本文選題：TiO_2空球 + Au/TiO_2　； 參考：《浙江師范大學(xué)》2015年碩士論文

【摘要】：由于其優(yōu)異且穩(wěn)定的物理和化學(xué)性能,二氧化鈦(TiO2)已在諸多領(lǐng)域中有了實(shí)際應(yīng)用,如太陽能電池、光催化、光子晶體、氣敏傳感器、自清潔器件和生物醫(yī)藥等領(lǐng)域。就TiO2在光催領(lǐng)域的應(yīng)用而言,其性能受晶相、禁帶寬、顆粒尺寸、比表面積及結(jié)晶度等多個因素的影響,合成具有高結(jié)晶度、小尺寸、高比表面的銳鈦礦TiO2納米光催化劑將具有最佳的應(yīng)用前景。同時,為了提高反應(yīng)物在催化體系中的擴(kuò)散,設(shè)計中空的催化劑結(jié)構(gòu)也能顯著提高催化劑的催化效率。本論文以制備高性能中空結(jié)構(gòu)的TiO2為目標(biāo),設(shè)計了一種“沉積-自刻蝕-再沉積”的合成方法,成功地制備了一種鑲嵌在SiO2薄層中的TiO2空球；在此基礎(chǔ)上,我們通過對材料進(jìn)行不同溫度的水熱處理,獲得了不同殼層厚度的TiO2中空結(jié)構(gòu)；同時,我們通過在TiO2空球內(nèi)原位生長Au納米顆粒,制備了一系列尺寸可控的具有yolk@shell結(jié)構(gòu)的Au/TiO2空球。論文的具體內(nèi)容主要分為以下三個方面：1)在微乳體系中,我們通過讓有機(jī)硅烷和正硅酸乙酯同時水解,得到尺寸均勻的SiO2有機(jī)/無機(jī)小球模版。在該模板表面沉積TiO2時,TiO2的表面沉積可引發(fā)模板的自刻蝕,從而一步實(shí)現(xiàn)了TiO2空心納米結(jié)構(gòu)的制備。同時,少量被刻蝕的SiO2可再沉積到TiO2表面形成薄層。在SiO2薄層的保護(hù)下,TiO2空球可在900℃的高溫下進(jìn)行晶化,可獲得銳鈦礦相、小尺寸(5～8nm)、高結(jié)晶度的TiO2晶粒。同時,在退火過程中含氮有機(jī)硅烷中的氮元素可進(jìn)入TiO2晶格內(nèi)部,可形成氮摻雜TiO2,從而使得材料可對紫外光和可見光均能響應(yīng)。我們通過TEM、SEM、XRD、XPS、FTIR spectrum、TGA等一系列手段對材料進(jìn)行了表征。最后通過光催化降解染料(羅丹明B)證明材料具有優(yōu)異的光催化性能。2)通過將1)中高溫處理前的TiO2/SiO2復(fù)合空心納米球作為前驅(qū)體,我們發(fā)現(xiàn)通過使用熱水可刻蝕樣品中的Si02成分,該過程可導(dǎo)致Ti02殼層小顆粒的重構(gòu),從而可得到一系列具有超薄結(jié)構(gòu)的Ti02空心球。我們采用TEM、HTEM、 XRD、BET等手段對樣品進(jìn)行了分析,提出了樣品“刻蝕-重構(gòu)”的生長機(jī)理。通過光催化降解染料和光催化制備氫氣等性能測試,我們分析了Ti02空球殼層厚度與其光催化性能之間的影響關(guān)系。3)通過在有機(jī)／無機(jī)SiO2小球模板中引入氨基硅烷,我們發(fā)現(xiàn)Ti02空球內(nèi)可吸附大量氨基基團(tuán)。利用氨基基團(tuán)的還原性,我們在Ti02空球內(nèi)部成功還原了氯金酸,從而可在空球內(nèi)原位生長納米金顆粒。通過對反應(yīng)物濃度、反應(yīng)時間、超聲過程、加熱條件及加熱時間的細(xì)致優(yōu)化,我們實(shí)現(xiàn)了單個金納米顆粒在Ti02內(nèi)的可控生長,并可選擇性制備不同大小的金納米顆粒。樣品經(jīng)過高溫處理,可得到一系列具有yolk@shell結(jié)構(gòu)的Au/TiO2中空核殼納米顆粒。通過光解水實(shí)驗測試材料性能,發(fā)現(xiàn)生長金納米顆粒后材料催化制氫的能力顯著增強(qiáng),同時發(fā)現(xiàn)單位時間產(chǎn)氫的量和金顆粒的大小成正比關(guān)系。綜上所述,我們制備了氮摻雜的TiO：空心納米球和以其為前驅(qū)體的超薄殼層Ti02空球,及Au/TiO2的yolk@shell納米材料,材料均表現(xiàn)出良好的光催化性能。這三種材料分別從拓寬太陽光響應(yīng)范圍、比表面和高效分離電子和空穴等三個方面提高了Ti02納米材料的催化活性。上述基于Ti02空心納米材料的研究有助于促進(jìn)Ti02基納米材料向?qū)嵱梅较虻陌l(fā)展。
[Abstract]:Because of its excellent and stable physical and chemical properties, titanium dioxide (TiO2) has been applied in many fields, such as solar cells, photocatalysis, photonic crystals, gas sensors, self cleaning devices and biomedicine. The performance of TiO2 in the field of light is subject to crystal phase, forbidden bandwidth, particle size, specific surface area. The synthesis of anatase TiO2 nanoscale photocatalyst with high crystallinity, small size and high specific surface will have the best prospect of application. At the same time, in order to improve the diffusion of the reactant in the catalytic system, the design of the hollow catalyst structure can also improve the catalytic efficiency of the catalyst. A "deposition self etching redeposition" method was designed for the hollow structure of TiO2. A TiO2 hollow sphere embedded in a SiO2 thin layer was successfully prepared. On this basis, we obtained a TiO2 hollow structure with different shell thickness by heat treatment at different temperatures. In situ Au nanoparticles were grown in the TiO2 empty sphere, and a series of Au/TiO2 empty spheres with yolk@shell structure were prepared. The main contents of the paper were divided into three aspects: 1) in the microemulsion system, we obtained the homogeneous SiO2 organic / inorganic pellet template by hydrolyzing organosilane and tetraethyl orthosilicate at the same time. When TiO2 is deposited on the surface of the template, the surface deposition of TiO2 can lead to the self etching of the template, thus the preparation of the TiO2 hollow nanostructure is realized in one step. At the same time, a small amount of the etched SiO2 can be redeposited to the surface of the TiO2 to form a thin layer. Under the protection of the thin layer of SiO2, the TiO2 space ball can crystallize at 900 centigrade temperature, and the anatase phase can be obtained. The size (5 ~ 8nm), high crystallinity of TiO2 grain. At the same time, nitrogen in the nitrogen containing organo silane in the annealing process can enter the TiO2 lattice, and can form a nitrogen doped TiO2, so that the material can respond to both ultraviolet and visible light. We characterize the material through a series of means such as TEM, SEM, XRD, XPS, FTIR spectrum, TGA and so on. After photocatalytic degradation of dye (Luo Danming B), the material has excellent photocatalytic performance.2) by using TiO2/SiO2 composite hollow nanospheres as precursors before high temperature treatment in 1), we found that using hot water to etch Si02 components in the sample, this process can lead to the reconstruction of small particles of Ti02 shell, and thus a series of products can be obtained. Ti02 hollow spheres with ultrathin structures are analyzed by means of TEM, HTEM, XRD, BET and so on. The growth mechanism of the sample "etching reconfiguration" is put forward. The performance tests of the photocatalytic dye and photocatalytic preparation of hydrogen are put forward. The relationship between the thickness of the shell layer of Ti02 and the photocatalytic properties of the Ti02 is analyzed.3). Through the introduction of amino silane in the organic / inorganic SiO2 pellet template, we found that a large number of amino groups can be adsorbed in the Ti02 empty sphere. Using the reducibility of the amino group, we have successfully reduced chloric acid inside the Ti02 empty sphere, so that the nano gold particles can be grown in the empty sphere. With the careful optimization of thermal conditions and heating time, we have realized the controllable growth of single gold nanoparticles in Ti02, and can selectively prepare different sizes of gold nanoparticles. After high temperature treatment, a series of Au/TiO2 hollow core shell nanoparticles with yolk@shell structure can be obtained. The properties of the materials are tested by the photodissociation test. The capacity of catalytic hydrogen production by the present growth gold nanoparticles is significantly enhanced and the amount of hydrogen production per unit time is proportional to the size of the gold particles. In summary, we have prepared the nitrogen doped TiO: hollow nanospheres and the ultra-thin shell Ti02 hollow spheres with its precursors, and the yolk@shell nanomaterials of Au/TiO2. The three materials have improved the catalytic activity of Ti02 nanomaterials from three aspects, such as broadening the response range of the solar light, the surface and the high efficiency separation of electrons and holes, respectively. The research based on the Ti02 hollow nanomaterials can help to promote the development of the Ti02 based nanomaterials in the practical direction.
【學(xué)位授予單位】：浙江師范大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：O643.36;TB383.1

【共引文獻(xiàn)】

相關(guān)期刊論文 前9條

1 曾愛香;羅麗;胡凱龍;;溶膠-凝膠法制備納米TiO_2粉體的研究進(jìn)展[J];材料導(dǎo)報;2013年19期

2 景茂祥;顏遠(yuǎn)瞻;平昱航;李立康;;介孔二氧化鈦微球光催化劑的結(jié)構(gòu)與性能[J];材料科學(xué)與工程學(xué)報;2014年01期

3 唐榮芝;王松林;張元卓;陳彤;王公應(yīng);;乙酸氧鈦對碳酸二甲酯與苯酚酯交換的催化作用[J];高等學(xué)�；瘜W(xué)學(xué)報;2014年11期

4 李海燕;龔丹;曾慶，

本文編號：1944667