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  本文選題：鍶摻雜　切入點：氧化鋅　出處：《華東師范大學》2017年碩士論文

【摘要】：近年來,隨著人類大規(guī)�；纳a(chǎn)和社會的快速發(fā)展,不可再生能源短缺危機以及環(huán)境惡化等問題越來越嚴峻,如此破壞自然平衡,終會遭到反噬,必然危害人類自身,因此,開發(fā)清潔能源和推進可持續(xù)發(fā)展勢在必行。半導體光催化技術作為一種新型綠色技術,它以太陽能作為能源,是用于解決有機污染物對生態(tài)造成的破壞的最有前景的技術之一,因此,受到研究者的廣泛關注。氧化鋅(ZnO)具有直接帶隙(Eg=3.37eV)、較高的氧化還原電位以及較高的電子遷移率,是半導體光催化研究領域中的一種重要材料。研究發(fā)現(xiàn),堿土金屬離子摻雜可以有效地改善半導體光催化劑的光催化性能。然而,關于鍶摻雜氧化鋅可見光光催化性能的研究鮮有報道。因此,對鍶摻雜氧化鋅光催化材料進行研究,對發(fā)展實用、高效的可見光光催化材料具有重要的意義。本文采用溶膠凝膠法制備了不同Sr摻雜量的系列ZnO(SZO)粉體。X射線衍射(XRD)結(jié)果表明,制備的粉體樣品均為六角纖鋅礦ZnO結(jié)構(gòu),具有良好的結(jié)晶度。X射線光電子能譜(XPS)表明Sr以二價鍶離子(Sr2+)的形式存在于ZnO晶格中。掃描電鏡(SEM)結(jié)果表明,Sr摻雜之后,SZO粉體樣品微觀形貌發(fā)生變化、粒徑減小。元素分析(EDS Mapping)結(jié)果表明,Sr元素在SZO粉體中近均勻分布,結(jié)合XRD和XPS的分析結(jié)果,進一步說明了 Sr2+已經(jīng)摻雜進ZnO晶格。紫外可見漫反射光譜(DRS)表明,Sr摻雜提高了 SZO粉體的可見光吸收性能。光致發(fā)光譜(PL)表明,隨著Sr摻雜量的增加,可以觀察到樣品的發(fā)光峰強度減弱。光催化性能評價實驗表明,Sr摻雜導致SZO粉體樣品比未摻雜的ZnO具有更高的光催化活性。其中,F1樣品(前驅(qū)體溶液中Sr與Zn摩爾比為1%)對羅丹明B(RhB)染料表現(xiàn)出最高的光降解效率,在氙燈照射70 min后,RhB染料降解率達97.61%,其可見光催化降解RhB的反應速率約為未摻雜ZnO 的 2.53 倍。另外,考慮到在使用粉體降解有機污染物時,容易造成材料浪費或二次污染,為有效地解決這一問題,本文還采用超聲輔助噴霧熱解法,在玻璃基底上沉積了一系列不同Sr摻雜量的ZnO(SZO)薄膜。XRD結(jié)果表明,薄膜樣品均為六角纖鋅礦ZnO結(jié)構(gòu),且具有(002)擇優(yōu)取向,沒有觀察到Sr、SrO和ZnSr02等有關的衍射峰出現(xiàn),說明Sr2+可能摻入了 ZnO晶格中。EDS Mapping分析表明,Sr元素在SZO薄膜中近均勻分布。UV-Vis吸收譜結(jié)果表明,相比ZnO薄膜,SZO薄膜在可見光區(qū)的光吸收性能增強。PL譜顯示,隨著Sr摻雜量的增加,SZO薄膜的綠發(fā)光峰明顯增強。光催化降解RhB染料的實驗結(jié)果表明,Sr摻雜有利于ZnO薄膜可見光催化效率的提高。所有薄膜樣品中,S3薄膜樣品(前驅(qū)體溶液中Sr、Zn摩爾比為3%)對RhB染料表現(xiàn)出91.99%的最高光降解效率,此外,還對SZO薄膜樣品進行了不同溫度下的空氣退火處理,PL譜結(jié)果進一步驗證了薄膜的綠光發(fā)射峰與VO缺陷有關。
[Abstract]:In recent years, with the large-scale production of human beings and the rapid development of society, the problems such as the shortage of non-renewable energy and the deterioration of the environment are becoming more and more serious.It is imperative to develop clean energy and promote sustainable development.As a new green technology, semiconductor photocatalytic technology, which uses solar energy as energy, is one of the most promising technologies to solve the ecological damage caused by organic pollutants.Zinc oxide (ZnO) has a direct band gap of 3.37 EV, high redox potential and high electron mobility. It is an important material in the field of semiconductor photocatalysis.It is found that alkali earth metal ion doping can effectively improve the photocatalytic performance of semiconductor photocatalysts.However, there are few reports on the visible photocatalytic properties of strontium doped zinc oxide.Therefore, the study of strontium doped zinc oxide photocatalytic materials is of great significance to the development of practical and efficient visible light photocatalytic materials.In this paper, a series of ZnOSZO powders with different Sr doping contents were prepared by sol-gel method. The results of X-ray diffraction show that all the prepared powders have hexagonal wurtzite ZnO structure.Good crystallinity. X-ray photoelectron spectroscopy (XPS) indicates that Sr exists in ZnO lattice in the form of Sr ~ (2 +).The SEM results showed that the microstructure of SZO powder changed and the particle size decreased after Sr doping.The results of elemental analysis show that the element of Sr is nearly uniformly distributed in SZO powders. Combined with the results of XRD and XPS, it is further demonstrated that Sr2 has been doped into ZnO lattice.UV-Vis diffuse reflectance spectroscopy (DRS) shows that Sr doping improves the visible light absorption of SZO powders.Photoluminescence spectra (PLL) show that the intensity of luminescence peak decreases with the increase of Sr doping content.The results of photocatalytic performance evaluation showed that the doped SZO powder had higher photocatalytic activity than the undoped ZnO powder.The F _ 1 sample (Sr / Zn molar ratio of 1 in precursor solution) exhibited the highest photodegradation efficiency for Rhodamine Bhh _ (B) dyes.After irradiation of xenon lamp for 70 min, the degradation rate of RhB dye was 97.61%, and the reaction rate of RhB degradation by visible light was about 2.53 times as high as that of undoped ZnO.In addition, in order to solve this problem effectively, the ultrasonic assisted spray pyrolysis method is used to solve the problem, considering that it is easy to cause material waste or secondary pollution when the powder is used to degrade organic pollutants.A series of ZnO SZO thin films with different Sr doping contents were deposited on glass substrates. The results show that the samples are hexagonal wurtzite ZnO structure and have a preferred orientation of zn002). No diffraction peaks related to SrO, ZnSr02 and so on have been observed.The results indicate that Sr2 may be doped into ZnO lattice. The results of UV-Vis absorption spectra show that the near uniform distribution of Sr elements in SZO films shows that compared with ZnO thin films, the optical absorption properties of ZnO thin films in visible region are better than that of ZnO thin films, and the results of UV-Vis spectra show that the optical absorption properties of SZO thin films are better than that of ZnO thin films in the visible region.The green luminescence peak of SZO thin films increases with the increase of Sr doping content.The experimental results of photocatalytic degradation of RhB dyes show that Sr doping is beneficial to the enhancement of visible light catalytic efficiency of ZnO films.In all thin film samples, the S3 film (Sr-Zn molar ratio in precursor solution is 3) exhibits the highest photodegradation efficiency of 91.99% for RhB dyes.The green emission peaks of SZO films were further verified to be related to VO defects by air annealing at different temperatures.
【學位授予單位】：華東師范大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：O643.36

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