scholarly journals Evaluation of the Environmental Impact and Efficiency of N-Doping Strategies in the Synthesis of Carbon Dots

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 504 ◽  
Author(s):  
Christé ◽  
Esteves da Silva ◽  
Pinto da Silva
Keyword(s):  
Carbon Dots ◽  
Organic Molecules ◽  
Blue Emission ◽  
Xps Analysis ◽  
Small Organic Molecules ◽  
Microwave Assisted ◽  
N Doping ◽  
Synthesis Routes ◽  
The One ◽  
Synthesis Yield

The efficiency and associated environmental impacts of different N-doping strategies of carbon dots (CDs) were evaluated. More specifically, N-doped CDs were prepared from citric acid via two main synthesis routes: Microwave-assisted hydrothermal treatment with addition of N-containing small organic molecules (urea and ethylenediamine (EDA)); and microwave-assisted solvothermal treatment in N-containing organic solvents (n,n-dimethylformamide (DMF), acetonitrile and pyridine). These syntheses produced CDs with similar blue emission. However, XPS analysis revealed that CDs synthesized via both hydrothermal routes presented a better N-doping efficiency (~15 at.%) than all three solvothermal-based strategies (0.6–7 at.%). However, from the former two hydrothermal strategies, only the one involving EDA as a nitrogen-source provided a non-negligible synthesis yield, which indicates that this should be the preferred strategy. This conclusion was supported by a subsequent life cycle assessment (LCA) study, which revealed that this strategy is clearly the most sustainable one from all five studied synthesis routes.

Fluorescent Carbon Dots and their Applications in Sensing of Small Organic Molecules

2021 ◽  
Vol 17 ◽  
Author(s):  
Sakib Hussain Laghari ◽  
Najma Memon ◽  
Muhammad Yar Khuhawer ◽  
Taj Muhammad Jahangir
Keyword(s):  
Small Molecules ◽  
Fluorescent Probes ◽  
Carbon Dots ◽  
Organic Molecules ◽  
Fluorescent Properties ◽  
Small Organic Molecules ◽  
Uv Visible ◽  
Size Of Particles ◽  
Fluorescent Carbon Dots ◽  
Fluorescent Carbon

Background: Fluorescence-based sensing is considered highly sensitive and fluorescent probes with improved properties are always desired. Fluorescent carbon dots (CDs) are newly emerging quasi-spherical nanoparticles of less than 10 nm in size and belong to the carbon nano-material’s family. CDs have great potential as fluorescent probes and currently are under open deliberation by the researchers due to their striking properties such as low environmental hazard, high selectivity, greater sensitivity, good biocompatibility, tunable fluorescent properties and excitation dependent multicolor emission behavior. Introduction: This review demonstrates various available methods for fabrication of fluorescent CDs, capping of CDs and characterization with various techniques including UV-visible, FT-IR, and TEM. Analytical applications using CDs for the sensing of small organic molecules, specifically nitroaromatic compounds in the environmental samples are complied. Methods: The review covers literature related to synthesis and characterization of carbon dots. It includes around 171 research articles in this field. Results: Carbon dots can be synthesized using numerous routes. In all cases CDs possess spectral properties with little variation in wavelength maxima. Optical properties of CDs can be tuned by compositing these with metallic quantum dots or by modifying their surface with desired functionalities. HR-TEM is needed to see the morphology and size of particles whereas UV-Visible and FTIR are indispensable tools for this kind of research. These particles are successfully applied to sense small molecules in some matrices. Conclusion: Carbon dots are bright stars in fluorescent sensing of small molecules. However, more research is needed to determine small organic molecules in diversified areas of analysis.

scholarly journals N-Doped Carbon Dots Derived from Melamine and Triethanolamine for Selective Sensing of Fe3+ Ions

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Sathishkumar Munusamy ◽  
Sathish Sawminathan ◽  
Thanigaivelan Arumugham ◽  
Maura Casales Díaz ◽  
Srinivas Godavarthi ◽  
...  
Keyword(s):  
Water Samples ◽  
Carbon Dots ◽  
Limit Of Detection ◽  
Blue Emission ◽  
World Health ◽  
Selective Determination ◽  
N Doping ◽  
Health Organization ◽  
Doped Carbon Dots ◽  
Nitrogen Doped Carbon

This work reports nitrogen-doped carbon dots (NCDs) as a selective sensing probe to detect Fe3+ in water samples. NCD probes were synthesized via solvothermal method using nitrogen-rich melamine and triethanolamine as precursors. Properties of the resulting NCDs were studied using different characterization techniques, through which N-doping was confirmed. The quantum yield of obtained NCDs was measured to be 21%. When excited at 370 nm, the excellent blue emission property makes this probe adoptable for selectively sensing Fe3+ in practical water samples. The limit of detection (LOD) was identified as 216 nM with a good linear range between the concentrations of 0.2-2 μM. The obtained LOD is far less than the World Health Organization (WHO) permissible limits of Fe3+ in water. Interference studies reveal that the presence of other competing ions did not alter the sensing of Fe3+, even at the presence of 10 equivalents which indicates the high selectivity of NCDs towards Fe3+. The reversibility studies showed that adding a cheap and readily available EDTA ligand to the NCD results in fluorescence regeneration, leading to exceptional reusability for the detection of Fe3+. So, the synthesized NCDs can be used as a suitable probe for the selective determination of Fe3+ in real water samples.

Ionic liquid-assisted thermal decomposition synthesis of carbon dots and graphene-like carbon sheets for optoelectronic application

RSC Advances ◽  
2016 ◽  
Vol 6 (66) ◽  
pp. 61292-61300 ◽  
Author(s):  
Jia-Yun Wan ◽  
Ze Yang ◽  
Zhong-Guo Liu ◽  
Hang-Xing Wang
Keyword(s):  
Thermal Decomposition ◽  
Ionic Liquid ◽  
Liquid Phase ◽  
Carbon Dots ◽  
Organic Molecules ◽  
Small Organic Molecules ◽  
Optoelectronic Application ◽  
Process Route

A facile process route for the synthesis of carbon dots and graphene-like carbon sheets is reported, which relies on direct carbonization of small organic molecules in a liquid-phase by using ionic liquid as solvent.

scholarly journals Snapshots into carbon dots formation through a combined spectroscopic approach

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Francesco Rigodanza ◽  
Max Burian ◽  
Francesca Arcudi ◽  
Luka Đorđević ◽  
Heinz Amenitsch ◽  
...  
Keyword(s):  
Carbon Dots ◽  
Ad Hoc ◽  
Organic Molecules ◽  
Dense Core ◽  
Carbon Nanodots ◽  
Small Organic Molecules ◽  
The Core ◽  
Ligand Shell ◽  
Shell Design ◽  
Electron Dense Core

AbstractThe design of novel carbon dots with ad hoc properties requires a comprehensive understanding of their formation mechanism, which is a complex task considering the number of variables involved, such as reaction time, structure of precursors or synthetic protocol employed. Herein, we systematically investigated the formation of carbon nanodots by tracking structural, chemical and photophysical features during the hydrothermal synthesis. We demonstrate that the formation of carbon nanodots consists of 4 consecutive steps: (i) aggregation of small organic molecules, (ii) formation of a dense core with an extended shell, (iii) collapse of the shell and (iv) aromatization of the core. In addition, we provide examples of routes towards tuning the core-shell design, synthesizing five novel carbon dots that all consist of an electron-dense core covered by an amine rich ligand shell.

A facile approach for the synthesis of highly luminescent carbon dots using vitamin-based small organic molecules with benzene ring structure as precursors

RSC Advances ◽  
2015 ◽  
Vol 5 (110) ◽  
pp. 90245-90254 ◽  
Author(s):  
Yawen Zheng ◽  
Dan Yang ◽  
Xin Wu ◽  
Haoran Yan ◽  
Yuancong Zhao ◽  
...  
Keyword(s):  
Benzene Ring ◽  
Carbon Dots ◽  
Organic Molecules ◽  
Ring Structure ◽  
Small Organic Molecules ◽  
Hydrothermal Approach

In this study, vitamin-based small organic molecules were used as precursors to synthesize carbon dots by means of a hydrothermal approach.

QUBEKit: Automating the Derivation of Force Field Parameters from Quantum Mechanics

2019 ◽  
Author(s):  
Joshua Horton ◽  
Alice Allen ◽  
Leela Dodda ◽  
Daniel Cole
Keyword(s):  
Quantum Mechanics ◽  
Force Field ◽  
Organic Molecules ◽  
Force Fields ◽  
Liquid Density ◽  
Small Organic Molecules ◽  
Automated Generation ◽  
Energy Of Hydration ◽  
Novel Method ◽  
Force Field Parameters

<div><div><div><p>Modern molecular mechanics force fields are widely used for modelling the dynamics and interactions of small organic molecules using libraries of transferable force field parameters. For molecules outside the training set, parameters may be missing or inaccurate, and in these cases, it may be preferable to derive molecule-specific parameters. Here we present an intuitive parameter derivation toolkit, QUBEKit (QUantum mechanical BEspoke Kit), which enables the automated generation of system-specific small molecule force field parameters directly from quantum mechanics. QUBEKit is written in python and combines the latest QM parameter derivation methodologies with a novel method for deriving the positions and charges of off-center virtual sites. As a proof of concept, we have re-derived a complete set of parameters for 109 small organic molecules, and assessed the accuracy by comparing computed liquid properties with experiment. QUBEKit gives highly competitive results when compared to standard transferable force fields, with mean unsigned errors of 0.024 g/cm3, 0.79 kcal/mol and 1.17 kcal/mol for the liquid density, heat of vaporization and free energy of hydration respectively. This indicates that the derived parameters are suitable for molecular modelling applications, including computer-aided drug design.</p></div></div></div>

QUBEKit: Automating the Derivation of Force Field Parameters from Quantum Mechanics

2019 ◽  
Author(s):  
Joshua Horton ◽  
Alice Allen ◽  
Leela Dodda ◽  
Daniel Cole
Keyword(s):  
Quantum Mechanics ◽  
Force Field ◽  
Organic Molecules ◽  
Force Fields ◽  
Liquid Density ◽  
Small Organic Molecules ◽  
Automated Generation ◽  
Energy Of Hydration ◽  
Novel Method ◽  
Force Field Parameters

<div><div><div><p>Modern molecular mechanics force fields are widely used for modelling the dynamics and interactions of small organic molecules using libraries of transferable force field parameters. For molecules outside the training set, parameters may be missing or inaccurate, and in these cases, it may be preferable to derive molecule-specific parameters. Here we present an intuitive parameter derivation toolkit, QUBEKit (QUantum mechanical BEspoke Kit), which enables the automated generation of system-specific small molecule force field parameters directly from quantum mechanics. QUBEKit is written in python and combines the latest QM parameter derivation methodologies with a novel method for deriving the positions and charges of off-center virtual sites. As a proof of concept, we have re-derived a complete set of parameters for 109 small organic molecules, and assessed the accuracy by comparing computed liquid properties with experiment. QUBEKit gives highly competitive results when compared to standard transferable force fields, with mean unsigned errors of 0.024 g/cm3, 0.79 kcal/mol and 1.17 kcal/mol for the liquid density, heat of vaporization and free energy of hydration respectively. This indicates that the derived parameters are suitable for molecular modelling applications, including computer-aided drug design.</p></div></div></div>

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