The regulation of hydrophilicity and hydrophobicity of carbon dots via a one-pot approach

2015 ◽  
Vol 3 (29) ◽  
pp. 6013-6018 ◽  
Author(s):  
Quan-Xing Mao ◽  
Wen-Jing Wang ◽  
Xin Hai ◽  
Yang Shu ◽  
Xu-Wei Chen ◽  
...  

The hydrophilicity or hydrophobicity of carbon dots is regulated by varying the H3PO4/ethanol molar ratio, via a hydrothermal process with 1-butyl-3-methylimidazolium hexafluorophosphate as the carbon source in a H3PO4–ethanol medium.

2021 ◽  
Author(s):  
Wenbing Cao ◽  
Yuhan Wu ◽  
Xin Li ◽  
Xuanfeng Jiang ◽  
Yuhong Zhang ◽  
...  

Abstract Silane-functionalized carbon dots (SiCDs) can be exploited as effective color converting materials for the solid-state light-emitting devices. However, most of SiCDs reported thus far have shown photoluminescence emissions in the blue and green spectral range, which limit them to construct an efficient white light-emitting diodes (WLEDs) due to the lack of long-wavelength emission. Herein, a series of double silane-functionalized carbon dots (DSiCDs) were prepared via a one-step solvothermal method. The results show that the organic functional group of the silane has great influence on the optical properties of DSiCDs and the number of alkoxy group in the silane has great influence on coating properties of DSiCDs. In addition, the DSiCDs prepared by (3-aminopropyl)triethoxysilane and N-[3-(Trimethoxysilyl)propyl]ethylenediamine with molar ratio of 7:3 show excellent optical properties with the maximum emission at 608 nm under 400 nm excitation. Furthermore, they can be completely dried within 1 h at room temperature to form fluorescent coating with high stability and strong adhesion to the substrate. Together with their excellent optical and coating properties, they can be directly coated on LED chips to prepare WLEDs, with a CIE coordinate of (0.33,0.31), color rendering index of 81.6, and color temperature of 5774 K.


2022 ◽  
Vol 19 ◽  
Author(s):  
Gulu Abbasova ◽  
Ajdar Medjidov

Abstract: A one-pot conversion of 2-hydroxy-1-naphthoic aldehyde to hydroxamic acid was described. An efficient photoorganocatalytic method of synthesis was developed. The obtained hydroxamic acid was identified by various physicochemical methods such as IR, UV- and NMR-spectroscopy. Solid colored complexes of copper (II) and iron (II), respectively, green and brown colours with the obtained hydroxamic acid were synthesized in ethanol medium for the first time. The molar ratio of ligand and metal in the complex was 2:1. Their structures were established using IR, UV- spectroscopy and thermogravimetric analysis.


RSC Advances ◽  
2015 ◽  
Vol 5 (115) ◽  
pp. 95223-95229 ◽  
Author(s):  
Xiaoqing Niu ◽  
Guosheng Liu ◽  
Luyao Li ◽  
Zheng Fu ◽  
Hang Xu ◽  
...  

A green, simple and low-cost approach was present to obtain N-doped C-dots using vegetables as the sole carbon source through facile one-pot hydrothermal treatment. The C-dots can serve as a suitable sensing platform for detection of Cu2+.


RSC Advances ◽  
2019 ◽  
Vol 9 (38) ◽  
pp. 21715-21723 ◽  
Author(s):  
Guili Wei ◽  
Ziqiang Zhao ◽  
Jie Du ◽  
Pan Li ◽  
Zhuxing Sun ◽  
...  

A highly selective and sensitive fluorescent probe for detecting Fe3+, carbon dots (CDs), was prepared with renewable reed naturally containing C, N, O, and S elements as a green and eco-friendly carbon source by a simple hydrothermal process.


RSC Advances ◽  
2019 ◽  
Vol 9 (15) ◽  
pp. 8290-8299 ◽  
Author(s):  
Dandan Xu ◽  
Fang Lei ◽  
Haohong Chen ◽  
Luqiao Yin ◽  
Ying Shi ◽  
...  

Blue CDs with a quantum yield of 30.21% were successfully synthesized by a simple one-pot hydrothermal treatment using citric acid (carbon source) and polyvinyl pyrrolidone (nitrogen source) as the raw materials towards fluorescent ink and as nanosensors for Fe3+ detection.


2021 ◽  
Author(s):  
Yuanyuan Hu ◽  
Wenxuan Ji ◽  
Jinjuan Qiao ◽  
Heng Li ◽  
Yun Zhang ◽  
...  

Abstract Although carbon dots (CDs) as fluorescent sensors have been widely exploited, multi-component detection using CDs without tedious surface modification is always a challenging task. Here, two kinds of nitrogen-doped CDs (NCD-m and NCD-o) based on soluble starch (SS) as carbon source were prepared through one-pot hydrothermal process using m-phenylenediamine and o-phenylenediamine as nitrogenous dopant respectively. Through fluorescence “on-off” mechanism of CDs, NCD-m and NCD-o could be used as a fluorescence sensor for detection of Fe 3+ and Ag + with LOD of 0.25 and 0.5 μM, respectively. Additionally, NCD-m could be used for indirect detection of ascorbic acid (AA) with LOD of 5 μM. Moreover, fluorescence intensity of NCD-m also exhibited the sensitivity to pH change from 2 to 13. More importantly, Both NCD-m and NCD-o had potential application for analysis of complicated real samples such as tap water, Vitamin C tablets and orange juice. Ultimately, the small size of NCD-m could contribute to reinforcing intracellular endocytosis, which allowed them to be used for bacteria imaging.


2020 ◽  
Vol 16 ◽  
Author(s):  
Pan Zhang ◽  
Shun-Sheng Zhao ◽  
JiaJia Wang ◽  
Xiang Rong Liu

Background: In recent years, environmental pollution and heavy metal pollution caused by rapid urbanization and industrialization have become increasingly serious. Among them, mercury (II) ion (Hg2+) is one of the highly toxic heavy metal ions, and its pollution comes from various natural resources and human activities. Therefore, people attach great importance to the development of analytical methods for effective analysis and sensitive detection of Hg2+ . Objective: Using grape skin as a green and environmental friendly carbon source, to synthesize fluorescent carbon dots, and try to apply them to the detect the concentration of Hg2+ in water. Method: Using "Hutai No. 8" grape skin as carbon source, fluorescent carbon dots were synthesized by one-step hydrothermal method. Structure and fluorescent properties of the carbon dots were tested using TEM, XPS, XRD and other characterization instruments, and their utilization on detection of mercury ions in the actual water samples was explored. Results: The CDs had a particle size of about 4.8 nm and a spherical shape. There are N-H, C-N, C=O and other functional groups on the surface. It was found that Hg2+ has obvious fluorescence quenching effect on CDs, and thus CDs fluorescence quenching method to detect the concentration Hg2+ was established, and the detection limit is 3.7 μM, which could be applied to test the concentration of Hg2+ in water samples. Conclusion: Using grape skin as carbon source, fluorescent carbon dots were successfully synthesized by hydrothermal method. Carbon dots were used to detect mercury ions in water, and a method for detecting mercury ions in actual water samples was established.


2021 ◽  
Vol 11 (4) ◽  
pp. 1630
Author(s):  
Yakubu Newman Monday ◽  
Jaafar Abdullah ◽  
Nor Azah Yusof ◽  
Suraya Abdul Rashid ◽  
Rafidah Hanim Shueb

Carbon dots (CDs), a nanomaterial synthesized from organic precursors rich in carbon content with excellent fluorescent property, are in high demand for many purposes, including sensing and biosensing applications. This research focused on preparing CDs from natural and abundant waste, palm kernel shells (PKS) obtained from palm oil biomass, aiming for sensing and biosensing applications. Ethylenediamine and L-phenylalanine doped CDs were produced via the hydrothermal and solvothermal methods using one-pot synthesis techniques in an autoclave batch reactor. The as-prepared N-CDs shows excellent photoluminescence (PL) property and a quantum yield (QY) of 13.7% for ethylenediamine (EDA) doped N-CDs (CDs-EDA) and 8.6% for L-phenylalanine (L-Ph) doped N-CDs (CDs-LPh) with an excitation/emission wavelength of 360 nm/450 nm. The transmission electron microscopy (TEM) images show the N-CDs have an average particle size of 2 nm for both CDs. UV-Visible spectrophotometric results showed C=C and C=O transition. FTIR results show and confirm the presence of functional groups, such as -OH, -C=O, -NH2 on the N-CDs, and the X-ray diffraction pattern showed that the N-CDs were crystalline, depicted with sharp peaks. This research work demonstrated that palm kernel shell biomass often thrown away as waste can produce CDs with excellent physicochemical properties.


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