scholarly journals The Effect of Amino-functionalization on Photoluminescence Properties of Sugarcane Bagasse-derived Carbon Quantum Dots

2021 ◽  
Vol 21 (1) ◽  
pp. 62
Author(s):  
Muhammad Wahyu Nugraha ◽  
Nonni Soraya Sambudi ◽  
Laksmi Dewi Kasmiarno ◽  
Norashikin Ahmad Kamal
Keyword(s):  
Quantum Dots ◽  
Particle Size ◽  
Sugarcane Bagasse ◽  
Low Cost ◽  
Carbon Quantum Dots ◽  
Photoluminescence Intensity ◽  
One Pot ◽  
Transmission Electron ◽  
Amino Functionalization ◽  
Natural Carbon

In the present study, amino-functionalized carbon quantum dots (N-CQDs) were prepared from sugarcane bagasse using a simple one-pot hydrothermal method. Both ethylenedinitrilotetraacetic (EDTA) & ethylenediamine (EDA) were used as carbon and amino sources, respectively. The emerging utilization of natural carbon precursors is critically essential considering its low cost, eco-friendly, and unexploited by-products (e.g., sugarcane bagasse), which may have sustainable economic and strategic benefits. The as-prepared N-CQDs were characterized using High-Resolution Transmission Electron Microscope (HRTEM), Fourier Transform Infrared Spectroscopy (FTIR), UV-vis absorption spectroscopy, and photoluminescence spectroscopy. The influences of amine groups were investigated. The as-prepared N-CQDs photoluminescence intensity increased and quenched significantly with EDTA and EDA amino-functionalization, respectively, with the highest quantum yield at 21.21%, 2.4 times higher than non-functionalized CQDs. Furthermore, the amino-functional groups can alter the CQDs structure and particle size ranging from 4.197±1.058 nm to 9.704±1.428 nm. Hence, the N-CQDs produced exhibit highly tunable photoluminescence and particle size potentially applicable in diverse applications.

scholarly journals Formation of ZnO/Zn0.5Cd0.5Se Alloy Quantum Dots in the Presence of High Oleylamine Contents

Nanomaterials ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 999
Author(s):  
Yi-An Chen ◽  
Kuo-Hsien Chou ◽  
Yi-Yang Kuo ◽  
Cheng-Ye Wu ◽  
Po-Wen Hsiao ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Quantum Dots ◽  
Particle Size ◽  
X Ray Diffraction ◽  
One Pot ◽  
X Ray ◽  
Transmission Electron ◽  
Average Size ◽  
Alloy Quantum Dots ◽  
First Time

To the best of our knowledge, this report presents, for the first time, the schematic of the possible chemical reaction for a one-pot synthesis of Zn0.5Cd0.5Se alloy quantum dots (QDs) in the presence of low/high oleylamine (OLA) contents. For high OLA contents, high-resolution transmission electron microscopy (HRTEM) results showed that the average size of Zn0.5Cd0.5Se increases significantly from 4 to 9 nm with an increasing OLA content from 4 to 10 mL. First, [Zn(OAc)2]–OLA complex can be formed by a reaction between Zn(OAc)2 and OLA. Then, Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) data confirmed that ZnO is formed by thermal decomposition of the [Zn(OAc)2]–OLA complex. The results indicated that ZnO grew on the Zn0.5Cd0.5Se surface, thus increasing the particle size. For low OLA contents, HRTEM images were used to estimate the average sizes of the Zn0.5Cd0.5Se alloy QDs, which were approximately 8, 6, and 4 nm with OLA loadings of 0, 2, and 4 mL, respectively. We found that Zn(OAc)2 and OLA could form a [Zn(OAc)2]–OLA complex, which inhibited the growth of the Zn0.5Cd0.5Se alloy QDs, due to the decreasing reaction between Zn(oleic acid)2 and Se2−, which led to a decrease in particle size.

scholarly journals An Alternative Route to Obtain Carbon Quantum Dots from Photoluminescent Materials in Peat

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1492 ◽  
Author(s):  
Rafael Souza da Costa ◽  
Wiliam Ferreira da Cunha ◽  
Nizamara Simenremis Pereira ◽  
Artemis Marti Ceschin
Keyword(s):  
Quantum Dots ◽  
Aromatic Compounds ◽  
Elemental Carbon ◽  
Low Cost ◽  
Carbon Quantum Dots ◽  
Raw Material ◽  
Transmission Electron ◽  
Photoluminescent Materials ◽  
Average Size ◽  
Green Coloration

Peat, an organic compound easily found in the soil (easy to acquire), has more than 50% elemental carbon in its composition and can be used as raw material to produce carbon quantum dots (CQDs, C-dots, Carbon Dots). In this work we describe two simple and low-cost routes for the acquisition of these photoluminescent materials based on peat. The final products were characterized by Fourier transform infrared spectroscopy (FTIR), absorption (UV-Vis) and emission (PL) spectra and high-resolution transmission electron microscopy (HRTEM). The produced CQDs have an average size of 3.5 nm and exhibit coloration between blue and green. In addition, it is possible to produce photoluminescence by means of the aromatic compounds also present in the composition of the peat, in turn exhibiting an intense green coloration. The results indicate great versatility of peat for the production of photoluminescent materials.

scholarly journals Environment-dependent Emission Tuning in the Multicolor Nitrogen-doped Carbon Quantum Dots

2021 ◽  
Author(s):  
Dineshkumar Sengottuvelu ◽  
Abdul Kalam Shaik ◽  
Satish Mishra ◽  
Mahsa Abbaszadeh ◽  
Nathan Hammer ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Solid State ◽  
Large Scale ◽  
Low Cost ◽  
Visible Region ◽  
Carbon Quantum Dots ◽  
One Pot ◽  
Nitrogen Doped ◽  
Emission Changes ◽  
Nitrogen Doped Carbon

Carbon quantum dots (CQDs) are fascinating luminous materials from the carbonaceous family and are increasingly being investigated in many optoelectronic applications due to their unique photoluminescence (PL) characteristics. Herein, we report the synthesis of nitrogen-doped carbon quantum dots (NCQDs) from citric acid and m-phenylenediamine using a one-pot hydrothermal approach. The environment-dependent emission changes of NCQDs were extensively investigated in various solvents, in solid-state, and in physically assembled PMMA-PnBA-PMMA copolymer gels in 2-ethyl hexanol. The NCQDs display bright emission in various solvents as well as in solid-state and a temperature-dependent enhanced emission in gels. In detail, these NCQDs exhibit multicolor PL emission across the visible region and its enhancement upon changing the environment (solutions and polymer matrices). The NCQDs also exhibit excitation-dependent PL and solvatochromism, which are rarely observed in CQDs. Most CQDs are non-emissive in the aggregated or solid-state due to the aggregation-caused quenching (ACQ) effect, limiting their solid-state applications. However, these NCQDs display a strong solid-state emission centered at 568 nm ascribed to the presence of abundant surface functional groups, which helps to prevent the - interaction between the NCQDs and to overcome the ACQ effect in the solid-state. Interestingly, the NCQD containing gels display a significant fluorescence enhancement than the NCQDs in 2-ethyl hexanol solution because of the interaction between the polar PMMA blocks and NCQDs. This research opens up the development of large-scale, low-cost multicolor phosphor for the fabrication of optoelectronic devices, sensing, and bioimaging applications.

scholarly journals The Synthesis of Highly Fluorescent Carbon Quantum Dots from Tartaric Acid

2020 ◽  
Vol 10 (6) ◽  
pp. 7337-7342
Keyword(s):  
Quantum Dots ◽  
Tartaric Acid ◽  
Low Cost ◽  
Photovoltaic Cell ◽  
Carbon Quantum Dots ◽  
Fluorescent Properties ◽  
Tem Analysis ◽  
Transmission Electron ◽  
Bio Compatibility ◽  
Fluorescent Carbon

Carbon quantum dots (C-dots) 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 using low-cost hydrothermal treatment of Tartaric acid as a carbon source. The as-synthesized C-dots were characterized by X-ray diffraction (XRD), Transmission electron microscopy (TEM), UV–Vis absorption spectroscopy, Spectrofluorophotometry, Fourier transform infrared spectroscopy (FT-IR). The synthesized C-dots possess stable fluorescent properties, good, bio-compatibility, and high quantum yield. The C-dots are highly crystalline, with longitudinal dimensions of 3.128 ± 0.17 nm. The XRD and TEM analysis indicates that the synthesized C-dots have a nearly spherical morphology and narrow size distribution. The results suggest that the proposed C-dots could be utilized for photovoltaic cell, bioimaging, drug delivery, and biosensor applications.

LUMINESCENT DETERMINATION OF SUGAR IN NATURAL HONEY

2020 ◽  
Vol 0 (4) ◽  
pp. 29-32
Author(s):  
B.M. GAREEV ◽  
◽  
A.M. ABDRAKHMANOV ◽  
G.L. SHARIPOV ◽  
◽  
...  
Keyword(s):  
Quantum Dots ◽  
Laboratory Test ◽  
Aqueous Solutions ◽  
Analytical Method ◽  
Sugar Content ◽  
Carbon Quantum Dots ◽  
Photoluminescence Intensity ◽  
Sucrose Content ◽  
Natural Honey

The photoluminescence of carbon quantum dots synthesized from natural honey and mixtures of honey and sugar has been studied. An increase in the sugar content leads to a decrease in the photoluminescence intensity without changing the shape of the luminescence spectrum of these quantum dots aqueous solutions, which is associated with a decrease in the yield of their synthesis in the sugar presence. The discovered effect can be used to detect sugar in honey. When examining five different market samples of flower honey using this method, two of them showed a significant decrease in the photoluminescence intensity. A laboratory test for compliance with GOST 19792-2017 Standard requirements established an excess of the sucrose content in these samples. Luminescent determination of sugar in honey does not require complicated equipment and can be used to develop a new analytical method for determining the sugar content in counterfeit natural honey.

A green synthetic route for the surface-passivation of carbon dots as an effective multifunctional fluorescent sensor for the recognition and detection of toxic metal ions from aqueous solution

2019 ◽  
Vol 11 (4) ◽  
pp. 490-506 ◽  
Author(s):  
K. Radhakrishnan ◽  
P. Panneerselvam ◽  
M. Marieeswaran
Keyword(s):  
Aqueous Solution ◽  
Quantum Dots ◽  
Carbon Dots ◽  
Surface Passivation ◽  
Fluorescent Sensor ◽  
Toxic Metal ◽  
Carbon Quantum Dots ◽  
Synthetic Route ◽  
One Pot ◽  
Hydrothermal Methods

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.

scholarly journals ZnSe Quantum Dots through a Facile one Pot Synthesis Process

2015 ◽  
Vol 34 ◽  
pp. 73-78
Author(s):  
Irtiqa Syed ◽  
Santa Chawla
Keyword(s):  
Quantum Dots ◽  
Band Gap ◽  
Quantum Confinement Effect ◽  
Hexagonal Phase ◽  
Fluorescence Decay ◽  
Synthesis Process ◽  
One Pot ◽  
One Pot Synthesis ◽  
Transmission Electron ◽  
Average Size

A novel one pot synthesis approach in oleic acid medium was employed to obtain monophasic ZnSe quantum dots (QD) of average size 3.7nm. The QDs were well crystalline in hexagonal phase as revealed by x-ray diffraction and high resolution transmission electron microscopy (HRTEM) studies. The ZnSe QDs exhibit sharp emission peak in the blue (465nm) with 385picosecond fluorescence decay time. The theoretical band gap corresponding to 3.7nm ZnSe QDs matched well with the measured 3.11eV band gap of synthesized QDs which thus showed quantum confinement effect.

scholarly journals Solvothermal Synthesis of Mn3O4Nanoparticle/Graphene Sheet Composites and Their Supercapacitive Properties

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Y. F. Liu ◽  
G. H. Yuan ◽  
Z. H. Jiang ◽  
Z. P. Yao
Keyword(s):  
Electron Microscopy ◽  
Graphene Sheet ◽  
Low Cost ◽  
High Specific Capacitance ◽  
Ethanol Solution ◽  
Diffraction Field ◽  
Electrochemical Performances ◽  
One Pot ◽  
Long Term Stability ◽  
Transmission Electron

Mn3O4nanoparticle/graphene sheet (GM) composites were synthesized via a one-pot and low-cost solvothermal process in an ethanol solution. The as-prepared materials were characterized by X-ray diffraction, field emission scanning electron microscopy, and transmission electron microscopy. Results showed that the nanosized Mn3O4particles had tetragonal hausmannite structure and were successfully loaded on the graphene sheets. Moreover, the electrochemical performances of GM composites produced by different mass percents of Mn2+/graphite oxide (GO) were evaluated by means of cyclic voltammetry and galvanostatic charge-discharge studies. The composite prepared with Mn2+/GO mass percent of 10 : 90 showed a high specific capacitance of 245 F/g at 5 mV/s in the 6 M KOH solution and better long-term stability along with 81% of its initial capacitance after 1200 cycles at 0.5 A/g.

Highly bright and stable white-light-emitting cadmium-free Ag,Mn co-doped Zn–In–S/ZnS quantum dots and their electroluminescence

2018 ◽  
Vol 6 (38) ◽  
pp. 10233-10240 ◽  
Author(s):  
Wen-Jin Zhang ◽  
Chun-Yang Pan ◽  
Fan Cao ◽  
Haoran Wang ◽  
Xuyong Yang
Keyword(s):  
Quantum Dots ◽  
White Light ◽  
Low Cost ◽  
Synthetic Approach ◽  
One Pot ◽  
Light Emitting ◽  
Co Doped

Optimized white light emitting Ag,Mn:Zn–In–S quantum dots (QDs) were synthesized via a simple, scalable, reproducible, and low-cost one-pot non-injection synthetic approach.

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