scholarly journals Eco Friendly Synthesis of Carbon Dot by Hydrothermal Method for Metal Ions Salt Identification

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7604
Author(s):  
Hasan Shabbir ◽  
Tomasz Tokarski ◽  
Ditta Ungor ◽  
Marek Wojnicki
Keyword(s):  
Metal Ion ◽  
Hydrothermal Reaction ◽  
Synthesis Method ◽  
Emission Spectra ◽  
Carbon Quantum Dots ◽  
Photoluminescence Properties ◽  
Step Method ◽  
Synthesis Time ◽  
One Step ◽  
The One

In this work, we report the synthesis method of carbon quantum dots (CDs) using the one-step method for fast and effective metal ion determination. Ascorbic acid was used as an inexpensive and environmentally friendly precursor. High-pressure and high-temperature reactors were used for this purpose. Microscopic characterization revealed the size of CDs was in the range of 2–6 nm and they had an ordered structure. The photoluminescence properties of the CDs depend on the process temperature, and we obtained the highest PL spectra for 6 h of hydrothermal reaction. The maximum emission spectra depend poorly on synthesis time. Further characterization shows that CDs are a good contender for sensing Fe3+ in aqueous systems and can detect concentrations up to 0.49 ppm. The emission spectra efficiency was enhanced by up to 200% with synthesis time.

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 Facile one-step synthesis of quaternary AgInZnS quantum dots and their applications for causing bioeffects and detecting Cu2+

RSC Advances ◽  
2020 ◽  
Vol 10 (16) ◽  
pp. 9172-9181 ◽  
Author(s):  
Xiao-Le Han ◽  
Qingyu Li ◽  
Hao Hao ◽  
Chenyin Liu ◽  
Run Li ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Hydrothermal Reaction ◽  
Water Soluble ◽  
Step Method ◽  
One Step

Water-soluble AgInZnS quantum dots were synthesized with glutathione as a stabilizer by a facile one-step method based on a hydrothermal reaction at 110 °C. It exhibited excellent optical properties, which can be used as sensor to detect Cu2+.

Bias in the one-step method for pooling study results

1990 ◽  
Vol 9 (3) ◽  
pp. 247-252 ◽  
Author(s):  
Sander Greenland ◽  
Alberto Salvan
Keyword(s):  
Step Method ◽  
Study Results ◽  
One Step ◽  
The One

ChemInform Abstract: Cycling Properties of Sc- and Ce-Doped NaAlH4Hydrogen Storage Materials Prepared by the One-Step Direct Synthesis Method.

ChemInform ◽  
2009 ◽  
Vol 40 (22) ◽  
Author(s):  
Borislav Bogdanovic ◽  
Michael Felderhoff ◽  
Andre Pommerin ◽  
Ferdi Schueth ◽  
Nick Spielkamp ◽  
...  
Keyword(s):  
Direct Synthesis ◽  
Synthesis Method ◽  
Storage Materials ◽  
One Step ◽  
The One

Quench ionic flash nano precipitation as a simple and tunable approach to decouple growth and functionalization for the one-step synthesis of functional LnPO4-based nanoparticles in water

2018 ◽  
Vol 54 (68) ◽  
pp. 9438-9441 ◽  
Author(s):  
Nathalie M. Pinkerton ◽  
Khadidja Hadri ◽  
Baptiste Amouroux ◽  
Leah Behar ◽  
Christophe Mingotaud ◽  
...  
Keyword(s):  
Hybrid Nanoparticles ◽  
Step Method ◽  
Inorganic Hybrid ◽  
One Step ◽  
The One

A novel, one-step method for the synthesis of functional, organic–inorganic hybrid nanoparticles is reported.

scholarly journals Geopolymer-TiO2 Nanocomposites for Photocsatalysis: Synthesis by One-Step Adding Treatment Versus Two-Step Acidification Calcination

Minerals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 658 ◽  
Author(s):  
Xiaohui Yang ◽  
Yi Liu ◽  
Chunjie Yan ◽  
Ronghua Peng ◽  
Hongquan Wang
Keyword(s):  
Photocatalytic Activity ◽  
Treatment Process ◽  
Photocatalytic Efficiency ◽  
Step Method ◽  
Calcination Process ◽  
Tio2 Particles ◽  
Study Results ◽  
Photocatalytic Activities ◽  
One Step ◽  
The One

Geopolymer-TiO2 nanocomposites were prepared by two different techniques, namely the two-step acidification calcination treatment and one-step adding method. The potential photocatalytic activities of geopolymer-TiO2 nanocomposites prepared by the two different methods were tested and compared. Nanocomposites prepared via the one-step process showed better photocatalytic activity. The amount of TiO2 particles loaded on the surface of the foaming materials was investigated by XRD and SEM-Mapping. By comparing with the sample obtained from two-step treatment, the TiO2 particles were distributed uniformly on the surface of the foaming materials for the sample obtained from the one-step method in this study. Results showed that the specific surface area of the geopolymer-TiO2 prepared by the one-step treatment process (28.67 m2/g) was significantly lower than the two-step acidification calcination process (215.04 m2/g), while the photocatalytic efficiency with methylene blue trihydrate (MB) was better. This is due to the more stable structure of geopolymer-TiO2 nanocomposites, the better dispersion and more loading of TiO2 particles on the foaming materials surfaces, leading to the enhanced photocatalytic activity.

scholarly journals Microwave-assisted synthesis of high thermal stability and colourless polyimides containing pyridine

2019 ◽  
Vol 6 (6) ◽  
pp. 190196 ◽  
Author(s):  
Kai Cheng ◽  
Jie-pin Hu ◽  
Yan-cheng Wu ◽  
Chu-qi Shi ◽  
Zhi-geng Chen ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Synthesis Method ◽  
Optical Transmittance ◽  
Aromatic Diamine ◽  
Microwave Assisted Synthesis ◽  
Step Method ◽  
Light Emitting ◽  
Microwave Assisted ◽  
One Step ◽  
Biphenyltetracarboxylic Dianhydride

A novel aromatic diamine containing pyridyl side group, 4-pyridine-4,4-bis(3,5-dimethyl-5-aminophenyl)methane (PyDPM), was successfully synthesized via electrophilic substitution reaction. The polyimides (PIs) containing pyridine were obtained via the microwave-assisted one-step polycondensation of the PyDPM with pyromellitic dianhydride (PMDA), 3,3′,4,4′-biphenyltetracarboxylic dianhydride (BPDA), 3,3′,4,4′-diphenylether tetracarboxylic dianhydride (ODPA) and 4,4′-(hexafluoroisopropylidene)diphthalic anhydride (6FDA). Contrarily to the reported similar PIs, these PIs exhibit much higher thermal stability or heat resistance, i.e. high glass transition temperatures ( T g s) in the range of 358–473°C, and the decomposition temperatures at 5% weight loss over 476°C under nitrogen. They can afford flexible and strong films with tensile strength of 82.1–93.3 MPa, elongation at break of 3.7%–15.2%, and Young's modulus of 3.3–3.8 GPa. Furthermore, The PI films exhibit good optical transparency with the cut-off wavelength at 313–366 nm and transmittance higher than 73% at 450 nm. The excellent thermal and optical transmittance can be attributed to synthesis method and the introduction of pyridine rings and ortho-methyl groups. The inherent viscosities of PIs via one-step method were found to be 0.58–1.12 dl g −1 in DMAc, much higher than those via two-step method. These results indicate these PIs could be potential candidates for optical substrates of organic light emitting diodes (OLEDs).

scholarly journals One-Step Synthesis of Spherical γ-Fe2O3 Nanopowders and the Evaluation of Their Photocatalytic Activity for Orange I Degradation

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Chunhua Liang ◽  
Hui Liu ◽  
Jianmin Zhou ◽  
Xiaochun Peng ◽  
Haizhou Zhang
Keyword(s):  
Particle Size ◽  
Reaction Time ◽  
Synthesis Method ◽  
Total Pore Volume ◽  
Xrd Analysis ◽  
Bet Surface Area ◽  
Particle Sizes ◽  
Aqueous Synthesis ◽  
One Step ◽  
The One

Maghemite (γ-Fe2O3) nanopowders were synthesized under aeration (oxidizing) conditions by aqueous synthesis in this study. The microstructures of the prepared powders were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and BET-BJH. The XRD analysis and the chemical experiments showed that well-crystallized γ-Fe2O3 nanoparticles were successfully obtained with a mean particle size of approximately 17 nm. The prepared γ-Fe2O3 was spherical with a BET surface area of 14.357 m2/g and a total pore volume of 0.050 cm3/g. Varying the reaction conditions, such as pH, temperature, and reaction time, we obtained crystallized γ-Fe2O3 powders with different crystallization extent and different particle sizes. When the pH of the reaction suspension was increased, the reaction time was prolonged, and the reaction temperature was increased, the γ-Fe2O3 powders underwent superior crystallization and had larger particle sizes. All the obtained γ-Fe2O3 powders had significant photocatalytic activities under both UV and visible light irradiation for Orange I degradation, and the powders with better crystallization and larger particle size had relatively lower activities for Orange I photocatalytic degradation. The one-step aqueous synthesis method presented in this paper may provide an advantageous pathway to synthesize large quantities of this important iron oxide.

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