二氧化钛纳米材料的多元敏化及其应用研究
发布时间：2018-11-02 18:45
【摘要】：在众多半导体纳米材料中，二氧化钛（TiO2）由于耐腐蚀、环境友好、生物相容、光催化活性高且易于制备、价格低廉等优点，在诸多应用领域吸引了持续的关注，比如太阳能电池/光电化学池，光催化降解污染物、生物传感及药物传输等。这些应用研究不但要利用TiO2的自身特性更多地还要考虑多种功能化修饰及其与应用环境的相互作用，主要原因是其自身带隙较大只能吸收紫外区的太阳光谱，，而且单一的TiO2纳米材料也不能够满足广泛的实际需求。因而实现TiO2的各种功能修饰，对改善与提高材料性能，拓宽材料应用领域不仅具有重要的理论意义，更有重要的实际应用价值。对于纳米材料而言，除去不同材料间的性能差异，同种材料在形貌与结构上的差异也会引起材料性能的较大改变。同时，不同的研究领域对材料的形貌与结构需求也不尽相同。因而，对纳米材料形貌结构的控制研究也尤为重要。基于此，本文从敏化剂的组分设计、形貌控制及结构优化等方面入手，系统研究了基于纳米TiO2的复合材料的性能以及其在光谱分析、光催化产氢及有机污染物去除等领域的应用。主要研究内容如下： （1）TiO2纳米材料制备：分别采用阳极氧化法和水热法在钛箔上制备了分布均匀、排列有序的一维TiO2纳米管和纳米线阵列（第2章）；通过调节水热法相关技术参数，在钛箔表面制备了具有特殊结构的TiO2纳米材料，包括纳米树叶、纳米花、纳米线/纳米树叶阵列、纳米线/纳米花阵列、纳米花/纳米树叶阵列；讨论了水热法技术条件下TiO2纳米结构的形成机理（第3章）。 （2）TiO2纳米管金属纳米粒子敏化：结合光催化沉积技术，以TiO2纳米管为结构模板，在其管内沉积金纳米颗粒；利用沉积在TiO2纳米管内表面的金纳米颗粒构建了一个局域三维电磁场，对限域于管内的目标分子产生表面增强拉曼信号；实现了环境中多环芳烃的表面增强拉曼光谱分析（第4章）。 （3）TiO2纳米管的金属及金属氧化物纳米粒子敏化：结合电沉积与热氧化技术在TiO2纳米管上制备出垂直生长的单晶CuO纳米线阵列；证实了现有CuO纳米线生长机理模型：压力引起的晶界扩散和压力产生与释放机理共同调节CuO纳米线生长；通过纳米线生长过程技术参数调节得到了CuO纳米蘑菇和纳米片结构；证实了维系CuO纳米线生长的离子迁移通道，并成功解释了该迁移通道对CuO纳米线直径和长度的调控；通过光催化沉积技术成功地将银纳米粒子负载于上层CuO纳米线与下层TiO2纳米管上，并将该材料应用于环境污染物的监测及消除，实现了双功能化循环利用（第5章）。 （4）TiO2纳米管的II-VI组半导体纳米晶敏化：结合水热法与连续离子层吸附与反应技术在双官能团分子的帮助下获得了II-型核壳CdTe/CdS量子点并将其成功地负载于TiO2纳米管阵列电极上；在II-型核壳结构敏化剂内，电子和空穴波函数可以有效地分离并产生高寿命的载流子分离态最终可以显著地提升复合材料的光电响应性能，壳层CdS对CdTe核的包被可以有效地降低CdTe因光刻蚀而引起的不稳定性。所得复合电极展现了良好的产氢效能。 （5）TiO2纳米管的I-III-VI2组半导体纳米晶敏化：不同于基于镉和铅的II-VI族及IV-VI族二元半导体纳米晶，I-III-VI2族半导体纳米晶兼具高光电响应性（整个可见及近红外区）与环境友好性，是极具潜力的下一代敏化剂。其中，CuInSe2纳米晶的性能最为优异，然而受限于三元纳米晶自身生长的复杂性及现有合成方法的不足，CuInSe2纳米晶的可控性制备仍然很难达到。我们通过控制溶胶合成技术参数，获得了单分散粒径可控的实心/中空CuInSe2纳米晶及量子点；探讨了实心小粒径纳米晶的形成机理及纳米晶从实心到中空的演变机理；用单分散中空及实心CuInSe2纳米晶分别敏化TiO2纳米管，证实了中空CuInSe2纳米晶拥有更高的光催化特性（第7章）；将中空CuInSe2纳米晶修饰于TiO2纳米管，开展了光催化产氢的研究；通过对该电极的多重修饰构建了基于TiO2纳米管的准量子阱结构，该结构有效的提高了复合光电极中载流子的分离及传输效率；通过循环伏安分析及阻抗谱分析，研究了电极内部载流子的传输路径及传输（复合）阻力，并以开路电压在切断光源后的衰减曲线及荧光光谱对结果进行了佐证（第8章）。
[Abstract]:In a plurality of semiconductor nano materials, titanium dioxide (TiO2) has the advantages of corrosion resistance, environmental protection, bio-compatibility, high photocatalytic activity, easy preparation, low cost and the like, Photocatalytic degradation of pollutants, biological sensing and drug delivery. These applications will not only take advantage of the self-properties of TiO2, but also consider the interaction with the application environment. The main reason is that its own band gap can only absorb the solar spectrum of the ultraviolet region. and the single TiO2 nano material can not meet the wide practical requirement. thus realizing various functional modifications of TiO2, improving and improving the performance of the material, widening the application field of the material not only has important theoretical significance, but also has important practical application value. In the case of nano materials, the difference of properties between different materials is removed, and the difference in morphology and structure of the same material can also cause a great change in material properties. At the same time, different research fields have different shapes and structural needs of materials. Therefore, it is very important to control the morphology of nano-materials. Based on this, the properties of nano-TiO _ 2-based composites and their applications in spectral analysis, photocatalytic hydrogen production and organic pollutant removal are systematically studied in this paper from the aspects of component design, morphology control and structure optimization of sensitizer. The main contents of the study are as follows: (1) preparation of TiO2 nano material: uniformly distributed and ordered one-dimensional TiO2 nanotube and nanowire array (chapter 2) are prepared on the titanium foil by adopting an anodic oxidation method and a hydrothermal method respectively (chapter 2); and the related technology of the water thermal method is adjusted. Parameters: TiO2 nanomaterials with special structures are prepared on the surface of the titanium foil, including nano-leaf, nano-flower, nano-wire/ nano-leaf array, nano-wire/ nano-flower array, nano-flower/ nano-leaf The formation mechanism of TiO _ 2 nanostructures under the technical conditions of hydrothermal method is discussed in this paper. (2) TiO2 nanotube metal nano-particle sensitization: combined with photocatalysis deposition technology, TiO2 nanotube is used as a structure template, gold nanoparticles are deposited in the tube, a local area is constructed by using gold nanoparticles deposited on the inner surface of the TiO2 nanotube, A three-dimensional electromagnetic field is used for generating a surface-enhanced Raman signal on the target molecules in the tube, and the surface-enhanced Raman spectrum analysis of the polycyclic aromatic hydrocarbon in the environment is realized. (4). (3) Sensitization of metal and metal oxide nanoparticles of TiO2 nanotubes: a single crystal CuO nanowire array grown vertically on TiO2 nanotubes in combination with electrodeposition and thermal oxidation; confirmed existing CuO nano-tubes; The mechanism model of rice line growth: the diffusion of grain boundary caused by pressure and the mechanism of pressure generation and release co-regulate the growth of CuO nanowires; the structure of CuO nano-mushroom and nano-sheet was obtained by adjusting the technical parameters of the growth process of nanowires; and confirmed the retention of CuO nanowires. The long ion migration channel successfully explains the regulation of the diameter and length of CuO nanowires by the migration channel, and successfully loads the silver nanoparticles on the upper CuO nanowires and the lower TiO2 nanotubes through the photocatalytic deposition technique, and the material is applied to environmental pollution. The dye is monitored and eliminated, and the dual-functional follow-up is realized. Ring utilization (Chapter 5). (4) TiO _ 2 nanotube II-VI group semiconductor nanocrystal sensitization: combined with water thermal method and continuous ion layer adsorption and reaction technology to obtain II-type nuclear shell CdTe/ CdS quantum dots with the help of bifunctional molecules and successfully load it in T in that i-type nuclear shell structure sensitizer, the electron and hole wave function can effectively separate and produce high-life carrier separation state, The photoelectric response property of the composite material and the coating of the shell layer CdS on the CdTe nucleus can effectively reduce the CdTe cause. The instability caused by light etching. The resulting composite electricity Very good hydrogen-producing efficiency is shown. (5) I-III-VI2 group of TiO2 nanotubes are sensitized: different from Group II-VI and IV-VI binary semiconductor nanocrystals based on Pb and lead, I-III-VI2 semiconductor nanocrystals have high photoelectric responsivity (whole visible and near-infrared region) and environment-friendly. The properties of CuInSe2 nanocrystals are the most excellent. However, CuInSe2 nanocrystals have the most excellent properties, but are limited by the complexity of the growth of ternary nanocrystals and the shortage of existing methods of synthesis. CuInSe2 By controlling the synthesis parameters of sol, solid/ hollow CuInSe2 nanocrystals and quantum dots with controllable monodispersed particle size were obtained by controlling the synthesis parameters of sol. The mechanism of formation of solid small particle size nanocrystals was discussed. The evolution mechanism of nano-crystals from solid to hollow was studied by using monodisperse hollow and solid CuInSe2 nanocrystals to sensitize TiO2 nanotubes. It was confirmed that the hollow CuInSe2 nanocrystals had higher photocatalytic properties (Chapter 7); and the hollow CuInSe2 nanocrystals were modified to TiO2 nanotubes. In this paper, a quasi-quantum well structure based on TiO2 nanotubes is constructed by multi-modification of the electrode, which effectively improves the separation and transfer efficiency of carriers in the composite photoelectrode. Through cyclic voltammetry analysis and impedance spectrum analysis, the transmission path and transmission (recombination) resistance of carriers in the electrode are studied, and the attenuation curve and fluorescence light after cutting off the light source with open-circuit voltage are studied.
【学位授予单位】：湖南大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TB383.1;O614.411
本文编号：2306643
[Abstract]:In a plurality of semiconductor nano materials, titanium dioxide (TiO2) has the advantages of corrosion resistance, environmental protection, bio-compatibility, high photocatalytic activity, easy preparation, low cost and the like, Photocatalytic degradation of pollutants, biological sensing and drug delivery. These applications will not only take advantage of the self-properties of TiO2, but also consider the interaction with the application environment. The main reason is that its own band gap can only absorb the solar spectrum of the ultraviolet region. and the single TiO2 nano material can not meet the wide practical requirement. thus realizing various functional modifications of TiO2, improving and improving the performance of the material, widening the application field of the material not only has important theoretical significance, but also has important practical application value. In the case of nano materials, the difference of properties between different materials is removed, and the difference in morphology and structure of the same material can also cause a great change in material properties. At the same time, different research fields have different shapes and structural needs of materials. Therefore, it is very important to control the morphology of nano-materials. Based on this, the properties of nano-TiO _ 2-based composites and their applications in spectral analysis, photocatalytic hydrogen production and organic pollutant removal are systematically studied in this paper from the aspects of component design, morphology control and structure optimization of sensitizer. The main contents of the study are as follows: (1) preparation of TiO2 nano material: uniformly distributed and ordered one-dimensional TiO2 nanotube and nanowire array (chapter 2) are prepared on the titanium foil by adopting an anodic oxidation method and a hydrothermal method respectively (chapter 2); and the related technology of the water thermal method is adjusted. Parameters: TiO2 nanomaterials with special structures are prepared on the surface of the titanium foil, including nano-leaf, nano-flower, nano-wire/ nano-leaf array, nano-wire/ nano-flower array, nano-flower/ nano-leaf The formation mechanism of TiO _ 2 nanostructures under the technical conditions of hydrothermal method is discussed in this paper. (2) TiO2 nanotube metal nano-particle sensitization: combined with photocatalysis deposition technology, TiO2 nanotube is used as a structure template, gold nanoparticles are deposited in the tube, a local area is constructed by using gold nanoparticles deposited on the inner surface of the TiO2 nanotube, A three-dimensional electromagnetic field is used for generating a surface-enhanced Raman signal on the target molecules in the tube, and the surface-enhanced Raman spectrum analysis of the polycyclic aromatic hydrocarbon in the environment is realized. (4). (3) Sensitization of metal and metal oxide nanoparticles of TiO2 nanotubes: a single crystal CuO nanowire array grown vertically on TiO2 nanotubes in combination with electrodeposition and thermal oxidation; confirmed existing CuO nano-tubes; The mechanism model of rice line growth: the diffusion of grain boundary caused by pressure and the mechanism of pressure generation and release co-regulate the growth of CuO nanowires; the structure of CuO nano-mushroom and nano-sheet was obtained by adjusting the technical parameters of the growth process of nanowires; and confirmed the retention of CuO nanowires. The long ion migration channel successfully explains the regulation of the diameter and length of CuO nanowires by the migration channel, and successfully loads the silver nanoparticles on the upper CuO nanowires and the lower TiO2 nanotubes through the photocatalytic deposition technique, and the material is applied to environmental pollution. The dye is monitored and eliminated, and the dual-functional follow-up is realized. Ring utilization (Chapter 5). (4) TiO _ 2 nanotube II-VI group semiconductor nanocrystal sensitization: combined with water thermal method and continuous ion layer adsorption and reaction technology to obtain II-type nuclear shell CdTe/ CdS quantum dots with the help of bifunctional molecules and successfully load it in T in that i-type nuclear shell structure sensitizer, the electron and hole wave function can effectively separate and produce high-life carrier separation state, The photoelectric response property of the composite material and the coating of the shell layer CdS on the CdTe nucleus can effectively reduce the CdTe cause. The instability caused by light etching. The resulting composite electricity Very good hydrogen-producing efficiency is shown. (5) I-III-VI2 group of TiO2 nanotubes are sensitized: different from Group II-VI and IV-VI binary semiconductor nanocrystals based on Pb and lead, I-III-VI2 semiconductor nanocrystals have high photoelectric responsivity (whole visible and near-infrared region) and environment-friendly. The properties of CuInSe2 nanocrystals are the most excellent. However, CuInSe2 nanocrystals have the most excellent properties, but are limited by the complexity of the growth of ternary nanocrystals and the shortage of existing methods of synthesis. CuInSe2 By controlling the synthesis parameters of sol, solid/ hollow CuInSe2 nanocrystals and quantum dots with controllable monodispersed particle size were obtained by controlling the synthesis parameters of sol. The mechanism of formation of solid small particle size nanocrystals was discussed. The evolution mechanism of nano-crystals from solid to hollow was studied by using monodisperse hollow and solid CuInSe2 nanocrystals to sensitize TiO2 nanotubes. It was confirmed that the hollow CuInSe2 nanocrystals had higher photocatalytic properties (Chapter 7); and the hollow CuInSe2 nanocrystals were modified to TiO2 nanotubes. In this paper, a quasi-quantum well structure based on TiO2 nanotubes is constructed by multi-modification of the electrode, which effectively improves the separation and transfer efficiency of carriers in the composite photoelectrode. Through cyclic voltammetry analysis and impedance spectrum analysis, the transmission path and transmission (recombination) resistance of carriers in the electrode are studied, and the attenuation curve and fluorescence light after cutting off the light source with open-circuit voltage are studied.
【学位授予单位】：湖南大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TB383.1;O614.411
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