本文關(guān)鍵詞： 介孔單晶TiO_2 氫氣 貴金屬負(fù)載 光催化降解 ZnO 壓電　出處：《上海師范大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：近年來,隨著全球能源的過度消耗和環(huán)境的日益惡化,能源和環(huán)境問題是目前世界各國普遍面臨而亟待解決的兩大問題。光催化技術(shù)可用于全分解水制氫以及凈化環(huán)境污染物而得到廣泛關(guān)注。氫氣作為高能燃料,越來越受到人們的關(guān)注,是理想的清潔能源。光催化制氫是一種成本低廉、集光轉(zhuǎn)換與能量存儲于一體的現(xiàn)代技術(shù)。光催化技術(shù)對環(huán)境污染物的凈化處理具有獨(dú)特的優(yōu)勢,在環(huán)保和環(huán)境治理方面具有重大的研究意義。目前光催化材料研究存在的主要問題包括:(1)研究工作主要集中在粉體催化劑,其存在的主要缺點(diǎn)是分離困難,開發(fā)薄膜光催化材料是解決上述問題方法之一;(2)光催化材料本身的光響應(yīng)范圍影響光催化材料對太陽光的利用,拓寬其光吸收范圍是研究重點(diǎn);(3)光生電子和空穴的復(fù)合是影響光催化劑性能的主要因素之一,如何設(shè)計(jì)有效的光催化劑結(jié)構(gòu),促進(jìn)光生電子和空穴的分離,是光催化技術(shù)應(yīng)用的關(guān)鍵。本論文針對光催化材料存在的上述關(guān)鍵問題進(jìn)行了以下三方面的研究:(1)利用拓?fù)滢D(zhuǎn)化法制備介孔單晶二氧化鈦薄膜;介孔單晶材料有著多孔、大比表面積和單晶結(jié)構(gòu),有利于電子傳輸?shù)墓餐瑑?yōu)點(diǎn),能夠顯著的提高光催化性能。本節(jié)通過調(diào)變Ti與F的比和煅燒溫度對薄膜的形貌和晶相進(jìn)行了調(diào)控;利用XRD、SEM、TEM、XPS等現(xiàn)代分析技術(shù)對薄膜的結(jié)晶度、晶型、形貌等進(jìn)行了分析,并以乙二醇為犧牲劑、硫酸鈉為電解質(zhì),對介孔單晶TiO2的光電催化產(chǎn)氫活性進(jìn)行了測試。(2)利用拓?fù)滢D(zhuǎn)化法制備了Au納米顆粒修飾的介孔單晶TiO2薄膜;在可見光下,Au納米顆粒對可見光(400-800 nm)具有等離子共振效應(yīng),較多的界面熱電子會在Au納米粒子表面產(chǎn)生,使熱電子從Au納米粒子表面轉(zhuǎn)移到二氧化鈦的導(dǎo)帶上,肖特基勢壘不僅有助于熱電子聚集在TiO_2的導(dǎo)帶上,而且能有效防止熱電子重新返回到Au表面,從而使光催化產(chǎn)生的電子和空穴易于分離,顯著提高了樣品在可見光下的光催化性能。(3)壓電驅(qū)動(dòng)光生電荷的分離是一個(gè)非常有效的提高光催化劑催化效率的方式。我們在這一節(jié)中研究了流體誘導(dǎo)ZnO壓電性對其光催化性能的影響;制備ZnO納米棒陣列垂直生長在三維泡沫鎳襯底上,通過控制磁力攪拌器的攪拌速率,使液體在Ni泡沫骨架之間形成渦流,溶液的流動(dòng)導(dǎo)致納米棒端面形變,從而激發(fā)ZnO陣列壓電效應(yīng),驅(qū)動(dòng)ZnO光生電子和空穴的分離,提高其光催化活性。實(shí)驗(yàn)結(jié)果表明提高攪拌速率,可以顯著提高有機(jī)污染物的光催化氧化速率。這項(xiàng)工作為設(shè)計(jì)和制造新的壓電催化材料提供了一種新的思路。
[Abstract]:In recent years, with the excessive consumption of global energy and the worsening of the environment, Energy and environment problems are two major problems that countries all over the world are facing and need to be solved. Photocatalytic technology can be used in total decomposition of water to produce hydrogen and purify environmental pollutants. Hydrogen is used as a high-energy fuel. Photocatalytic hydrogen production is a modern technology with low cost and integrated light conversion and energy storage. Photocatalytic technology has unique advantages in the purification and treatment of environmental pollutants. It is of great significance in the field of environmental protection and environmental control. At present, the main problems in the research of photocatalytic materials include: 1) the research work is mainly focused on powder catalysts, and its main disadvantage is the difficulty of separation. The development of thin film photocatalytic materials is one of the methods to solve the above problems. Broadening the range of photoabsorption is one of the main factors that influence the performance of photocatalyst. How to design an effective structure of photocatalyst to promote the separation of photogenerated electrons and holes is one of the main factors that affect the performance of photocatalyst. In this paper, the following three aspects of research on the above key problems of photocatalytic materials are carried out: 1) the mesoporous single crystal TIO _ 2 thin films are prepared by topological transformation method, and the mesoporous single crystal materials are porous. Large specific surface area and single crystal structure are beneficial to the common advantages of electron transport and can significantly improve the photocatalytic performance. In this section, the morphology and crystal phase of the films are regulated by adjusting the ratio of Ti to F and calcining temperature. The crystallinity, crystal form and morphology of the films were analyzed by means of modern analysis techniques such as XRDX, SEMX, TM, XPS, etc., with ethylene glycol as the sacrificial agent, sodium sulfate as electrolyte, etc. The photocatalytic hydrogen production activity of mesoporous single crystal TiO2 was tested. 2) au nanoparticles modified mesoporous single crystal TiO2 thin films were prepared by topological transformation method, and au nanoparticles exhibited plasmon resonance effect on visible light of 400-800 nm. A large number of interface hot electrons are produced on the surface of au nanoparticles, which makes the hot electrons transfer from au nanoparticles to the conduction band of titanium dioxide. Schottky barrier not only helps the hot electrons to accumulate in the conduction band of TiO_2. Moreover, it can effectively prevent hot electrons from returning back to the au surface, which makes the electrons and holes produced by photocatalysis easy to separate. It is a very effective way to improve the photocatalytic efficiency of photocatalyst by improving the photocatalytic performance of the sample under visible light. We have studied the piezoelectric properties of fluid-induced ZnO in this section. The effect on photocatalytic performance; The ZnO nanorod arrays were grown vertically on three dimensional foamed nickel substrates. By controlling the stirring rate of the magnetic agitator, the liquid formed eddies between the Ni foam skeletons, and the flow of the solution resulted in the end deformation of the nanorods. Thus, the piezoelectric effect of ZnO array is excited, the separation of photogenerated electrons and holes is driven, and the photocatalytic activity of ZnO is improved. The experimental results show that the agitation rate is increased. The photocatalytic oxidation rate of organic pollutants can be significantly increased. This work provides a new idea for the design and manufacture of new piezoelectric catalytic materials.
【學(xué)位授予單位】：上海師范大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：O643.36

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本文編號：1549883