二氧化钛基纳米复合结构的制备及其光催化性能的研究
发布时间：2019-06-09 20:31
【摘要】：物理化学性质稳定,无毒,成本低等优势的存在,让纳米TiO_2半导体在光催化领域得到了很高的重视。作为众多光催化材料中的最有潜力的金属氧化物半导体,受到了世界上众多科研人员的青睐。但是不可否认,在实际操作过程当中仍然存在着一些不能回避的问题,比如只能被太阳光中的紫外光激发产生电子和空穴,受激发产生的电子-空穴对的复合几率较大等限制着TiO_2半导体光催化技术的进步。鉴于以上几点,本论文的工作主要是通过水热法制备TiO_2半导体材料为主,通过尺寸的调控,采用上下转换发光元素掺杂,以及与其他半导体进行复合等等,对TiO_2半导体材料进行改良研究,本篇论文的研究的主要工作包括以下几个方面:1.在FTO上,通过稀土元素Yb~(3+)和Er~(3+)的引入,通过水热法、溶胶-凝胶法等手段构建了新型的复合结构光催化剂TiO_2:Yb~(3+),Er~(3+)/TiO_2 NRAs/CdSe。其中TiO_2:Yb~(3+),Er~(3+)薄膜作为一个媒介,通过上转换过程,将近红外光转换为可见光;同时,一维结构的TiO_2纳米棒阵列具有较高的比表面积,阵列高度有序化,为光生电子的输运提供了快速通道。吸附在TiO_2纳米棒阵列表面的CdSe量子点能够拓宽催化剂的光响应范围,从紫外光区域延伸到可见光区域。复合结构光催化剂样品TiO_2:Yb~(3+),Er~(3+)/TiO_2 NRAs/CdSe在降解罗丹明B(RhB)方面,展现出较为出色的光催化性能。该复合结构不仅拓展了光催化剂的光吸收范围,同时也抑制了其电子-空穴对的复合,对光催化降解性能的提升起到了促进作用。2.为了改善纳米结构光催化剂的催化性能,我们以碳纤维布为基底,对生长在碳纤维上的纳米棒阵列进行稀土元素Eu~(3+)和Tb~(3+)的掺杂,设计了一种新型的复合光催化剂TiO_2-G/TiO_2 NRAs:Eu~(3+),Tb~(3+)/Cs2CO3/CdS。罗丹明B作为目标污染物用来测定样品TiO_2-G/TiO_2 NRAs:Eu~(3+),Tb~(3+)/Cs2CO3/CdS的光催化降解活性。研究发现,样品TiO_2-G/TiO_2 NRAs:Eu~(3+),Tb~(3+)/Cs2CO3/CdS展现出显著增强的光催化性能表现。样品的光催化活性如此明显的提升很大程度上是由于稀土离子Eu~(3+)和Tb~(3+)的存在能够被紫外光激发,产生了一个强度较高的可见光能够被CdS吸收,产生更多的光生载流子。此外,石墨烯和碳酸铯(Cs2CO3)在光催化反应过程中,在加速电子传输方面扮演了重要的角色。光催化剂生长在碳布上,有利于催化剂的回收和重复使用。3.有机钙钛矿材料作为高性能的光吸收层,能够吸收波长在350 nm~800 nm之间大部分的太阳光,利用碳纤维布为基底,设计制备了复合结构光催化剂TiO_2NRAs/CH3NH3PbI3/Cu2O。复合结构光催化剂TiO_2 NRAs/CH3NH3PbI3/Cu2O中Ti O_2 NRAs、CH3NH3PbI3、Cu2O三者之间的能带能够形成自下而上的能级差,有利于电子的转移;在氙灯的照射下,样品TiO_2 NRAs/CH3NH3Pb I3/Cu2O表现出出色的光催化降解活性。4.具有高比表面,良好导电性的的二维结构TiO_2纳米片阵列在光催化降解方面的应用还较为少见。特别是纳米片阵列生长在碳纤维布上,能够形成3D结构,去提高催化剂的比表面积。因此我们设计了异质结构的光催化剂TiO_2 NSAs/Cu2O。对制备的样品的形貌,结构和光催化降解性能进行了表征。
[Abstract]:The physical and chemical properties are stable, non-toxic, low in cost and the like, so that the nano-TiO _ 2 semiconductor is highly valued in the field of photocatalysis. As the most promising metal oxide semiconductor in many photocatalytic materials, it has been favored by many scientific researchers in the world. However, there are some problems that can't be avoided during the actual operation, such as the generation of electrons and holes only by the ultraviolet light in the sunlight, the recombination probability of the electron-hole pairs generated by the excitation is large, and the like, and the progress of the photocatalytic technology of the TiO _ 2 semiconductor is limited. In view of the above, the work of this thesis is mainly through the hydrothermal method to prepare the TiO _ 2 semiconductor material, by the control of the size, the up-and-down conversion of the light-emitting element doping, and the combination with other semiconductors, etc. to improve the TiO _ 2 semiconductor material. The main work of this thesis includes the following aspects:1. The novel composite photocatalyst TiO _ 2: Yb ~ (3 +), Er ~ (3 +)/ TiO _ 2NRAs/ CdSe was constructed by hydrothermal method, sol-gel method and the introduction of the rare-earth element Yb ~ (3 +) and Er ~ (3 +) on the FTO. The TiO _ 2: Yb ~ (3 +) and Er ~ (3 +) thin films are used as a medium, and the near-infrared light is converted into visible light by the up-conversion process. The CdSe quantum dots adsorbed on the surface of the TiO _ 2 nanorod array can broaden the light response range of the catalyst and extend from the ultraviolet light area to the visible light area. TiO _ 2: Yb ~ (3 +), Er ~ (3 +)/ TiO _ 2NRAs/ CdSe in the composite photocatalyst samples showed excellent photocatalytic performance in the degradation of rhodamine B (RhB). The composite structure not only expands the light absorption range of the photocatalyst, but also inhibits the recombination of the electron-hole pair, and plays a catalytic role in the improvement of the photocatalytic degradation performance. In order to improve the catalytic performance of the nano-structure photocatalyst, a novel composite photocatalyst TiO _ 2-G/ TiO _ 2 NRAs: Eu ~ (3 +), Tb ~ (3 +)/ Cs2CO3/ CdS was designed based on the carbon fiber cloth as the substrate and the doping of the rare-earth element Eu ~ (3 +) and Tb ~ (3 +) on the nanorod array grown on the carbon fiber. The photocatalytic degradation of TiO _ 2-G/ TiO _ 2 NRAs: Eu ~ (3 +), Tb ~ (3 +)/ Cs2CO _ 3/ CdS was determined as the target pollutant. It was found that TiO _ 2-G/ TiO _ 2NRAs: Eu ~ (3 +), Tb ~ (3 +)/ Cs2CO _ 3/ CdS exhibited significantly enhanced photocatalytic performance. The increase of the photocatalytic activity of the sample is largely due to the presence of the rare-earth ions Eu ~ (3 +) and Tb ~ (3 +), which can be excited by the ultraviolet light, and a higher intensity visible light can be absorbed by the CdS, resulting in more photo-generated carriers. In addition, the graphene and cesium carbonate (Cs2CO3) play an important role in accelerating the electron transport in the light-catalyzed reaction process. The photocatalyst is grown on the carbon cloth and is beneficial to the recovery and the reuse of the catalyst. As a high-performance light-absorbing layer, the organic perovskite material can absorb most of the sunlight with the wavelength between 350 nm and 800 nm, and the composite structure photocatalyst TiO _ 2 NRAs/ CH3NH3PbI3/ Cu2O is prepared by using the carbon fiber cloth as the substrate. The energy band between Ti O _ 2NRAs, CH3NH3PbI3 and Cu2O in the composite structure photocatalyst TiO _ 2NRAs/ CH3NH3PbI3/ Cu2O can form a bottom-up energy level difference, which is beneficial to the transfer of electrons; under the irradiation of a xenon lamp, the sample TiO2 NRAs/ CH3NH3Pb I3/ Cu2O shows excellent photocatalytic degradation activity. The application of the two-dimensional structure TiO _ 2 nanosheet array with high specific surface area and good electrical conductivity is rare in the photocatalytic degradation. In particular, that nano-sheet array is grown on the carbon fiber cloth, so that the 3D structure can be formed to improve the specific surface area of the catalyst. So we designed the heterogeneous structure of the photocatalyst TiO _ 2 NSAs/ Cu2O. The morphology, structure and photocatalytic degradation of the prepared sample were characterized.
【学位授予单位】：济南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36;O644.1
[Abstract]:The physical and chemical properties are stable, non-toxic, low in cost and the like, so that the nano-TiO _ 2 semiconductor is highly valued in the field of photocatalysis. As the most promising metal oxide semiconductor in many photocatalytic materials, it has been favored by many scientific researchers in the world. However, there are some problems that can't be avoided during the actual operation, such as the generation of electrons and holes only by the ultraviolet light in the sunlight, the recombination probability of the electron-hole pairs generated by the excitation is large, and the like, and the progress of the photocatalytic technology of the TiO _ 2 semiconductor is limited. In view of the above, the work of this thesis is mainly through the hydrothermal method to prepare the TiO _ 2 semiconductor material, by the control of the size, the up-and-down conversion of the light-emitting element doping, and the combination with other semiconductors, etc. to improve the TiO _ 2 semiconductor material. The main work of this thesis includes the following aspects:1. The novel composite photocatalyst TiO _ 2: Yb ~ (3 +), Er ~ (3 +)/ TiO _ 2NRAs/ CdSe was constructed by hydrothermal method, sol-gel method and the introduction of the rare-earth element Yb ~ (3 +) and Er ~ (3 +) on the FTO. The TiO _ 2: Yb ~ (3 +) and Er ~ (3 +) thin films are used as a medium, and the near-infrared light is converted into visible light by the up-conversion process. The CdSe quantum dots adsorbed on the surface of the TiO _ 2 nanorod array can broaden the light response range of the catalyst and extend from the ultraviolet light area to the visible light area. TiO _ 2: Yb ~ (3 +), Er ~ (3 +)/ TiO _ 2NRAs/ CdSe in the composite photocatalyst samples showed excellent photocatalytic performance in the degradation of rhodamine B (RhB). The composite structure not only expands the light absorption range of the photocatalyst, but also inhibits the recombination of the electron-hole pair, and plays a catalytic role in the improvement of the photocatalytic degradation performance. In order to improve the catalytic performance of the nano-structure photocatalyst, a novel composite photocatalyst TiO _ 2-G/ TiO _ 2 NRAs: Eu ~ (3 +), Tb ~ (3 +)/ Cs2CO3/ CdS was designed based on the carbon fiber cloth as the substrate and the doping of the rare-earth element Eu ~ (3 +) and Tb ~ (3 +) on the nanorod array grown on the carbon fiber. The photocatalytic degradation of TiO _ 2-G/ TiO _ 2 NRAs: Eu ~ (3 +), Tb ~ (3 +)/ Cs2CO _ 3/ CdS was determined as the target pollutant. It was found that TiO _ 2-G/ TiO _ 2NRAs: Eu ~ (3 +), Tb ~ (3 +)/ Cs2CO _ 3/ CdS exhibited significantly enhanced photocatalytic performance. The increase of the photocatalytic activity of the sample is largely due to the presence of the rare-earth ions Eu ~ (3 +) and Tb ~ (3 +), which can be excited by the ultraviolet light, and a higher intensity visible light can be absorbed by the CdS, resulting in more photo-generated carriers. In addition, the graphene and cesium carbonate (Cs2CO3) play an important role in accelerating the electron transport in the light-catalyzed reaction process. The photocatalyst is grown on the carbon cloth and is beneficial to the recovery and the reuse of the catalyst. As a high-performance light-absorbing layer, the organic perovskite material can absorb most of the sunlight with the wavelength between 350 nm and 800 nm, and the composite structure photocatalyst TiO _ 2 NRAs/ CH3NH3PbI3/ Cu2O is prepared by using the carbon fiber cloth as the substrate. The energy band between Ti O _ 2NRAs, CH3NH3PbI3 and Cu2O in the composite structure photocatalyst TiO _ 2NRAs/ CH3NH3PbI3/ Cu2O can form a bottom-up energy level difference, which is beneficial to the transfer of electrons; under the irradiation of a xenon lamp, the sample TiO2 NRAs/ CH3NH3Pb I3/ Cu2O shows excellent photocatalytic degradation activity. The application of the two-dimensional structure TiO _ 2 nanosheet array with high specific surface area and good electrical conductivity is rare in the photocatalytic degradation. In particular, that nano-sheet array is grown on the carbon fiber cloth, so that the 3D structure can be formed to improve the specific surface area of the catalyst. So we designed the heterogeneous structure of the photocatalyst TiO _ 2 NSAs/ Cu2O. The morphology, structure and photocatalytic degradation of the prepared sample were characterized.
【学位授予单位】：济南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36;O644.1
【参考文献】
相关期刊论文 前3条
1 廖建军;李士普;曹献坤;曹阳;林仕伟;;有序TiO_2纳米管阵列光催化性能研究进展[J];化工进展;2011年09期
2 刘晶冰;燕磊;白文荣;冯惠谦;王R加，
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