水溶性碳量子点的制备及防伪应用

以壳聚糖为原料,采用水热法一步制备水溶性的荧光碳量子点（CQDs）,考察反应条件（壳聚糖质量浓度、温度和时间）对CQDs产物表面官能团和产率的影响,采用TEM、FTIR、XRD、UV-Vis和PL等技术对其形貌、结构和性能进行了表征,并探究其在防伪领域的应用。结果表明,当壳聚糖质量浓度为10 g/L,温度为180 ℃,时间为12 h时,制得的CQDs结构完整且产率较高;微观表现为球状纳米颗粒,直径约为36.2 nm,表面伴有羟基和氨基官能团;制得的CQDs在293和330 nm处均有吸收峰,表现为蓝色荧光,荧光量子产率约为39.8%。将其配制成墨水后,结合喷墨印刷,在自然光和紫外光下可有效实现加密信息的“显”和“隐”,具有较好的防伪效果。     

蓝色荧光碳点的制备及检测、防伪应用

以柠檬酸钠为碳源、氨水为氮源,采用一步水热法制备了氮掺杂碳点(NCDs),对其制备条件进行了优化.采用荧光光谱仪、TEM、AFM、XPS及FTIR对制备的NCDs进行了表征,并探索了NCDs在Fe3+检测及荧光防伪中的应用.结果表明,NCDs的最优制备条件为柠檬酸钠浓度为0.1 mol/L、氨水浓度为1.8 mol/L、反应温度为200℃、反应时间6 h、装载体积25 mL.在最优条件下制备的NCDs的荧光为典型的非激发波长依赖型,最佳激发波长为343 nm,最佳发射波长为443 nm,荧光量子产率可达54.9％.NCDs为球形结构,平均粒径为4.96 nm,碳核为类石墨烯结构且其表面含有—NH2、—OH及—COOH.NCDs的荧光可被Fe3+选择性猝灭,且荧光猝灭程度与Fe3+浓度在0.1～87.5μmol/L范围内线性关系良好,检测限为50 nmol/L.此外,将NCDs配制成荧光墨水,利用喷墨打印机打印出的图案整体饱满、边缘细节清晰具有很强的可识别性.     

生物质碳量子点的制备及应用研究进展

碳量子点（Carbon Quantum Dots,CQDs）是一种新型生物荧光碳纳米材料,具有良好的生物相容性、水溶性、稳定的光电性质、强荧光性、低毒性、易于功能化等优质特性,受到研究者们的广泛关注。其中,采用生物质作为前驱体制备生物质碳量子点过程绿色环保,还可以赋予低价值的生物质废弃物更高的综合利用率。本文综述了生物质碳量子点的制备原料、制备方法以及在细胞成像、离子检测、能量储存等方面的应用。     

碳量子点的制备及其在发光二极管中的应用

碳量子点是纳米材料领域一个备受关注的荧光纳米材料,仅近几年里,基于碳量子点的研究,在制备和应用方面均取得了许多突破性的进展。本文简述了碳量子点的优异特性及其合成方法,重点概述了碳量子点的修饰、复合材料的制备以及在发光二极管(LED)应用方面的最新研究进展。以期为碳量子点的发展应用提供思路和参考。     

酸皮基磷光型碳点的制备及防伪应用

磷光材料凭借其优异的余辉特性、制备简便、低毒性等优点,在光学传感、生物成像、防伪等领域展现出良好的应用前景。制革加工中及皮革制品废弃后会产生大量浸酸山羊皮边角料,浸酸山羊皮已被证明可以用于制备荧光型碳点（CDs）并用于防伪;开发磷光型碳点有望丰富酸皮基碳点的种类并提升防伪效果。本研究以浸酸山羊皮为碳源,硼酸为硼源,采用热解法制备磷光型碳点（P-CDs）。探讨了浸酸山羊皮含量、反应pH、反应温度和反应时间等对P-CDs余辉时长的影响。结果表明当硼酸与浸酸山羊皮的质量比为3：0.12,反应pH为7,反应温度为225 ℃,反应时间为7.5 h时,碳点的余辉时间最长,达到12 s;该材料的发射波长为520 nm,对应明亮的绿色余辉。通过表征发现P-CDs平均粒径为4.42 nm左右,具有典型的石墨结构,硼原子成功的掺入碳点中形成了C-B、B-O等共轭链结构,稳定了三重激发态,延长了余辉时间。该材料在防伪及信息加密领域呈现潜在的应用价值。     

发光碳量子点的合成及应用

碳元素是地球上所有已知生命的基础.由于其具有多样的电子轨道特性(sp、sp2、sp3),因此形成许多结构和性质奇特的物质.碳量子点是2004年发现的一种新型碳材料,相对于传统的半导体量子点和有机染料,这位碳家族中的新成员不仅保持了碳材料毒性     

碳量子点制备及其在环境治理领域应用进展

碳量子点(CQDs)是一种新型的碳纳米材料,具有低毒性、独特的荧光性能以及低成本等特点,在环境治理领域有着广泛的应用.本文重点介绍了介绍了近年来CQDs的不同制备方法,讨论其优缺点,并对于CQDs研究过程中存在的缺陷进行分析,为CQDs的发展提供了思路与建议.     

脱脂棉基碳量子点的制备

以脱脂棉为碳源,采用水热合成法来制备了荧光碳量子点。采用透射电镜、X射线衍射、漫反射光谱、红外光谱对样品的表面形貌、粒径大小、表面基团情况进行表征。结果表明:样品是规则的球形单晶结构,粒径为2.7 nm。     

碳量子点在光催化领域的应用

碳量子点(carbon quantum dots,CQDs)是一种新型的零维碳纳米材料,具有易制备、低毒、生物兼容性好,及良好的光稳定性等特点,在生物成像、传感器及电致发光器件等领域具有潜在的应用前景。除此之外,碳量子点的尺寸依赖性、上转换发光性质、响应波长从近红外区延伸到可见区等优点使其成为太阳能光催化材料领域的"新宠"。就碳量子点在光催化领域的应用进行了综述。     

Preparation of functionalized water-soluble photoluminescent carbon quantum dots from petroleum coke

Here we report a new strategy for preparation of water-soluble photoluminescent carbon quantum dots (CQDs) from petroleum coke. Petroleum coke was oxidized first in mixed concentrated H₂SO₄ and HNO₃, and then functionalized by hydrothermal ammonia treatment. The as-made CQDs and nitrogen-doped CQDs (N-CQDs) were characterized by UV–Vis absorption spectroscope, fluorescence spectroscope, transmission electron microscope, atomic force microscope, Raman spectrometer, X-ray powder diffractometer, X-ray photoelectron spectroscope and Fourier transform infrared spectrometer. The results show that the quantum yield of CQDs increases greatly from 8.7 to 15.8%, and the fluorescent lifetime increases from 3.86 to 6.11 ns after the hydrothermal treatment in ammonia. Moreover, the fluorescent color of N-CQDs can be tuned through the amount of doped nitrogen. Both CQDs and N-CQDs are water-soluble, and have uniform particle distribution, strong luminescence, and highly fluorescent sensitivity to pH in a range of 2.0–12.0. The uniform size distribution and nitrogen-doping of N-CQDs help to lead to high yield of radiative recombination, resulting in improved fluorescence properties. This work offers a simple pathway to produce high quality and enhanced photoluminescent CQDs from petroleum coke.     

微波合成含氮掺杂碳量子点改性水性聚氨酯的制备与性能

以柠檬酸和尿素分别为碳源和氮源,微波法合成含氮掺杂碳点N-CDs。以异氟尔酮二异氰酸酯（IPDI）、聚氧化丙烯（PPG-2000）为主要原料,加入不同量的N-CDs制备一系列碳点水性聚氨酯复合材料 （N-CDs/WPU）。通过FTIR、TEM、XPS、UV-vis、荧光光谱和力学性能测试等对复合材料结构和性能进行表征。测试结果表明N-CDs主要由碳氮氧元素组成,表面具有胺基、羟基等活性基团,N-CDs的加入,提高了复合胶膜的力学性能,赋予了胶膜荧光性能。当N-CDs质量分数为0.6%时胶膜拉伸强度达到最大35.00MPa,加入量质量分数为0.8%时荧光强度最佳。     

半导体纳米晶体制备及应用进展

综述了量子点的制备及应用进展     

Green and continuous microflow synthesis of fluorescent carbon quantum dots for bio-imaging application

In this work, a simple, continuous and completely green method based on microflow technique is demonstrated for the synthesis of carbon quantum dots (CQDs) from diverse bio-based precursors. CQDs prepared from milk is illustrated as a case study to show the process feasibility. Crystalline fluorescent CQDs of 12.53% quantum yield and good stability are synthesized by the approach, even at 120°C. Systematic experiments further suggest their optical properties, bandgap energy, and fluorescence lifetime are closely related to the synthesis temperature. The maximum production rate of the CQDs was 51.1 mg/h at 180°C. Cytotoxicity and cellular imaging tests against 3T3 cells reveal the CQDs possess high biocompatibility, and can penetrate cell membranes and display bright fluorescence. The process versatility is investigated by expanding the precursor to watermelon juice, orange juice, and soy milk, indicating successful synthesis of small-sized CQDs of low cytotoxicity and strong photoluminescence by the technique.     

Preparation and visible light photocatalytic activity of carbon quantum dots/TiO2 nanosheet composites

Carbon quantum dots (C QDs)/TiO₂ nanosheet (TNS) composites were prepared by a simple low temperature process in which TNS were dispersed in C QDs solution, and dried at 60 °C. The C QDs/TNS composites were characterized by X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, transmission electron microscopy (TEM) and high-resolution TEM. The results indicated that C QDs were well combined with TNS through surface carbon–oxygen groups. The photocatalytic activity was investigated by degradation of rhodamine B under visible light irradiation. The photocatalytic activity of C QDs/TNS composites was significantly enhanced compared with that of C QDs/P25 composites and pure TNS, which indicated that the unique up-converted photoluminescence behavior of C QDs and highly reactive {0 0 1} facets of TNS both played important roles in the enhancement of photocatalytic activity of C QDs/TNS composites.     

Polyamine-functionalized carbon quantum dots for chemical sensing

Polyamine-functionalized carbon quantum dots (CQDs) with high fluorescence quantum yield (42.5%) have been synthesized by the low temperature (<200 °C) carbonization of citric acid with branched polyethylenimine (BPEI) in one simple step. The obtained BPEI–CQDs are spherical graphite nanocrystals (average 6.2 nm in size) capped with abundant BPEI at their surfaces. It is the first report that CQDs are both amino-functionalized and highly fluorescent, which suggests their promising applications in chemical sensing.