本文關(guān)鍵詞：摻氮、還原石墨烯量子點的一步溫和制備及其環(huán)境催化應(yīng)用研究　出處：《中國科學(xué)院大學(xué)(中國科學(xué)院過程工程研究所)》2017年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 還原石墨烯量子點 摻氮 無金屬芬頓 一步制備 環(huán)境催化

【摘要】：以氧化石墨烯(GO)為原料,通過一步還原制備得到摻氮、還原性的石墨烯量子點(Nitrogen-doped reduced graphene oxide quantum dots,N-rGQDs),其具有良好的熒光性能、化學(xué)穩(wěn)定性及生物兼容性,目前已被廣泛應(yīng)用于生物成像、光催化、能量轉(zhuǎn)換等領(lǐng)域。然而,N-rGQDs的制備通常采用較復(fù)雜、高能耗的兩步法,且N-rGQDs表面結(jié)構(gòu)可控性差。因此,本課題提出了一種溫和、一步制備N-rGQDs的綠色制備方法,且在制備過程中同時實現(xiàn)尺寸、結(jié)構(gòu)可控;制備得到的量子點具有良好的環(huán)境催化應(yīng)用前景,本課題對其在環(huán)境催化領(lǐng)域的催化性能和機理進行了探討和分析,取得了以下創(chuàng)新性成果:1)在常溫常壓下,利用無金屬芬頓切割制得N-rGQDs,N-rGQDs切割制備過程進行的跟蹤、分析和監(jiān)控結(jié)果顯示,發(fā)現(xiàn)氧化石墨烯量子點的氧化損傷有一定修復(fù),其含有的C-O鍵和C=O鍵降低了 21%,并成功實現(xiàn)了對芳環(huán)氮(Nar)、叔胺氮[Ar-N-(CH3)2]以及氨基氮(C-NH2)三種主要含氮結(jié)構(gòu)的有效控制。因N-rGQDs具有優(yōu)異的催化性能,本文將其應(yīng)用在了臭氧催化體系,并通過計算化學(xué)手段對催化機理進行了分析探討,得出N-rGQDs的三種N結(jié)構(gòu)中Nar為主要活性位點,Ar-N-(CH3)2為輔助活性位點,為定向調(diào)控和制備高效催化劑提供了思路。2)設(shè)計、制備并最終獲得了一種光催化活性較強的多孔C3N4/N-rGQDs復(fù)合光催化劑,并考察了 N-rGQDs結(jié)構(gòu)、負(fù)載量對催化性能的影響。復(fù)合光催化劑的光催化性能對照組提升1.8倍,從不同N-rGQDs結(jié)構(gòu)、N-rGQDs負(fù)載量等角度探討了催化機理,發(fā)現(xiàn)N-rGQDs中的Nar結(jié)構(gòu)最有利于促進催化活性,通過優(yōu)化條件,N-rGQDs的最佳負(fù)載量為 gN-rGQDs/g多孔C3N4=3.4× 10-5。3)選取最優(yōu)結(jié)構(gòu)的N-rGQDs及負(fù)載條件,制備得到N-rGQDs與不同結(jié)構(gòu)C3N4復(fù)合的光催化材料,并主要從材料物理形貌特點和化學(xué)鍵改變情況兩個角度考察不同C3N4結(jié)構(gòu)對光催化性能的影響。體相C3N4/N-rGQD5、多孔C3N4/N-rGQD5以及納米片層C3N4/N-rGQD5三種材料作為催化劑時,目標(biāo)污染物的去除率依次為53.8%,98.0%和99.0%。由此可見,具有多孔和納米片層結(jié)構(gòu)的復(fù)合材料有利于促進材料的復(fù)合效率。
[Abstract]:Using graphene oxide (GOO) as raw material, nitrogen was prepared by one step reduction. Reduced graphene quantum dots Nitrogen-doped reduced graphene oxide quantum dots. N-rGQDsO, with good fluorescence properties, chemical stability and biocompatibility, has been widely used in biological imaging, photocatalysis, energy conversion and other fields. The preparation of N-rGQDs is usually by two-step method with complex and high energy consumption, and the surface structure of N-rGQDs has poor controllability. Therefore, a mild method is proposed in this paper. The green preparation method of N-rGQDs is one-step, and the size and structure of N-rGQDs are controlled simultaneously in the preparation process. The prepared QDs have a good prospect of environmental catalysis. In this paper, the catalytic performance and mechanism of QDs in the field of environmental catalysis are discussed and analyzed. At room temperature and atmospheric pressure, N-rGQDsN-rGQDs were obtained by non-metal Fenton cutting. The results showed that the process of N-rGQDsN-rGQDs was tracked, analyzed and monitored. It was found that the oxidative damage of graphene oxide QDs was repaired to some extent, and the C-O bond and Cno bond contained in the QDs were reduced by 21%, and the aryl cyclic nitrogen Naran and tertiary amine nitrogen were successfully realized. [Ar-N-(CH3)2] and amino nitrogen C-NH _ 2) were effectively controlled because N-rGQDs had excellent catalytic performance. In this paper, the catalytic mechanism of N-rGQDs was analyzed and discussed by means of computational chemistry. It was found that Nar was the main active site in the three N structures of N-rGQDs. Ar-N-(CH3)2 is the auxiliary active site, which provides the design of orientation regulation and preparation of high activity catalyst. 2). A porous C3N4 / N-rGQDs composite photocatalyst with strong photocatalytic activity was prepared and the structure of N-rGQDs was investigated. The effect of loading amount on the catalytic performance. The photocatalytic performance of the composite photocatalyst was 1.8 times higher than that of the control group. The catalytic mechanism was discussed from the different N-rGQDs structure and the loading amount of N-rGQDs. It was found that the structure of Nar in N-rGQDs was the most favorable to promote the catalytic activity by optimizing the conditions. The optimal loading amount of N-rGQDs is gN-rGQDs/g porous C3N4N 3.4 脳 10-5.3) the optimal structure N-rGQDs and loading conditions are selected. N-rGQDs and C _ 3N _ 4 with different structures were prepared. The effects of different C _ 3N _ 4 structures on photocatalytic properties were investigated from the aspects of physical morphology and chemical bond changes. The bulk C _ 3N _ 4 / N-rGQD5 was investigated. When porous C _ 3N _ 4 / N-rGQD _ 5 and nano-scale C _ 3N _ 4 / N _ r GQD _ 5 were used as catalysts, the removal efficiency of target pollutants was 53.8%. It can be seen that the composite materials with porous and nanolamellar structures can promote the composite efficiency.
【學(xué)位授予單位】：中國科學(xué)院大學(xué)(中國科學(xué)院過程工程研究所)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TQ127.11;X505;O643.36
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本文編號：1379338