scholarly journals Green Synthesis of Carbon Dots from Grapefruit and Its Fluorescence Enhancement

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Xinzhu Huo ◽  
Yuxuan He ◽  
Shiqi Ma ◽  
Yingying Jia ◽  
Jiaming Yu ◽  
...  

In this study, undoped carbon quantum dots (UCQDs, UCQDs-peel) and N-doped carbon dots (NCQDs) were prepared by a facile one-pot environmentally friendly hydrothermal method using grapefruit as carbon sources in the absence and presence of area, respectively. The structure, morphology, and fluorescence properties of three samples were characterized by Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), and photoluminescence (PL). It was found that three types of CQDs could emit blue fluorescence with different intensities when irradiated with ultraviolet light. Compared to the luminescence properties of UCQDs, NCQDs, and UCQDs-peel, it can be seen that the fluorescence intensity of NCQDs was strongest due to the presence of NH and C-N bonds.

2021 ◽  
Author(s):  
Deepak Totaram Tayde ◽  
Madhukar E. Navgire ◽  
Machhindra K. Lande

Abstract A convenient, One pot synthesis of heterocyclic nucleous acridine derivative compound has been achieved those are having very much attention in medicinal chemistry because of their extensive application in biology. The mixture of dimedone, substituted benzaldehyde and aniline were catalyzed by efficient In2O3-SiO2 heterogeneous reusable catalyst in ethanol to obtain the desired acridine derivatives with good yield. Hydrothermal method used to synthesize In2O3-SiO2 catalytic material. This catalytic material were characterized by using X-ray diffraction spectroscopy (XRD), scanning electron microscopy (SEM), Energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FT-IR), Transmission electron microscope (TEM), Temperature-programmed desorption (NH3-TPD) and Brunauer-Emmett-Teller (BET). Our synthetic strategy features high yield, simple work up procedure, non-toxic, clean, and easy recovery and reusability of the catalytic system.


RSC Advances ◽  
2021 ◽  
Vol 11 (54) ◽  
pp. 34107-34116
Author(s):  
Jiawei Li ◽  
Ouwen Xu ◽  
Xiashi Zhu

In this study, an on–off–on fluorescence probe for the detection of trace Cu(ii) and ascorbic acid (AA) based on biomass-derived sulfur and nitrogen double heteroatom-doped carbon dots (N,S-CDs) was designed.


Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 456
Author(s):  
Fahad A. Alharthi ◽  
Hamdah S. Alanazi ◽  
Amjad Abdullah Alsyahi ◽  
Naushad Ahmad

This study demonstrated the hydrothermal synthesis of bimetallic nickel-cobalt tungstate nanostructures, Ni-CoWO4 (NCW-NPs), and their phase structure, morphology, porosity, and optical properties were examined using X-ray Diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), Scanning electron microscopy- energy dispersive X-ray spectroscopy (SEM-EDS), high resolution Transmission electron microscopy (HR-TEM), Brunauer-Emmett-Teller (BET) and Raman instruments. It was found that as-calcined NCW-NPs have a monoclinic phase with crystal size ~50–60 nm and is mesoporous. It possessed smooth, spherical, and cubic shape microstructures with defined fringe distance (~0.342 nm). The photocatalytic degradation of methylene blue (MB) and rose bengal (RB) dye in the presence of NCW-NPs was evaluated, and about 49.85% of MB in 150 min and 92.28% of RB in 90 min degraded under visible light. In addition, based on the scavenger’s study, the mechanism for photocatalytic reactions is proposed.


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.


2019 ◽  
Vol 11 (4) ◽  
pp. 490-506 ◽  
Author(s):  
K. Radhakrishnan ◽  
P. Panneerselvam ◽  
M. Marieeswaran

In this work, a green synthetic route was used to create a number of surface passivated fluorescent carbon quantum dots, which are explored as promising sensing probes, via facile one-pot hydrothermal methods.


2011 ◽  
Vol 194-196 ◽  
pp. 594-597
Author(s):  
Ke Tang ◽  
Xin Hong ◽  
Jin Gang Qi

FAU-type(NaY) zeolites nanocrystals have been synthesized through crystallization of gel in mesoporous system of carbon nanotubes(CNTS) with a internal diameter of 20~30 nm. Investigation by using X-ray diffraction (XRD), Fourier transform infrared (FT-IR), transmission electron microscope (TEM) shows that the nanocrystals possess the typical nanosized zeolites structural characteristics which is different from those of microsized zeolites.


2019 ◽  
Vol 11 (20) ◽  
pp. 2650-2657 ◽  
Author(s):  
Yifang Gao ◽  
Huilin Zhang ◽  
Shaomin Shuang ◽  
Hui Han ◽  
Chuan Dong

Novel nitrogen co-doped carbon dots (NCDs) were synthesized as a fluorescent “on–off–on” switch for the highly sensitive and selective sensing of Cu2+ and glutathione (GSH) by a straightforward pyrolysis route.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Tiedan Chen ◽  
Yanqiu Xia ◽  
Zhengfeng Jia ◽  
Zhilu Liu ◽  
Haobo Zhang

Graphene oxide (GO) nanosheets were prepared by modified Hummers and Offeman methods. Furthermore, oleic acid (OA) capped graphene oxide (OACGO) nanosheets were prepared and characterized by means of Fourier transform-infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), and X-ray diffraction (XRD). At the same time, the friction and wear properties of OA capped graphite powder (OACG), OACGO, and oleic acid capped precipitate of graphite (OACPG) as additives in poly-alpha-olefin (PAO) were compared using four-ball tester and SRV-1 reciprocating ball-on-disc friction and wear tester. By the addition of OACGO to PAO, the antiwear ability was improved and the friction coefficient was decreased. Also, the tribological mechanism of the GO was investigated.


2020 ◽  
Vol 10 (11) ◽  
pp. 1777-1787
Author(s):  
Yadian Xie ◽  
Shanshan Wang ◽  
Ning Fu ◽  
Yan Yang ◽  
Xingliang Liu ◽  
...  

Carbon dots (CDs) also nitrogen-doped CDs (N-CDs) were produced by green hydrothermal synthesis using Pea and ethanediamine as the carbon and nitrogen source, separately. Transmission electron microscopy (TEM) images displayed that the prepared CDs and N-CDs were well dispersed, had a spherical morphology. X-ray diffraction (XRD) figures of CDs and N-CDs presented a graphitic amorphous structure. Fourier transform infrared spectroscopy (FT-IR) verified that CDs and N-CDs carried many different hydrophilic groups (for example hydroxyl, carboxyl/carbonyl, amide, amino groups) on the surface, X-ray photoelectron spectroscopy (XPS) together verified this result. However, the optical properties and fluorescence quantum yield for N-CDs were obviously superior to those of CDs. Furthermore, the prepared N-CDs displayed outstanding advantages including low toxicity, satisfactory biocompatibility, and excellent chemical stability. More prominently, the prepared N-CDs could detect Hg2+ ions with high sensitivity and selectivity in both water samples and HeLa cells.


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