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  本文關(guān)鍵詞： 軟鉍礦 可控合成 溶液法 異質(zhì)結(jié) 光催化　出處：《安徽理工大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：環(huán)境污染問題日益嚴峻,研制開發(fā)具有高活性的軟鉍礦類可見光催化劑具有重要意義。但目前文獻報道的軟鉍礦材料,其自身結(jié)構(gòu)及功能缺陷從而導(dǎo)致比表面積較小,光生電荷的分離效率較低,可見光催化活性不高。本文主要討論了半導(dǎo)體光催化劑的光催化機理,影響光催化性能的因素,并詳細介紹了提高光催化劑催化性能的途徑以及光催化劑的表征手段,擬采用溫和的水熱合成法,通過水溶性和高粘度的表面活性劑控制反應(yīng)速率,從而誘導(dǎo)納米單元自組裝,制備出具有高比表面積的Bi12MO20-x(M = Si、Ti、Zn)多級結(jié)構(gòu);進一步在材料表面進行半導(dǎo)體復(fù)合,構(gòu)筑相應(yīng)的多級復(fù)合光催化劑,促進光生電荷的高效分離;以羅丹明B可見光催化降解為探針反應(yīng),并結(jié)合XRD、光譜分析等方法,探討產(chǎn)物的微結(jié)構(gòu)對載流子的分離、轉(zhuǎn)移以及催化活性的影響;揭示此類光催化劑高活性的本質(zhì)因素。該項目的實施將豐富軟鉍礦材料的制備技術(shù),并為拓展新型光催化材料提供新的研究思路。本文得出以下結(jié)論:1.實驗通過水熱法合成了多級立方塊狀的Bi12SiO20,并對其形貌與結(jié)構(gòu)進行了 X射線粉末衍射(XRD)、掃描電子顯微鏡(SEM)、能譜(EDS)、高分辨透射電鏡(HRTEM)和X射線光電子能譜(XPS)等表征,同時對其在可見光下降解羅丹明B的光催化過程以及光催化機理進行了詳細的研究。2.實驗通過水熱合成法,基于異質(zhì)結(jié)的設(shè)計理論,成功制備了一種新穎的Bi12ZnO20-Bi2WO6異質(zhì)結(jié)光催化劑,以預(yù)先制備的Bi2WO6為Bi源,通過可控部分沉淀轉(zhuǎn)移法成功制備了一種新穎的Bi12ZnO20-Bi2WO6(BZO-BWO)異質(zhì)結(jié)光催化劑。為了研究其光催化性能,以所制備的BZO-BWO為光催化劑,以羅丹明B(RhB)為模擬染料,研究其對染料的降解效率,并對催化機理進行了研究。3.實驗采用水熱法,使部分沉淀成功轉(zhuǎn)化,制備出了一種新穎的Bi12TiO20-Bi2WO6(BTO-BWO)異質(zhì)結(jié)光催化劑。光催化實驗表明,在紫外-可見光的輻射下Bi12TiO20-Bi2WO6異質(zhì)結(jié)對降解RhB具有超高的光催化活性。最后,本文對其光催化機理進行了討論,分析了光生電荷分離過程。
[Abstract]:The problem of environmental pollution is becoming more and more serious, so it is of great significance to develop visible light catalyst with high activity of soft bismuth ore. However, the structure and function defects of soft bismuth mineral materials reported in the literature at present lead to smaller specific surface area. The separation efficiency of photogenerated charge is low and the visible photocatalytic activity is not high. This paper mainly discusses the photocatalytic mechanism of semiconductor photocatalyst and the factors affecting its photocatalytic performance. The ways to improve the photocatalytic performance and the characterization methods of photocatalyst were introduced in detail. The method of mild hydrothermal synthesis was used to control the reaction rate through water-soluble and high-viscosity surfactants, thus inducing the self-assembly of nano-units. The multistage structure of Bi12MO20-x(M with high specific surface area was prepared, and the semiconductor composite was carried out on the surface of the material, and the corresponding multistage composite photocatalyst was constructed to promote the efficient separation of photogenerated charges. The catalytic degradation of rhodamine B in visible light was used as a probe reaction. The effects of the microstructure of the product on the separation, transfer and catalytic activity of carriers were investigated by means of XRD and spectroscopic analysis. The implementation of this project will enrich the preparation technology of soft bismuth ore materials. In this paper, the following conclusions are drawn: 1. The multilevel cubic bulk Bi12SiO20 has been synthesized by hydrothermal method. The morphology and structure of Bi12SiO20 have been characterized by X-ray powder diffraction (XRD) and scanning electricity (SEM). The electron microscopes were characterized by SEM, EDS, HRTEM (high resolution transmission electron microscopy) and X-ray photoelectron spectroscopy (XPSs). At the same time, the photocatalytic process and photocatalytic mechanism of Rhodamine B were studied in detail. 2. A novel Bi12ZnO20-Bi2WO6 heterojunction photocatalyst was successfully prepared by hydrothermal synthesis based on the design theory of heterojunction. A novel heterojunction photocatalyst, Bi12ZnO20-Bi2WO6WO BZO-BWO-BWO, was successfully prepared by controlled partial precipitation transfer method using pre-prepared Bi2WO6 as Bi source. In order to study its photocatalytic properties, the prepared BZO-BWO was used as photocatalyst and Rhodamine Bhl RhBas as mimic dye. The degradation efficiency of the dye was studied and the catalytic mechanism was studied. 3. A novel heterojunction photocatalyst Bi12TiO20-Bi2WO6WO (BTO-BWOO) was prepared by hydrothermal method. The photocatalytic activity of Bi12TiO20-Bi2WO6 heterogeneity pair degradation of RhB under UV-Vis radiation is very high. Finally, the photocatalytic mechanism is discussed and the process of photogenerated charge separation is analyzed.
【學(xué)位授予單位】：安徽理工大學(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：1514183