Effect of reaction time and different solvents ratios on the formed phases and optical properties of formamidinium lead bromide

ABSTRACTNanomedicine is fostering significant advances in the development of platforms for early detection and treatment of diseases. Nanoparticles (NPs) like quantum dots (QDs) exhibit size-dependent optical properties for light-driven technologies, which might become important in bio-imaging, sensing and photo-dynamic therapy (PDT) applications. The present research addresses the synthesis of water-stable Cd-based QDs via a Microwave-Assisted synthesis approach using cadmium sulfate salt, and thioglycolic acid as Cd- and S-precursors, respectively. Selenide ions were available by reductive leaching of metallic Selenium in Sodium bisulfite solution. The size control and the tunability of the optical properties were achieved by a suitable control of the reaction temperature (in the 140°C- 190°C range) and reaction time (10 minutes-40 minutes). X-ray diffraction analyses suggested the development of a CdSe,S face cubic centered structure; the broadening of the diffraction peaks indicated the presence of very small nanocrystals in the samples. The average crystallite size was estimated at 5.50 nm ± 1.17nm and 3.72 nm ± 0.04 nm, for nanoparticles synthesized at 180°C after 40 minutes or 10 minutes of reaction, respectively. HRTEM images confirmed the crystalline nature and the small size of the synthesized nanocrystals. In turn, the exciton was red-shifted from 461nm to 549 nm when the reaction temperature was prolonged from 140°C to 190 °C, suggesting the crystal growth. The corresponding band gap values were approximately 2.2 eV, confirming the quantum confinement effect (bulk value 1.74eV). This red shift was also evidenced in PL measurements where the main emission peak was shifted from 507 nm to 564 nm when the samples were excited at 420 nm. A narrow size-tunable emission also was supported by the full width at half maximum (∼ 45 nm) for the synthesized nanocrystals. The reactive oxygen species generation capability of as-synthesized QDs was also investigated. The correlation between the particle size and the generation of (ROS) by the degradation of methylene blue was evident with a reduction of MB concentration from 10μM to 7.5μM and 6.7μM after 15 minutes of UV irradiation for reaction time of 10 min. and 40 min. respectively. No additional degradation was noticed after 60 minutes of irradiation.

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Influence of adding 5-ammonium valeric acid bomide on the linear and nonlinear optical properties of formamidinium lead bromide perovskite films

Optical Materials ◽

10.1016/j.optmat.2021.111955 ◽

2022 ◽

Vol 124 ◽

pp. 111955

Author(s):

A.M. El-naggar ◽

Mohamed Bakr Mohamed ◽

Rawabi E. Alatawi ◽

Zein K. Heiba ◽

M.M. Osman ◽

...

Keyword(s):

Optical Properties ◽

Nonlinear Optical ◽

Valeric Acid ◽

Nonlinear Optical Properties ◽

Lead Bromide ◽

Linear And Nonlinear

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CONTROLLED SYNTHESIS OF THE ZnWO4 NANOSTRUCTURE AND STUDY OF THEIR STRUCTURAL AND OPTICAL PROPERTIES

Journal of Nonlinear Optical Physics & Materials ◽

10.1142/s0218863512500026 ◽

2012 ◽

Vol 21 (01) ◽

pp. 1250002 ◽

Cited By ~ 2

Author(s):

NGUYEN MANH HUNG ◽

LAM THI HANG ◽

NGUYEN VAN KHANH ◽

DU THI XUAN THAO ◽

NGUYEN VAN MINH

Keyword(s):

Electron Microscopy ◽

Grain Size ◽

Optical Properties ◽

Reaction Time ◽

X Ray Diffraction ◽

Structural And Optical Properties ◽

Calcination Time ◽

Transmission Electron ◽

Pure Phase ◽

Size And Morphology

We investigate the effects of calcination time and concentration of solution on the structure, as well as optical properties in ZnWO4 nanopowder prepared by hydrothermal method. The prepared powder were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman scattering, optical absorption and photoluminescent spectroscopy (PL). It is shown that the grain size and morphology of ZnWO4 nanopowder can be controlled by adjusting the reaction time as well as the concentration of the solution. The resultant sample is a pure phase of ZnWO4 without any impurities. The result showed that the optical property of ZnWO4 nanopowders depend on their grain size. The optical band gap becomes narrower as the reaction time or concentration of solution is increased. The improved PL properties of the ZnWO4 crystallites can be obtained with the optimal concentration of the solution.

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Tailoring Blue-Green Double Emissions in Carbon Quantum Dots via Co-Doping Engineering by Competition Mechanism between Chlorine-Related States and Conjugated π-Domains

Nanomaterials ◽

10.3390/nano8090635 ◽

2018 ◽

Vol 8 (9) ◽

pp. 635 ◽

Cited By ~ 10

Author(s):

Xue Sun ◽

Huilian Liu ◽

Lili Yang ◽

Xinying Wang ◽

Weiqiang Yang ◽

...

Keyword(s):

Quantum Dots ◽

Optical Properties ◽

Reaction Time ◽

Quantum Confinement ◽

Quantum Confinement Effect ◽

Carbon Quantum Dots ◽

Confinement Effect ◽

Co Doping ◽

Photoelectric Properties ◽

Co Doped

Representing single-layer to tens of layers of graphene in a size less than 30 nm, carbon quantum dots (CQDs) is becoming an advanced multifunctional material for its unique optical, electronic, spin and photoelectric properties induced by the quantum confinement effect and edge effect. In present work, upon co-doping engineering, nitrogen and chlorine co-doped CQDs with uniquely strong blue-green double emissions are developed via a facile and one-pot hydrothermal method. The crystalline and optical properties of CQDs have been well manipulated by tuning the mole ratio of nitrogen/chlorine and the reaction time. The characteristic green emission centered at 512 nm has been verified, originating from the chlorine-related states, the other blue emissions centered at 460 nm are attributed to the conjugated π-domain. Increasing the proportion of 1,2,4-benzentriamine dihydrochloride can effectively adjust the bandgap of CQDs, mainly caused by the synergy and competition of chlorine-related states and the conjugated π-domain. Prolonging the reaction time promotes more nitrogen and chlorine dopants incorporate into CQDs, which inhibits the growth of CQDs to reduce the average size of CQDs down to 1.5 nm, so that the quantum confinement effect dominates into play. This work not only provides a candidate with excellent optical properties for heteroatoms-doped carbon materials but also benefits to stimulate the intensive studies for co-doped carbon with chlorine as one of new dopants paradigm.

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Solvothermal Growth of Flower-Like Morphology from Nanorods of Copper Sulfides

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2008.18221 ◽

2008 ◽

Vol 8 (3) ◽

pp. 1523-1527 ◽

Cited By ~ 4

Author(s):

Poulomi Roy ◽

Suneel Kumar Srivastava

Keyword(s):

Optical Properties ◽

Reaction Time ◽

Copper Sulfide ◽

Solvothermal Synthesis ◽

Stoichiometric Composition ◽

X Ray Diffraction ◽

Reaction Duration ◽

X Ray ◽

Copper Sulfides ◽

Diffraction Patterns

The present work reports the effect of reaction time on solvothermal synthesis of copper sulfides from CuCl2·2H2O and thiourea with various compositions and morphologies using ethylenediamine as solvent at 120 °C. X-ray diffraction patterns of the products at different durations shows the development of different stoichiometric composition of copper sulfides in where Cu:S ratio increases from 1.39 to 1.79 indicating transformation of Cu39S28 to Cu7S4. As inferred by EDX and XPS studies of the final products. SEM shows the growth of bundles of nanorods of length ≈1 μm and diameter in nanometer range are observed after 6 h. On increasing the reaction duration to 9 h, nanorods tends to combines with each other and growth occurs in six directions and after 12 h leads to the formation of flower-like morphology of copper sulfide. The optical properties of these products also have been studied.

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Blue-luminescent organic lead bromide perovskites: highly dispersible and photostable materials

Journal of Materials Chemistry A ◽

10.1039/c5ta01765c ◽

2015 ◽

Vol 3 (26) ◽

pp. 14039-14045 ◽

Cited By ~ 64

Author(s):

Soranyel Gonzalez-Carrero ◽

Guillermo Mínguez Espallargas ◽

Raquel E. Galian ◽

Julia Pérez-Prieto

Keyword(s):

Optical Properties ◽

Quantum Yield ◽

Uv Light ◽

Luminescence Quantum Yield ◽

Reaction Yield ◽

Inorganic Hybrid ◽

High Reaction ◽

Lead Bromide ◽

Organic Lead

Blue-luminescent and dispersible organic–inorganic hybrid perovskites can be produced with a high reaction yield and valuable optical properties, such as luminescence quantum yield over 20% and high photostability under UV light. This material can be assembled–disassembled reversibly.

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Composition-, Size-, and Surface Functionalization-Dependent Optical Properties of Lead Bromide Perovskite Nanocrystals

The Journal of Physical Chemistry Letters ◽

10.1021/acs.jpclett.0c00266 ◽

2020 ◽

Vol 11 (6) ◽

pp. 2079-2085 ◽

Cited By ~ 4

Author(s):

Palvasha Ijaz ◽

Muhammad Imran ◽

Márcio M. Soares ◽

Hélio C. N. Tolentino ◽

Beatriz Martín-García ◽

...

Keyword(s):

Optical Properties ◽

Surface Functionalization ◽

Perovskite Nanocrystals ◽

Lead Bromide

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Coating Time Effect on Surface Structures of Silica-Encapsulated Gold Nanoparticles

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.79-82.935 ◽

2009 ◽

Vol 79-82 ◽

pp. 935-938

Author(s):

Qin Qu ◽

Shan Tang Liu

Keyword(s):

Gold Nanoparticles ◽

Optical Properties ◽

Reaction Time ◽

Slight Modification ◽

Silica Shell ◽

Surface Structures ◽

Absorption Peak ◽

Experimental Conditions ◽

Visible Absorption ◽

Density Surface

This paper reports the silica density, surface structures and optical properties of gold nanoparticles coated with different thickness of silica shells. The gold nanoparticles encapsulated with amorphous silica shells were prepared in a slight modification of Stǒber method. The silica-shell thickness could be varied from 20 to 50 nm by controlling the experimental conditions, such as reaction time. Transmission Electron Microscopy (TEM) and UV-Visible absorption spectroscopy were employed to characterize the size, shell density, surface structures and the optical properties of these silica-coated gold nanoparticles. The TEM images demonstrated that the density of the silica shell were depended on the reaction time, and the surface morphology was changed from porous structures in the initial coating to the final continuous and smooth silica surface. With the increasing of the reaction time, the silica-coated gold nanoparticles became more and more round and monodispersed. UV-Vis spectra showed that surface plasmon absorption peak had a red-shifted of 3~12 nm on increasing the thickness of silica shell from 20 to 50 nm. A possible mechanism of silica formation on gold nanoparticles was proposed on the basis of silica shell density and the shift of absorption peak of coated gold nanoparticles.

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Zinc blende versus wurtzite ZnS nanoparticles: control of the phase and optical properties by tetrabutylammonium hydroxide

Physical Chemistry Chemical Physics ◽

10.1039/c4cp02611j ◽

2014 ◽

Vol 16 (37) ◽

pp. 20127-20137 ◽

Cited By ~ 64

Author(s):

F. A. La Porta ◽

J. Andrés ◽

M. S. Li ◽

J. R. Sambrano ◽

J. A. Varela ◽

...

Keyword(s):

Optical Properties ◽

Reaction Time ◽

Cost Effective ◽

Phase Control ◽

Degree Of Crystallinity ◽

Zns Nanoparticles ◽

Fast Reaction ◽

Tetrabutylammonium Hydroxide ◽

Fast Reaction Time ◽

Zinc Blende

We demonstrated phase control, mediated by the presence of tetrabutylammonium hydroxide, in the growth of ZnS crystals by using a cost effective MAS method; a very moderate temperature (140 °C) and a very fast reaction time are sufficient to produce nanostructures with a good degree of crystallinity.

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