scholarly journals Sugar-Mediated Green Synthesis of Silver Selenide Semiconductor Nanocrystals under Ultrasound Irradiation

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 5193
Author(s):  
Daniela Armijo García ◽  
Lupe Mendoza ◽  
Karla Vizuete ◽  
Alexis Debut ◽  
Marbel Torres Arias ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Optical Properties ◽  
Colloidal Stability ◽  
Semiconductor Nanocrystals ◽  
Cost Effective ◽  
Ultrasound Irradiation ◽  
Silver Selenide ◽  
Easy Method ◽  
Stabilizing Agents ◽  
Vis Spectroscopy

Silver selenide (Ag2Se) is a promising nanomaterial due to its outstanding optoelectronic properties and countless bio-applications. To the best of our knowledge, we report, for the first time, a simple and easy method for the ultrasound-assisted synthesis of Ag2Se nanoparticles (NPs) by mixing aqueous solutions of silver nitrate (AgNO3) and selenous acid (H2SeO3) that act as Ag and Se sources, respectively, in the presence of dissolved fructose and starch that act as reducing and stabilizing agents, respectively. The concentrations of mono- and polysaccharides were screened to determine their effect on the size, shape and colloidal stability of the as-synthesized Ag2Se NPs which, in turn, impact the optical properties of these NPs. The morphology of the as-synthesized Ag2Se NPs was characterized by transmission electron microscopy (TEM) and both α- and β-phases of Ag2Se were determined by X-ray diffraction (XRD). The optical properties of Ag2Se were studied using UV–Vis spectroscopy and its elemental composition was determined non-destructively using scanning electron microscopy–energy-dispersive spectroscopy (SEM–EDS). The biological activity of the Ag2Se NPs was assessed using cytotoxic and bactericidal approaches. Our findings pave the way to the cost-effective, fast and scalable production of valuable Ag2Se NPs that may be utilized in numerous fields.

Study on Dispersion and Characterization of Functionalized MWCNTs Prepared by Wet Oxidation

2014 ◽  
Vol 661 ◽  
pp. 8-13 ◽  
Author(s):  
Intan Syaffinazzilla Zaine ◽  
N.A.M. Napiah ◽  
Azmi Mohamad Yusof ◽  
A.N. Alias ◽  
A.M.M. Ali ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Relative Intensity ◽  
Colloidal Stability ◽  
Structural Defects ◽  
Wet Oxidation ◽  
Defect Level ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Functionalized Mwcnts

The MWCNTs was functionalized by refluxing commercial MWCNTs (a-MWCNTs) in concentrated HNO3/H2SO4 (3:1 v/v) at 100°C for 6 hours. The dispersion of a-MWCNTs and functionalized MWCNTs (f-MWCNTs) were observed after 1 hour sonication in ethanol. Both samples were characterized by UV-vis spectroscopy for dispersion behavior. The dried f-MWCNTs and a-MWCNTs were characterized by Raman spectroscopy to estimate the defect level. The morphology of the samples were analyzed by Transmission Electron Microscopy (TEM). The f-MWCNTs was well dispersed in ethanol within 2 weeks of observations period. The colloidal stability of a-MWCNTs was low as it was easily sediment after 24 hours. The UV-vis spectra of f-MWCNTs show maximum absorbance at 250 nm meanwhile no absorbance was observed for a-MWCNTs. Analysis from Raman spectrum shows that the f-MWCNTs have relative intensity of 1.101 which is higher than a-MWCNTs that have relative intensity of 0.935. The image from TEM revealed that the f-MWCNTs have structural defects and the absence of amorphous carbon on sidewall meanwhile the a-MWCNTs indicate otherwise.

NOVEL AND COST-EFFECTIVE SYNTHESIS OF SILVER NANOCRYSTALS: A GREEN SYNTHESIS

NANO ◽  
2011 ◽  
Vol 06 (04) ◽  
pp. 295-300 ◽  
Author(s):  
NISHAT ARSHI ◽  
FAHEEM AHMED ◽  
M. S. ANWAR ◽  
SHALENDRA KUMAR ◽  
BON HEUN KOO ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Secondary Phase ◽  
Cost Effective ◽  
Silver Foil ◽  
Face Centered Cubic ◽  
X Rays ◽  
Xrd Pattern ◽  
Average Grain Size ◽  
Vis Spectroscopy ◽  
Face Centered

This paper reports the study on the synthesis and characterization of silver nanocrystals by a two-step synthesis procedure. The first step is the solution-free hand grinding of silver foil and sugar at room temperature for few minutes. The second step is the thermal decomposition of silver/sugar composite to form silver nanocrystals. The as-synthesized silver nanocrystals were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), ultraviolet visible (UV/Vis) spectroscopy, atomic force microscopy (AFM) and transmission electron microscopy (TEM) studies. The XRD pattern showed a face-centered cubic structure (single phase) with high crystallinity. The lattice parameters calculated from XRD pattern were found to be a = 4.12 Å for silver nanocrystals with average grain size of ~ 19 nm. The energy dispersive analysis of X-rays (EDAX) of silver nanocrystals confirmed the presence of silver and no peak of any secondary phase was detected. FESEM and AFM studies showed that the crystals have cube-like morphology. TEM results showed that the size of silver nanocrystals was found to be ~ 22 nm. This novel synthesis route, not reported earlier, would be a promising candidate for a variety of future applications of silver nanocrystals.

A Facile and TGA Free Hydrothermal Synthesis of SnS Nanoparticles

NANO ◽  
2017 ◽  
Vol 12 (10) ◽  
pp. 1750120 ◽  
Author(s):  
M. Gurubhaskar ◽  
Narayana Thota ◽  
M. Raghavender ◽  
Y. P. Venkata Subbaiah ◽  
G. Hema Chandra ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Reaction Temperature ◽  
Life Time ◽  
Cost Effective ◽  
Dual Band ◽  
X Ray Diffraction ◽  
Chloride Dihydrate ◽  
Transmission Electron ◽  
Absorber Material ◽  
Vis Spectroscopy

In this paper, we employed a simple and cost-effective thioglycolic acid (TGA) free hydrothermal method, based on thiourea hydrolysis of stannous chloride dihydrate [SnCl2.2H2O] at 160[Formula: see text]C–190[Formula: see text]C for 6[Formula: see text]h, for the synthesis of SnS nanoparticles. The effect of hydrothermal autoclave reaction temperature on various properties of SnS nanoparticles have been examined at length using X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), field-emission scanning electron microscopy attached with EDAX (FE-SEM), transmission electron microscopy (TEM) and ultraviolet-visible (UV-Vis) spectroscopy. The results suggest that the crystallization of orthorhombic SnS nanoparticles, with size varying from 3[Formula: see text]nm to 5[Formula: see text]nm, formed at R[Formula: see text]C. Further, the formation of SnS phase was confirmed by an IR Sn-S characteristic bands around 2350[Formula: see text]cm[Formula: see text], 1041[Formula: see text]cm[Formula: see text] and 570[Formula: see text]cm[Formula: see text], and four distinguished Raman peaks at 95[Formula: see text]cm[Formula: see text], 160[Formula: see text]cm[Formula: see text], 189[Formula: see text]cm[Formula: see text] and 220[Formula: see text]cm[Formula: see text]. The mechanism for the formation of SnS nanoparticles have been proposed and discussed. The SnS nanoparticles have exhibited reaction temperature dependent morphological features like nanoflowers, nanoflakes, spherical nanoparticles and nanogranules. The absorbance studies indicated both strong direct and weak indirect allowed transitions for SnS nanoparticles and the associated band gaps were found to be 1.5[Formula: see text]eV and 1.19[Formula: see text]eV, respectively. The dual band gap combination of SnS would favor strong direct absorption of carriers and improved minority carrier life time due to indirect nature, which means the grown particles are suitable for ideal absorber material for solar cell applications.

scholarly journals Photoremediation of methylene blue by biosynthesized ZnO/Fe3O4 nanocomposites using Callistemon viminalis leaves aqueous extract: A comparative study

2021 ◽  
Vol 10 (1) ◽  
pp. 1912-1925
Author(s):  
Poonam Dwivedi ◽  
Indu Jatrana ◽  
Azhar U. Khan ◽  
Azmat Ali Khan ◽  
Honey Satiya ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Methylene Blue ◽  
Photoelectron Spectroscopy ◽  
Water Extract ◽  
Cost Effective ◽  
Nitrogen Atmosphere ◽  
Stabilizing Agents ◽  
Photodegradation Efficiency ◽  
Crystallite Sizes ◽  
Callistemon Viminalis

Abstract This article reports a simple, cost-effective, and eco-friendly biosynthesis of ZnO/Fe3O4 nanocomposites using Callistemon viminalis leaves’ water extract. For the first time, we used a green synthetic route via C. viminalis leaves’ extract to prepare ZnO/Fe3O4 nanocomposites (NCs) using zinc acetate and ferric chloride as precursor materials. Fourier transform infrared (FTIR) spectroscopic results revealed polyphenolic compounds mainly phenolic acids present in the plant extract acted as both reducing and stabilizing agents to synthesize ZnO/Fe3O4 NCs. Outcomes of XRD and X-ray photoelectron spectroscopy confirmed the formation of ZnO–Fe3O4 heterojunction in ZnO/Fe3O4 NCs, with crystallite sizes of 45, 35, and 60 nm, respectively, according to Debye–Scherrer’s formula. EDX confirmed Zn, Fe, and O in the ZnO/Fe3O4 nanocomposite. Scanning electron microscopy and transmission electron microscopy (TEM) analyses revealed the existence of both ZnO and Fe3O4 in the NCs with some agglomeration. The thermal stability of NCs was evaluated using thermogravimetric analysis (TGA) and differential thermal analysis (DTA) in a nitrogen atmosphere. In addition, as-prepared ZnO/Fe3O4 NCs along with biosynthesized ZnO and Fe3O4 (prepared by C. viminalis extract) nanoparticles were examined for photodegradation of methylene blue under visible light irradiation for 150 min. The result reveals that the photodegradation efficiency of ZnO/Fe3O4 NCs (99.09%) was higher compared to that of monometallic ZnO (84.7%) and Fe3O4 (37.1%) nanoparticles.

scholarly journals One pot synthesis of silver nanoparticles using a cyclodextrin containing polymer as reductant and stabilizer

2014 ◽  
Vol 5 ◽  
pp. 380-385 ◽  
Author(s):  
Arkadius Maciollek ◽  
Helmut Ritter
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Silver Nanoparticles ◽  
Optical Properties ◽  
Silver Nitrate ◽  
Room Temperature ◽  
One Pot ◽  
One Pot Synthesis ◽  
Transmission Electron ◽  
Vis Spectroscopy

A facile and one pot synthesis of silver nanoparticles with narrow size distributions using silver nitrate and a copolymer 1 from N-isopropylacrylamide (NIPAM) and mono-(1H-triazolylmethyl)-2-methylacryl-β-cyclodextrin acting as reductant and stabilizer without using any additional reducing agent is reported. The reduction was carried out in aqueous solution under pH neutral conditions at room temperature. The results of dynamic light scattering analysis and transmission electron microscopy show adjustable particle sizes from 30–100 nm, due to variation of silver nitrate concentration, the polymeric reducing and stabilisation agent concentration or reaction time. The spherical structure of the silver nanoparticles has been confirmed by UV–vis spectroscopy and transmission electron microscopy. The optical properties of the nanoparticles have also been characterized by fluorescence spectroscopy. The formed spherical particles are stable in aqueous medium at room temperature over a period of several weeks. Furthermore the changes in the optical properties of the nanoparticles due to thermo induced volume phase transition behavior of the thermoresponsive cyclodextrin containing polymer 1 have been characterized by UV–vis spectroscopy.

Synthesis of Fe2+ Ion Doped ZnS Nanoparticles

2014 ◽  
Vol 879 ◽  
pp. 155-163 ◽  
Author(s):  
Rahizana Mohd Ibrahim ◽  
Markom Masturah ◽  
Huda Abdullah
Keyword(s):  
Electron Microscopy ◽  
Optical Properties ◽  
Quantum Confinement Effect ◽  
Band Gap Energy ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Co Precipitation

Nanoparticles of Zn1-xFexS ( x=0.0,0.1,0.2 and 0.3) were prepared by chemical co-precipitation method from homogenous solution of zinc and ferum salt at room temperature with controlled parameter. These nanoparticles were sterically stabilized using Sodium Hexamethaphospate (SHMP). Here, a study of the effect of Fe doping on structure, morphological and optical properties of nanoparticles was undertaken. Elemental analysis, morphological and optical properties have been investigated by Fourier-Transform-Infrared spectroscopy (FT-IR), X-Ray Fluorescence (XRF), Field Emmision Scanning Electron Microscopy (FESEM), X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and UV-Visible Spectroscopy. FTIR measurement confirmed the presence of SHMP in the nanoparticles structure with the FESEM images depicting considerable less agglomeration of particles with the presence of SHMP. While XRF results confirm the presence of Fe2+ ion as prepared in the experiment. The particles sizes of the nanoparticles lay in the range of 2-10 nm obtained from the TEM image were in agreement with the XRD results. The absorption edge shifted to lower wavelengths with an increase in Fe concentration shown in the UV-Vis spectroscopy. The band gap energy value was in the range of 4.95 5.15 eV. The blueshift is attributed to the quantum confinement effect.

scholarly journals Facile Biogenic Synthesis and Characterization of Seven Metal-Based Nanoparticles Conjugated with Phytochemical Bioactives Using Fragaria ananassa Leaf Extract

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 3025
Author(s):  
Maryam Bayat ◽  
Meisam Zargar ◽  
Tamara Astarkhanova ◽  
Elena Pakina ◽  
Sergey Ladan ◽  
...  
Keyword(s):  
Leaf Extract ◽  
Metal Oxide Nanoparticles ◽  
Cost Effective ◽  
Correlation Spectroscopy ◽  
Oxide Nanoparticles ◽  
Fragaria Ananassa ◽  
X Ray ◽  
Stabilizing Agents ◽  
Characterization Techniques ◽  
Vis Spectroscopy

In this investigation, for the first time, we used Fragaria ananassa (strawberry) leaf extract as a source of natural reducing, capping or stabilizing agents to develop an eco-friendly, cost-effective and safe process for the biosynthesis of metal-based nanoparticles including silver, copper, iron, zinc and magnesium oxide. Calcinated and non-calcinated zinc oxide nanoparticles also synthesized during a method different from our previous study. To confirm the successful formation of nanoparticles, different characterization techniques applied. UV-Vis spectroscopy, X-ray Diffraction (XRD) spectroscopy, Field Emission Scanning Electron Microscopy (FESEM) coupled with Energy Dispersive X-ray Spectroscopy (EDS), Photon Cross-Correlation Spectroscopy (PCCS) and Fourier Transformed Infrared Spectroscopy (FT-IR) were used to study the unique structure and properties of biosynthesized nanoparticles. The results show the successful formation of metal-based particles in the range of nanometer, confirmed by different characterization techniques. Finally, the presented approach has been demonstrated to be effective in the biosynthesis of metal and metal oxide nanoparticles.

scholarly journals Biosynthesis, characterisation and therapeutic applications of plant-mediated silver nanoparticles

2018 ◽  
Vol 83 (5) ◽  
pp. 515-538 ◽  
Author(s):  
Andreia Corciova ◽  
Bianca Ivanescu
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Nanoparticle Synthesis ◽  
Special Importance ◽  
X Ray Diffraction ◽  
X Ray ◽  
Stabilizing Agents ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Nanoparticles Synthesis

Nanotechnology is one of the most studied domains, and nanoparticle synthesis, especially of silver nanoparticles, has gained special importance due to their properties, biocompatibility and applications. Today, the processes of nanoparticles synthesis tend toward the development of inexpensive, simple, non-toxic and environmentally friendly methods. Thus, the use of plants in the synthesis of silver nanoparticles has attracted considerable interest because biomolecules can act as both reducing and stabilizing agents. This survey aims at discussing the conditions for obtaining silver nanoparticles using plants and their characterization by several methods, such as FTIR and UV?Vis spectroscopy, X-ray diffraction, and scanning and transmission electron microscopy. In addition, it examines some of the most common biological uses of silver nanoparticles: antibacterial, antioxidant and cytotoxic.

scholarly journals A comparative study on the electronic and optical properties of Sb-=SUB=-2-=/SUB=-Se-=SUB=-3-=/SUB=- thin film

2017 ◽  
Vol 51 (12) ◽  
pp. 1673
Author(s):  
M. Kamruzzaman ◽  
Chaoping Liu ◽  
A.K.M. Farid Ul Islam ◽  
J.A. Zapien
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Optical Properties ◽  
Band Gap ◽  
Annealed Film ◽  
Dielectric Constants ◽  
Thermal Evaporation Method ◽  
X Ray ◽  
Electronic And Optical Properties ◽  
Vis Spectroscopy

The thin film of Sb2Se3 was deposited by thermal evaporation method and the film was annealed in N2 flow in a three zone furnace at a temperature of 290oC for 30 min. The structural properties were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and Raman spectroscopy, respectively. It is seen that the as-deposited film is amorphous and the annealed film is polycrystalline in nature. The surface of Sb2Se3 film is oxidized with a thickness of 1.15 nm investigated by X-ray photolecetron spectroscopy (XPS) measurement. Spectroscopic ellipsometry (SE) and UV-vis spectroscopy measurements were carried out to study the optical properties of Sb2Se3 film. In addition, the first principles calculations were applied to study the electronic and optical properties of Sb2Se3. From the theoretical calculation it is seen that Sb2Se3 is intrinsically an indirect band gap semiconductor. Importantly, the experimental band gap is in good agreement with the theoretical band gap. Furthermore, the experimental values of n,k,varepsilon1, and varepsilon2 are much closer to the theoretical results. However, the obtained large dielectric constants and refractive index values suggest that exciton binding energy in Sb2Se3 should be relatively small and an antireflective coating is recommended to enhance the light absorption of Sb2Se3 for thin film solar cells application. DOI: 10.21883/FTP.2017.12.45184.8396

scholarly journals Hydrogenated Nanocrystalline Silicon Thin Films Prepared by Hot-Wire Method with Varied Process Pressure

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
V. S. Waman ◽  
A. M. Funde ◽  
M. M. Kamble ◽  
M. R. Pramod ◽  
R. R. Hawaldar ◽  
...  
Keyword(s):  
Optical Properties ◽  
Cost Effective ◽  
Nanocrystalline Silicon ◽  
Hot Wire ◽  
Structural And Optical Properties ◽  
Silicon Thin Films ◽  
Hydrogen Dilution ◽  
Process Pressure ◽  
Vis Spectroscopy ◽  
Wire Method

Hydrogenated nanocrystalline silicon films were prepared by hot-wire method at low substrate temperature (200∘C) without hydrogen dilution of silane (SiH4). A variety of techniques, including Raman spectroscopy, low angle X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, atomic force microscopy (AFM), and UV-visible (UV-Vis) spectroscopy, were used to characterize these films for structural and optical properties. Films are grown at reasonably high deposition rates (>15 Å/s), which are very much appreciated for the fabrication of cost effective devices. Different crystalline fractions (from 2.5% to 63%) and crystallite size (3.6–6.0 nm) can be achieved by controlling the process pressure. It is observed that with increase in process pressure, the hydrogen bonding in the films shifts from Si–H to Si–H2and(Si–H2)ncomplexes. The band gaps of the films are found in the range 1.83–2.11 eV, whereas the hydrogen content remains <9 at.% over the entire range of process pressure studied. The ease of depositing films with tunable band gap is useful for fabrication of tandem solar cells. A correlation between structural and optical properties has been found and discussed in detail.

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