本文選題：碳點(diǎn) + 多種光色��； 參考：《上海師范大學(xué)》2017年碩士論文

【摘要】：熒光碳點(diǎn)與一些傳統(tǒng)量子點(diǎn)和有機(jī)染料相比,具有一些獨(dú)特的優(yōu)勢,如毒性低、水溶性好、光漂白性好、生物相容性好等,故受到越來越多的人關(guān)注,但一些碳點(diǎn)的制備方法復(fù)雜、熒光效率不高、長波熒光發(fā)射碳點(diǎn)尤其是紅光甚至近紅外光碳點(diǎn)少,因此,探究一種簡的便方法制備高量子效率、多種光色發(fā)射的碳點(diǎn)很有必要。本文針對以上問題采用不同的制備方法制備了較高熒光效率的碳點(diǎn),采用一步熱解法制備高熒光效率的黃綠光碳點(diǎn),又采用溶劑熱法制備多光色發(fā)射的碳點(diǎn)。論文的主要研究內(nèi)容和結(jié)果如下:1.以檸檬酸為碳源、尿素提供氮源一步熱解法制備高熒光效率的黃綠光碳點(diǎn)。并對碳點(diǎn)的形貌、粒徑、表面基團(tuán)、發(fā)光性質(zhì)等進(jìn)行表征測試,發(fā)現(xiàn)碳點(diǎn)分布均勻,不團(tuán)聚,粒徑約為5 nm,表面含有大量親水性有機(jī)基團(tuán),熒光量子效率高達(dá)78.3%;其激發(fā)峰為291 nm、360 nm、460 nm,發(fā)射主峰位于533 nm,調(diào)節(jié)激發(fā)波長365 nm~465 nm,其發(fā)射主峰保持不變,而在465 nm~525 nm,發(fā)射主峰紅移;探究了制備黃綠光碳點(diǎn)最佳條件,得知最佳制備條件為原料檸檬酸與尿素摩爾比1:4、反應(yīng)溫度為200℃、反應(yīng)時間為2 h;同時探究了碳點(diǎn)制備過程發(fā)生的變化,得知首先生成碳點(diǎn)前驅(qū)體,進(jìn)一步反應(yīng)得到碳點(diǎn);研究了不同pH環(huán)境、不同有機(jī)溶劑、不同濃度無機(jī)鹽離子環(huán)境、紫外光照射不同時間對碳點(diǎn)發(fā)光的影響,結(jié)果表明強(qiáng)酸、強(qiáng)堿環(huán)境對碳點(diǎn)熒光影響較大;極性較大溶劑中呈現(xiàn)黃綠光,且極性越大,發(fā)光越強(qiáng),而在極性小的溶劑中大多呈現(xiàn)藍(lán)光發(fā)射,甚至在極性極小的溶劑中不發(fā)光;其耐鹽性及光漂白性極好;用其培養(yǎng)藻類,藻類生長良好證明碳點(diǎn)毒性低;將碳點(diǎn)用于打印、防偽、復(fù)合材料、光電材料,取得很好的效果。2.以檸嗪酸為共同碳源,采用一步溶劑熱法制備了藍(lán)、黃、紅三種光色的碳點(diǎn)。三種碳點(diǎn)粒徑均在5 nm以下,表面都有大量有機(jī)基團(tuán),藍(lán)光碳點(diǎn)激發(fā)主峰為354 nm,此時發(fā)射主峰峰為458 nm,黃光碳點(diǎn)激發(fā)主峰為494 nm,發(fā)射主峰為562 nm,紅光碳點(diǎn)激發(fā)主峰是621 nm,發(fā)射峰為655 nm,三種碳點(diǎn)的熒光量子效率都較高,藍(lán)光為58.7%、黃光為34.5%、紅光為23.8%。調(diào)節(jié)激發(fā)波長發(fā)現(xiàn),藍(lán)、紅碳點(diǎn)發(fā)射波長對激發(fā)波長有一定的依耐性,而改變激發(fā)波長黃光碳點(diǎn)的發(fā)射峰保持不變。對三種碳點(diǎn)的耐鹽性、光穩(wěn)定性、毒性進(jìn)行了測試,結(jié)果表明:三種碳點(diǎn)耐鹽性好、光漂白性好、毒性低。將三種碳點(diǎn)用作熒光墨水、制備固態(tài)復(fù)合發(fā)光材料、LDE領(lǐng)域均收到不錯的效果。
[Abstract]:Compared with some traditional quantum dots and organic dyes, fluorescent carbon dots have some unique advantages, such as low toxicity, good water solubility, good photobleaching, good biocompatibility and so on. However, the preparation methods of some carbon spots are complex, the fluorescence efficiency is not high, and the long wave fluorescence emission carbon points, especially the red light and even the near infrared carbon spots, are few. Therefore, it is necessary to explore a simple method to prepare carbon dots with high quantum efficiency and various photochromatic emission. In order to solve the above problems, the carbon spots with high fluorescence efficiency were prepared by different preparation methods, the yellowish green carbon spots with high fluorescence efficiency were prepared by one step pyrolysis, and the carbon spots with multiple photochromatic emission were prepared by solvothermal method. The main contents and results of this paper are as follows: 1. Using citric acid as carbon source, urea provides nitrogen source for one step pyrolysis to prepare yellowish-green carbon spots with high fluorescence efficiency. The morphology, particle size, surface group and luminescence properties of the carbon spots were characterized. It was found that the carbon spots were uniformly distributed and not agglomerated, and the particle size was about 5 nm, and there were a large number of hydrophilic organic groups on the surface. The fluorescence quantum efficiency is as high as 78.3 nm, the excitation peak is 291Nm ~ 360nm ~ (-1), the main emission peak is located at 533nm, and the excitation wavelength is nm~465 ~ (mm), and the main emission peak remains unchanged, while at 465 nm~525 nm, the main emission peak is red-shifted. The optimum conditions for preparing yellow-green carbon spots are investigated. The optimum preparation conditions are as follows: the molar ratio of citric acid to urea is 1: 4, the reaction temperature is 200 鈩，

本文編號：1819030