本文選題：石墨烯量子點　切入點：鐵酸鋅　出處：《安徽工業(yè)大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：石墨烯量子點(GQDs)是尺寸小于20 nm的石墨烯片,由于量子局域限制和邊界效應(yīng)而表現(xiàn)出很多優(yōu)異的物理、化學(xué)性能。目前已被應(yīng)用于例如熒光探針、光催化、電化學(xué)檢測、生物成像、藥物運輸和傳感器等領(lǐng)域中。本文圍繞GQDs展開,詳述了近年來常用的GQDs制備方法及其生成機理,之后以一水合檸檬酸為原料,合成了GQDs,再通過水熱法將GQDs摻雜進金屬氧化物中,制備出了GQDs-金屬氧化物復(fù)合材料,著重研究了GQDs-金屬氧化物復(fù)合材料的氣敏性能。通過水熱法制備了含有不同GQDs比重的GQDs-ZnFe_2O_4復(fù)合氣敏材料,首先通過掃描電鏡(SEM)、透射電鏡(TEM)以及高分辨投射電鏡(HRTEM)觀察了復(fù)合材料的形貌特征,然后通過X射線衍射(XRD)、熱重分析(TG-DSC)、紅外光譜(FT-IR)、拉曼光譜(Raman)、X射線光電子能譜(XPS)、氮吸附以及孔徑分布等表征手段將摻雜GQDs前后的氣敏材料進行比較,證明GQDs的確已復(fù)合進金屬氧化物材料中。一系列氣敏測試結(jié)果證實了GQDs的加入在降低最佳工作溫度的同時也增大了其對某種或多種氣體的靈敏度。GQDs-ZnFe_2O_4(S-15)復(fù)合氣敏材料在室溫下對1000 ppm丙酮的最大靈敏度為13.31,且響應(yīng)恢復(fù)時間較短,可檢測到丙酮的最低濃度為5 ppm;通過水熱法制備了ZnO和GQDs-ZnO復(fù)合氣敏材料,首先對這些材料進行與GQDs-ZnFe_2O_4復(fù)合氣敏材料相同的表征測試,再將這些復(fù)合材料與純ZnO進行氣敏測試。實驗結(jié)果表明GQDs-ZnO(S-10)復(fù)合氣敏材料在室溫下對1000ppm乙酸氣體的最大靈敏度為642,是純ZnO最大靈敏度的72.1倍,室溫下可以檢測到的乙酸最低濃度為1 ppm。通過水熱法制備了MoO_3和GQDs-MoO_3復(fù)合氣敏材料,在進行表征測試之后再進行氣敏測試。實驗結(jié)果表明GQDs-MoO_3(S-6)復(fù)合氣敏材料對三甲胺氣體的氣敏性最好,選擇性變高的同時靈敏度也有了非常大的提升。在最佳工作溫度230℃時,對1000 ppm三甲胺的最大靈敏度為74.08,是相同工作溫度下,純MoO_3對三甲胺靈敏度的13.9倍,可以檢測到的三甲胺最低濃度為1 ppm。
[Abstract]:Graphene Quantum Dots (GQDs) are graphene wafers with size less than 20 nm, which exhibit many excellent physical and chemical properties due to quantum localization and boundary effects. In the fields of biologic imaging, drug transportation and sensor, this paper focuses on GQDs, describes the preparation methods and formation mechanism of GQDs in recent years, and then uses citric acid monohydrate as raw material. GQDs- metal oxide composites were prepared by hydrothermal doping of GQDs into metal oxides. The gas sensing properties of GQDs- metal oxide composites were studied. GQDs-ZnFe_2O_4 composite gas sensing materials with different GQDs specific gravity were prepared by hydrothermal method. The morphology of the composite was observed by SEM, TEM (TEM) and HRTEM (high resolution projection electron microscope). Then the gas sensing materials before and after doping GQDs were compared by means of X-ray diffraction (XRD), thermogravimetric analysis (TG-DSCN), FT-IR, Raman spectroscopy (Raman spectrum), X-ray photoelectron spectroscopy (XPS), nitrogen adsorption and pore size distribution. It is proved that GQDs has indeed been compacted into metal oxide materials. A series of gas sensing tests have proved that the addition of GQDs not only reduces the optimum operating temperature but also increases its sensitivity to some gas or gases. GQDs-ZnFe2O4S-15) composite gas sensing material. The maximum sensitivity to 1000 ppm acetone at room temperature is 13.31, and the response recovery time is short. The lowest concentration of acetone can be detected to be 5 ppm. ZnO and GQDs-ZnO composite gas sensing materials were prepared by hydrothermal method. The results show that the maximum sensitivity of GQDs-ZnOS-10 / GQDs-ZnOS-10 / GQDs-ZnOS-10 / GQDs-ZnOS-10 / GQDs-ZnOS-10 / GQDs-ZnOS-10 composite is 642 to 1000ppm acetic acid at room temperature, which is 72.1 times higher than that of pure ZnO. The lowest concentration of acetic acid detected at room temperature is 1 ppm. MoO_3 and GQDs-MoO_3 composite gas sensing materials were prepared by hydrothermal method. The results show that the GQDs-MoO3S-6 composite gas sensing material has the best gas sensitivity to trimethylamine gas, and the sensitivity is also greatly improved when the selectivity is higher. At 230 鈩，

本文編號：1567842