本文選題：納米氧化鋅 + 陽極氧化法��； 參考：《太原理工大學(xué)》2015年碩士論文

【摘要】：隨著環(huán)境問題越來越嚴(yán)重，水污染的處理不斷受到重視，特別是水中難以降解的酚類有機(jī)污染物�，F(xiàn)在研究最多的是光催化氧化降解法，常用的光催化劑是半導(dǎo)體金屬氧化物，其中氧化鋅作為新型寬禁帶半導(dǎo)體材料，因其對紫外光吸收能力強(qiáng)、表面羥基含量高、形貌多樣化等優(yōu)點而逐漸被關(guān)注，且光催化反應(yīng)機(jī)理與TiO2相似，有望取代TiO2。 本研究在氯化銨、無水乙醇、蒸餾水、雙氧水組成的電解液中采用電化學(xué)陽極氧化法制備出高比例暴露極性面的片狀納米氧化鋅，并用于光催化降解苯酚溶液。主要研究內(nèi)容及結(jié)論如下： 1．分別在不同類型的電解液、不同的醇類、不同的電解質(zhì)配制成的電解液中進(jìn)行陽極氧化反應(yīng)，并用SEM表征得到的產(chǎn)物，可知氯化銨作為電解質(zhì)，水和無水乙醇各半作為溶劑制備出來的氧化鋅形貌最好。在此基礎(chǔ)上改變反應(yīng)參數(shù)，通過正交試驗發(fā)現(xiàn)：電壓7V、氧化時間25min、NH4Cl質(zhì)量分?jǐn)?shù)為1.20%、30%雙氧水的體積為0.4ml條件下制備得到的片狀納米氧化鋅晶體結(jié)構(gòu)均一，表面清潔，無團(tuán)聚。 2.對焙燒前后的納米氧化鋅進(jìn)行XRD、FT-IR、BET表征，發(fā)現(xiàn)未焙燒的納米氧化鋅含有大量的羥基和少量的氯離子，還有很強(qiáng)的O－C＝O、－OH紅外吸收峰，其比表面積比焙燒后的氧化鋅大；在325℃焙燒4h后的納米氧化鋅，其XRD衍射峰峰型尖銳、半峰寬較窄，也沒有出現(xiàn)雜峰，即焙燒后的納米氧化鋅的結(jié)晶度和純度都很高，但其O－C＝O、－OH紅外吸收峰的強(qiáng)度變?nèi)酢?3.通過比較焙燒前后實驗制備的納米氧化鋅、商品納米氧化鋅對苯酚溶液的光催化氧化降解效率可以發(fā)現(xiàn)：實驗制備的片狀納米氧化鋅在焙燒前對苯酚的降解效率最高，120min結(jié)束反應(yīng)后對苯酚的降解效率為73.36%。降解主要發(fā)生在前60min，隨著苯酚濃度的降低，催化速率也在降低。在光催化反應(yīng)過程中，，曝入氧氣對苯酚的降解效率也有較大的提高。 4.通過對片狀納米氧化鋅進(jìn)行光致發(fā)光和拉曼光譜分析，可知實驗制備的片狀納米氧化鋅的紫外發(fā)光峰向可見光區(qū)移動且寬化，可見光區(qū)發(fā)光峰也比較強(qiáng)，拉曼光譜也發(fā)生了紅移現(xiàn)象，進(jìn)一步表明實驗制備的片狀納米氧化鋅含有比較多的氧空缺等缺陷，正是這些缺陷使得納米片狀氧化鋅表現(xiàn)出更高的光催化活性。
[Abstract]:As the environmental problems become more and more serious, the treatment of water pollution has been paid more and more attention, especially the phenolic organic pollutants which are difficult to degrade in water. The photocatalytic degradation method is the most widely studied now. The commonly used photocatalyst is semiconductor metal oxide, among which zinc oxide is a new wide band gap semiconductor material, because of its strong absorbability to ultraviolet light and high content of hydroxyl group on the surface. The mechanism of photocatalytic reaction is similar to that of TiO2, which is expected to replace TIO _ 2. In this paper, a high proportion of sheet zinc oxide was prepared by electrochemical anodization in the electrolyte composed of ammonium chloride, anhydrous ethanol, distilled water and hydrogen peroxide, and used for photocatalytic degradation of phenol solution. The main contents and conclusions are as follows: 1. Anodic oxidation reaction was carried out in different electrolytes, different alcohols and different electrolytes respectively. The products were characterized by SEM, and ammonium chloride was used as electrolyte. The morphology of zinc oxide prepared by water and anhydrous ethanol is the best. On this basis, the reaction parameters were changed. It was found by orthogonal experiment that the structure of ZnO was uniform, the surface was clean and there was no agglomeration under the condition that the voltage was 7V, the mass fraction of NH _ 4Cl was 1.20% and the mass fraction of NH _ 4Cl was 1.20% hydrogen peroxide, and the volume of hydrogen peroxide was 0.4ml. 2. The nanometer zinc oxide before and after calcination was characterized by XRDX FT-IR BET. It was found that the uncalcined nanometer zinc oxide contained a large amount of hydroxyl groups and a small amount of chloride ions, and there was also a strong infrared absorption peak of O-C _ (10) O _ (-) O _ (-OH), and its specific surface area was larger than that of the calcined zinc oxide. After calcined at 325 鈩

本文編號：1935923