二氧化鈦基納米復(fù)合結(jié)構(gòu)的制備及其光催化性能的研究
發(fā)布時間：2019-06-09 20:31
【摘要】：物理化學(xué)性質(zhì)穩(wěn)定,無毒,成本低等優(yōu)勢的存在,讓納米TiO_2半導(dǎo)體在光催化領(lǐng)域得到了很高的重視。作為眾多光催化材料中的最有潛力的金屬氧化物半導(dǎo)體,受到了世界上眾多科研人員的青睞。但是不可否認(rèn),在實(shí)際操作過程當(dāng)中仍然存在著一些不能回避的問題,比如只能被太陽光中的紫外光激發(fā)產(chǎn)生電子和空穴,受激發(fā)產(chǎn)生的電子-空穴對的復(fù)合幾率較大等限制著TiO_2半導(dǎo)體光催化技術(shù)的進(jìn)步。鑒于以上幾點(diǎn),本論文的工作主要是通過水熱法制備TiO_2半導(dǎo)體材料為主,通過尺寸的調(diào)控,采用上下轉(zhuǎn)換發(fā)光元素?fù)诫s,以及與其他半導(dǎo)體進(jìn)行復(fù)合等等,對TiO_2半導(dǎo)體材料進(jìn)行改良研究,本篇論文的研究的主要工作包括以下幾個方面:1.在FTO上,通過稀土元素Yb~(3+)和Er~(3+)的引入,通過水熱法、溶膠-凝膠法等手段構(gòu)建了新型的復(fù)合結(jié)構(gòu)光催化劑TiO_2:Yb~(3+),Er~(3+)/TiO_2 NRAs/CdSe。其中TiO_2:Yb~(3+),Er~(3+)薄膜作為一個媒介,通過上轉(zhuǎn)換過程,將近紅外光轉(zhuǎn)換為可見光;同時,一維結(jié)構(gòu)的TiO_2納米棒陣列具有較高的比表面積,陣列高度有序化,為光生電子的輸運(yùn)提供了快速通道。吸附在TiO_2納米棒陣列表面的CdSe量子點(diǎn)能夠拓寬催化劑的光響應(yīng)范圍,從紫外光區(qū)域延伸到可見光區(qū)域。復(fù)合結(jié)構(gòu)光催化劑樣品TiO_2:Yb~(3+),Er~(3+)/TiO_2 NRAs/CdSe在降解羅丹明B(RhB)方面,展現(xiàn)出較為出色的光催化性能。該復(fù)合結(jié)構(gòu)不僅拓展了光催化劑的光吸收范圍,同時也抑制了其電子-空穴對的復(fù)合,對光催化降解性能的提升起到了促進(jìn)作用。2.為了改善納米結(jié)構(gòu)光催化劑的催化性能,我們以碳纖維布為基底,對生長在碳纖維上的納米棒陣列進(jìn)行稀土元素Eu~(3+)和Tb~(3+)的摻雜,設(shè)計了一種新型的復(fù)合光催化劑TiO_2-G/TiO_2 NRAs:Eu~(3+),Tb~(3+)/Cs2CO3/CdS。羅丹明B作為目標(biāo)污染物用來測定樣品TiO_2-G/TiO_2 NRAs:Eu~(3+),Tb~(3+)/Cs2CO3/CdS的光催化降解活性。研究發(fā)現(xiàn),樣品TiO_2-G/TiO_2 NRAs:Eu~(3+),Tb~(3+)/Cs2CO3/CdS展現(xiàn)出顯著增強(qiáng)的光催化性能表現(xiàn)。樣品的光催化活性如此明顯的提升很大程度上是由于稀土離子Eu~(3+)和Tb~(3+)的存在能夠被紫外光激發(fā),產(chǎn)生了一個強(qiáng)度較高的可見光能夠被CdS吸收,產(chǎn)生更多的光生載流子。此外,石墨烯和碳酸銫(Cs2CO3)在光催化反應(yīng)過程中,在加速電子傳輸方面扮演了重要的角色。光催化劑生長在碳布上,有利于催化劑的回收和重復(fù)使用。3.有機(jī)鈣鈦礦材料作為高性能的光吸收層,能夠吸收波長在350 nm~800 nm之間大部分的太陽光,利用碳纖維布為基底,設(shè)計制備了復(fù)合結(jié)構(gòu)光催化劑TiO_2NRAs/CH3NH3PbI3/Cu2O。復(fù)合結(jié)構(gòu)光催化劑TiO_2 NRAs/CH3NH3PbI3/Cu2O中Ti O_2 NRAs、CH3NH3PbI3、Cu2O三者之間的能帶能夠形成自下而上的能級差,有利于電子的轉(zhuǎn)移;在氙燈的照射下,樣品TiO_2 NRAs/CH3NH3Pb I3/Cu2O表現(xiàn)出出色的光催化降解活性。4.具有高比表面,良好導(dǎo)電性的的二維結(jié)構(gòu)TiO_2納米片陣列在光催化降解方面的應(yīng)用還較為少見。特別是納米片陣列生長在碳纖維布上,能夠形成3D結(jié)構(gòu),去提高催化劑的比表面積。因此我們設(shè)計了異質(zhì)結(jié)構(gòu)的光催化劑TiO_2 NSAs/Cu2O。對制備的樣品的形貌,結(jié)構(gòu)和光催化降解性能進(jìn)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.
【學(xué)位授予單位】：濟(jì)南大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：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.
【學(xué)位授予單位】：濟(jì)南大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：O643.36;O644.1
【參考文獻(xiàn)】
相關(guān)期刊論文 前3條
1 廖建軍;李士普;曹獻(xiàn)坤;曹陽;林仕偉;;有序TiO_2納米管陣列光催化性能研究進(jìn)展[J];化工進(jìn)展;2011年09期
2 劉晶冰;燕磊;白文榮;馮惠謙;王R加，
本文編號：2495880
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