scholarly journals Fast, energy-efficient synthesis of luminescent carbon quantum dots

2014 ◽  
Vol 16 (5) ◽  
pp. 2566-2570 ◽  
Author(s):  
Yongsheng Li ◽  
Xiaoxia Zhong ◽  
Amanda E. Rider ◽  
Scott A. Furman ◽  
Kostya (Ken) Ostrikov
Keyword(s):  
Quantum Dots ◽  
Energy Efficient ◽  
Synthesis Method ◽  
Carbon Quantum Dots ◽  
Efficient Synthesis ◽  
Carbon Dot

A simple, fast, energy and labour efficient, carbon dot synthesis method involving only the mixing of a saccharide and base is presented.

scholarly journals Formation of Carbon Quantum Dots via Hydrothermal Carbonization: Investigate the Effect of Precursors

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 986
Author(s):  
Md Rifat Hasan ◽  
Nepu Saha ◽  
Thomas Quaid ◽  
M. Toufiq Reza
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Microcrystalline Cellulose ◽  
Uv Light ◽  
Synthesis Method ◽  
Hydrothermal Carbonization ◽  
Carbon Quantum Dots ◽  
Medical Diagnostics ◽  
Particle Size Range ◽  
Wide Range

Carbon quantum dots (CQDs) are nanomaterials with a particle size range of 2 to 10 nm. CQDs have a wide range of applications such as medical diagnostics, bio-imaging, biosensors, coatings, solar cells, and photocatalysis. Although the effect of various experimental parameters, such as the synthesis method, reaction time, etc., have been investigated, the effect of different feedstocks on CQDs has not been studied yet. In this study, CQDs were synthesized from hydroxymethylfurfural, furfural, and microcrystalline cellulose via hydrothermal carbonization at 220 °C for 30 min of residence time. The produced CQDs showed green luminescence behavior under the short-wavelength UV light. Furthermore, the optical properties of CQDs were investigated using ultraviolet-visible spectroscopy and emission spectrophotometer, while the morphology and chemical bonds of CQDs were investigated using transmission electron microscopy and Fourier-transform infrared spectroscopy, respectively. Results showed that all CQDs produced from various precursors have absorption and emission properties but these optical properties are highly dependent on the type of precursor. For instance, the mean particle sizes were 6.36 ± 0.54, 5.35 ± 0.56, and 3.94 ± 0.60 nm for the synthesized CQDs from microcrystalline cellulose, hydroxymethylfurfural, and furfural, respectively, which appeared to have similar trends in emission intensities. In addition, the synthesized CQDs experienced different functionality (e.g., C=O, O-H, C-O) resulting in different absorption behavior.

Enhancement of visible-light-driven photoresponse of Mn-doped SnO 2 quantum dots obtained by rapid and energy efficient synthesis

2018 ◽  
Vol 195 ◽  
pp. 283-289 ◽  
Author(s):  
B. Babu ◽  
A.N. Kadam ◽  
G. Thirumala Rao ◽  
Sang-Wha Lee ◽  
Chan Byon ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Visible Light ◽  
Energy Efficient ◽  
Efficient Synthesis ◽  
Visible Light Driven ◽  
Mn Doped

Green and efficient synthesis of carbon quantum dots and their luminescent properties

2019 ◽  
Vol 206 ◽  
pp. 158-163 ◽  
Author(s):  
Langfeng Zhou ◽  
Meng Qiao ◽  
Lei Zhang ◽  
Lu Sun ◽  
Yang Zhang ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Luminescent Properties ◽  
Carbon Quantum Dots ◽  
Efficient Synthesis

scholarly journals Recent Advancements in Doped/Co-Doped Carbon Quantum Dots for Multi-Potential Applications

2019 ◽  
Vol 5 (2) ◽  
pp. 24 ◽  
Author(s):  
Ganeshlenin Kandasamy
Keyword(s):  
Quantum Dots ◽  
Optical Sensors ◽  
Carbon Nanomaterials ◽  
Synthesis Method ◽  
Carbon Quantum Dots ◽  
Carbon Nanodots ◽  
Synthesis Methods ◽  
Sensing Applications ◽  
Potential Applications ◽  
Co Doped

Carbon quantum dots (CQDs)/carbon nanodots are a new class of fluorescent carbon nanomaterials having an approximate size in the range of 2–10 nm. The majority of the reported review articles have discussed about the development of the CQDs (via simple and cost-effective synthesis methods) for use in bio-imaging and chemical-/biological-sensing applications. However, there is a severe lack of consolidated studies on the recently developed CQDs (especially doped/co-doped) that are utilized in different areas of application. Hence, in this review, we have extensively discussed about the recent development in doped and co-doped CQDs (using elements/heteroatoms—e.g., boron (B), fluorine (F), nitrogen (N), sulphur (S), and phosphorous (P)), along with their synthesis method, reaction conditions, and/or quantum yield (QY), and their emerging multi-potential applications including electrical/electronics (such as light emitting diode (LED) and solar cells), fluorescent ink for anti-counterfeiting, optical sensors (for detection of metal ions, drugs, and pesticides/fungicides), gene delivery, and temperature probing.

Photocatalytic Activity of Phosphorus and Nitrogen Co-Doped Carbon Quantum Dots/TiO2 Nanosheets

NANO ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. 2050151
Author(s):  
Kailai Liu ◽  
Fanmin Kong ◽  
Chaoqun Zhu ◽  
Guodong Jiang
Keyword(s):  
Quantum Dots ◽  
Quantum Wells ◽  
Uv Light ◽  
Kinetic Constant ◽  
Synthesis Method ◽  
Carbon Quantum Dots ◽  
Active Species ◽  
Doping Amount ◽  
Tio2 Nanosheets ◽  
Co Doped

Double element co-doped carbon quantum dots (CQDs) have unique electron properties and broad prospects in photocatalysis. In this paper, the phosphorus and nitrogen co-doped CQDs (PNCQDs) were loaded on TiO2 nanosheets by in-situ synthesis method. Physical structure and chemical composition of samples were analyzed by XRD, FT-IR, XPS, SEM and TEM. UV–Vis spectra show the donor–acceptor coupling between PNCQDs and TiO2 and enhanced strong UV light absorption. Photoluminescence spectra indicate that PNCQDs effectively promote charge separation, which is different from nitrogen doped CQDs. The sample 1-PNCT with the optimal phosphorus doping amount has the highest kinetic constant for photodegradation of Methylene Blue (MB), which is 3.4 times pure TiO2. A possible Z-scheme photodegradation mechanism is proposed according to the active species scavenge experiment results in which PNCQDs can not only accept but also localize photogenerated electrons to dopant sites due to the quantum wells created by P and N doping energy barriers.

scholarly journals Carbon Dots for Sensing and Killing Microorganisms

2019 ◽  
Vol 5 (2) ◽  
pp. 33 ◽  
Author(s):  
Fengming Lin ◽  
Yan-Wen Bao ◽  
Fu-Gen Wu
Keyword(s):  
Quantum Dots ◽  
Carbon Dots ◽  
Carbon Nanoparticles ◽  
Surface Passivation ◽  
Electronic Devices ◽  
Carbon Quantum Dots ◽  
Toxicity Profile ◽  
Carbon Dot ◽  
Underlying Mechanisms

Carbon dots (or carbon quantum dots) are small (less than 10 nm) and luminescent carbon nanoparticles with some form of surface passivation. As an emerging class of nanomaterials, carbon dots have found wide applications in medicine, bioimaging, sensing, electronic devices, and catalysis. In this review, we focus on the recent advancements of carbon dots for sensing and killing microorganisms, including bacteria, fungi, and viruses. Synthesis, functionalization, and a toxicity profile of these carbon dots are presented. We also discuss the underlying mechanisms of carbon dot-based sensing and killing of microorganisms.

High and reversible oxygen uptake in carbon dot solutions generated from polyethylene facilitating reactant-enhanced solar light harvesting

Nanoscale ◽  
2020 ◽  
Vol 12 (19) ◽  
pp. 10480-10490
Author(s):  
Sanjit Mondal ◽  
Pitchiah E. Karthik ◽  
Lipipuspa Sahoo ◽  
Kaustav Chatterjee ◽  
M. Sathish ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Oxygen Uptake ◽  
Light Harvesting ◽  
Carbon Quantum Dots ◽  
Oxygen Enrichment ◽  
Solar Light ◽  
Oxidation Reactions ◽  
Carbon Dot ◽  
Photo Oxidation

Carbon quantum dots obtained from polyethylene exhibit large oxygen enrichment properties in solution enabling catalytic photo-oxidation reactions without artificial oxygen enrichment.

A sandwich-type ECL immunosensor for sensitive determination of CEA content based on red emission carbon quantum dots as luminophores

2021 ◽  
Author(s):  
Yuefang Hu ◽  
Yuxin Chen ◽  
Quan Tang ◽  
Hanfu Liu
Keyword(s):  
Quantum Dots ◽  
Microwave Synthesis ◽  
Synthesis Method ◽  
Carbon Quantum Dots ◽  
Single Step ◽  
Red Emission ◽  
Sandwich Type ◽  
Sensitive Determination

A sandwich-type electrochemiluminescence (ECL) immunosensor was constructed using red-emitting carbon quantum dots (RCQDs) as luminophores. The RCQDs were prepared in a single step by the simple green microwave synthesis method...

Synthesis of green-emitting carbon quantum dots with excitation wavelength dependent photoluminescence obtained from aqueous beetroot extract

MRS Advances ◽  
2016 ◽  
Vol 1 (19) ◽  
pp. 1371-1376 ◽  
Author(s):  
George R. S. Andrade ◽  
Silvânio S. L. Costa ◽  
Cristiane C. Nascimento ◽  
Iara F. Gimenez
Keyword(s):  
Quantum Dots ◽  
Carbon Source ◽  
Energy Efficient ◽  
Emission Spectra ◽  
Carbon Quantum Dots ◽  
Excitation Wavelength ◽  
Photoluminescence Properties ◽  
Microwave Assisted ◽  
Band Position ◽  
The One

ABSTRACTIn this work, 3 simple, fast, labour and energy efficient methodologies were used to prepare carbon quantum dots (C-dots) using a red beetroot (Beta vulgaris subsp. vulgaris var. vulgaris) aqueous extract as the carbon source: alkali-assisted (AA), microwave-assisted (MA) and alkali-microwave-assisted (AMA) synthesis. TEM images shows nanoparticles with a nearly spherical morphology and diameters around 7.0 nm. FTIR spectra show characteristic peaks of C-H, C-O, O-H and C=C bonds for all the samples. The emission spectra show an interesting feature of the as-prepared samples: the emission band position can be tunable by changing the excitation wavelength. Comparing the 3 different methodologies in terms of photoluminescence properties, the one based only on the microwave-assisted heating has showed the most improved emission.

scholarly journals Economical, Green Synthesis of Fluorescent Carbon Quantum Dots from Lac Extract

2020 ◽  
Vol 5 (3) ◽  
pp. 213-217 ◽  
Keyword(s):  
Quantum Dots ◽  
Green Synthesis ◽  
Water Solubility ◽  
Low Cost ◽  
Hydrothermal Process ◽  
Synthesis Method ◽  
Photovoltaic Cell ◽  
Carbon Quantum Dots ◽  
Sensor Applications ◽  
Fluorescent Carbon

Fluorescent carbon quantum dots (FCDs) have attracted tremendous interest because of their advantageous characteristics of cost effectiveness and fluorescent nature. In this study, we developed a simple, economical and effective method for the green synthesis of fluorescent carbon quantum dots (FCDs) from Lac of Butea monosperma host tree, a renewable and sustainable resource. The synthesis method involves the low cost hydrothermal process using the Lac extract as a carbon source. The as-synthesized FCDs were characterized by Xray diffraction (XRD), Transmission electron microscopy (TEM) and Spectrofluorophotometer. The synthesized FCDs possess stable good water solubility as well as high quantum yield. The results suggest that the proposed FCDs could be utilized for photovoltaic cell, bio imaging, drug delivery and bio-sensor applications.

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