本文關(guān)鍵詞： 溶膠-溶劑熱法 二氧化鈦 改性 光催化 甲基橙　出處：《吉林大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：隨著人們生活水平的不斷提高,越來越多的產(chǎn)品來自于石油、煤炭和天然氣等不可再生的自然資源。同時,產(chǎn)品在原材料的提取、運輸和轉(zhuǎn)化過程中都有可能給環(huán)境帶來負面效應(yīng)。因此,環(huán)境污染和能源短缺現(xiàn)象成為人類目前應(yīng)對的世界性難題。半導(dǎo)體光催化技術(shù)在環(huán)境修復(fù)領(lǐng)域的作為不容忽視,已被證明是降解水體和大氣環(huán)境中有害污染物的有效途徑。在解決能源危機方面,通過光分解水制氫、太陽能電池等方式實現(xiàn)了可再生能源的高效利用。二氧化鈦因其高穩(wěn)定性,無毒性且低成本被認為是非常理想的光催化半導(dǎo)體材料。光催化劑的表面積是決定污染物吸附量的重要因素,直接影響其光催化活性的強弱。由于二氧化鈦納米材料的高表面能使得納米粒子間傾向于聚集以達到體系的平衡狀態(tài),導(dǎo)致納米粉體的團聚現(xiàn)象嚴(yán)重,無法獲得較大的活性表面積。因此,本文采用表面活性劑作為分散劑,并優(yōu)化制備工藝進行改性,以獲得均一分散的二氧化鈦納米體系是十分必要的。主要研究內(nèi)容如下:(1)綜合溶膠-凝膠法和溶劑熱法的制備優(yōu)勢,本論文采用溶膠-溶劑熱改進工藝進行實驗分析。以鈦酸丁酯為鈦源,無水乙醇為溶劑,濃硝酸為抑制劑,按照n(Ti(OR)4):n(C2H5OH):n(H+):n(H2O)=1:15:0.35:4的反應(yīng)物配比,制備納米級二氧化鈦材料。(2)通過單因素實驗與正交實驗相結(jié)合的方式,以樣品對甲基橙的光催化降解率為分析依據(jù),探究溶劑熱溫度、溶劑熱時間、煅燒溫度和煅燒時間對于二氧化鈦光催化活性的影響。正交實驗的結(jié)果表明,最佳工藝參數(shù)是:當(dāng)溶劑熱溫度為150℃,溶劑熱時間為24h,煅燒溫度為450℃,煅燒時間為4h時,樣品的光催化降解率最高,為82.88%。同時XRD、SEM、TEM和EDS的圖像表明,樣品為結(jié)晶度良好的單一銳鈦礦相,無任何雜質(zhì),但分散性一般。(3)在最佳工藝參數(shù)的基礎(chǔ)上,通過控制表面活性劑的種類和含量的不同,探究不同類型表面活性劑的最佳投料比,從而確定用于二氧化鈦納米粉體改性的最佳分散劑,并通過XRD、SEM、TEM和EDS等技術(shù)對樣品進行表征。實驗結(jié)果表明,不同類型表面活性劑的最佳投料比(與鈦酸丁酯的質(zhì)量比)分別是:陽離子表面活性劑CTAB為1:60、陰離子表面活性劑SDBS為1:30、非離子型表面活性劑PEG為1:30。不同類型表面活性劑在最佳投料比條件下,CTAB改性納米二氧化鈦、SDBS改性納米二氧化鈦、PEG改性納米二氧化鈦相比于未改性納米TiO_2的光催化降解率分別提高了16.28%、13.41%、9.23%。樣品均為純凈的、結(jié)晶度較好的單一銳鈦礦相,且CTAB的改性效果明顯好于SDBS和PEG,得到的納米粒子均一分散。
[Abstract]:As people's living standards continue to improve, more and more products come from non-renewable natural resources such as oil, coal and natural gas. At the same time, the products are extracted from raw materials. Therefore, environmental pollution and energy shortage have become a worldwide problem for mankind to deal with. Semiconductor photocatalytic technology can not be ignored in the field of environmental remediation. Has proven to be an effective way to degrade harmful pollutants in water and the atmospheric environment. In resolving the energy crisis, hydrogen is produced by photodecomposition of water, Solar cells and other ways to achieve the efficient use of renewable energy. Titanium dioxide because of its high stability, Non-toxic and low-cost photocatalytic semiconductor materials are considered ideal. The surface area of photocatalysts is an important factor in determining the adsorption capacity of pollutants. Because of the high surface energy of TIO _ 2 nanoparticles tend to aggregate in order to achieve the equilibrium state of the system, which leads to the serious agglomeration of nano-powders. Therefore, the surfactant was used as dispersant and the preparation process was optimized. It is necessary to obtain homogeneous and dispersed TIO _ 2 nanosystems. The main research contents are as follows: 1) Synthesis advantages of sol-gel method and solvothermal method. In this paper, the sol-sol-thermal process was used to improve the experimental results. Using butyl titanate as titanium source, anhydrous ethanol as solvent, and concentrated nitric acid as inhibitor, the ratio of reactants of 1 15: 0. 35: 4 was determined according to the ratio of the reactants of nTiorao 4: C _ 2H _ 5OH _ 1: h _ 2O _ 1: 1 15: 0.35: 4. The preparation of nanometer titanium dioxide material. 2) through the combination of single factor experiment and orthogonal experiment, based on the photocatalytic degradation rate of methyl orange, the solvothermal temperature and solvothermal time were studied. Effects of calcination temperature and calcination time on the photocatalytic activity of titanium dioxide. The results of orthogonal experiment show that the optimum technological parameters are as follows: the solvothermal temperature is 150 鈩，

本文編號：1517917