱、紫外可见光谱和荧光光谱等手段研究了Z型结的界面结构和能带结构.结合光催化分解水产氢活性来建立Z型结结构与光催化性能的关联关系.表征结果表明,在TiO_2上进行原位溶剂热成核反应可点缀WO_3量子点,并且量子点粒径随W前驱体用量的增加而变大.两种半导体材料为TiO_2锐钛矿和WO_3晶体结构,且WO_3的XRD特征峰和Raman特征吸收峰会随W前驱体用量增加而变大.通过对WO_3/TiO_2进行氢气还原处理,使其表面形成大量W~(5+)和氧缺陷,一方面提高了催化剂对可见光的吸收,另一方面在界面形成欧姆接触,实现了Z型结构的构建.Z型结构实现了光催化分解水产氢反应,其中WTH10光催化活性最好.本文为新型Z型光催化剂的设计和构建提供了新思路和策略.
TiO_2 is widely used in the field of light energy conversion and utilization, such as solar cells, photocatalytic decomposition of water to hydrogen and the degradation of environmental pollutants because of its high efficiency, low cost, non-toxicity and good photochemical stability. However, TiO_2 still exists Some defects restrict its application, among which the most critical problem is the low efficiency of photo-induced charge separation, therefore, it has been doped, heterostructure and Z-type structure to solve this problem, etc., in which the Z-junction At present, there are mainly two ways to construct all-solid Z-junction: PSI-C-PSII and PSI-PSII. The former should be inserted into the middle conductive layer (such as Au and rGO) between PSI and PSII But the latter is based on the interface design to achieve ohmic contact.This paper aims to build the PSI-PSII Z-junction, TiO_2 and WO_3-based semiconductor materials, using in situ solvent thermal growth method to build WO_3 quantum dots / TiO_2 structure, oxygen deficiency was introduced at the interface by hydrogen reduction reaction.The structure of the composite crystal was studied by transmission electron microscopy, X-ray diffraction and Raman spectroscopy. X-ray photoelectron spectroscopy, UV-Vis spectrum Fluorescence spectroscopy and other means to study the Z-junction structure and band structure.The combination of photocatalytic decomposition of aquatic hydrogen activity to establish the relationship between the Z-junction structure and photocatalytic performance.The characterization results show that the TiO 2 in situ solvent heating The nucleation reaction can be dotted with WO_3 quantum dots, and the size of quantum dots becomes larger with the increase of the amount of W. The two kinds of semiconductor materials are anatase TiO_2 and WO_3 crystal structure, and the XRD and Raman peaks of WO_3 W precursor increased with the increase.Wu_3 / TiO_2 by hydrogen reduction treatment to a large number of its surface W 5 (+) and oxygen defects, on the one hand to improve the catalyst for visible light absorption, on the other hand the formation of the interface Ohmic contact to achieve the Z-type structure.Z-type structure to achieve the photocatalytic degradation of aquatic hydrogen reaction, WTH10 photocatalytic activity of the best.This paper for the new Z-type photocatalyst design and construction provides a new idea and strategy.