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 ◽  
...  

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.

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1777 ◽  
Author(s):  
Md. Mahiuddin ◽  
Prianka Saha ◽  
Bungo Ochiai

A green synthesis of silver nanoparticles (AgNPs) was conducted using the stem extract of Piper chaba, which is a plant abundantly growing in South and Southeast Asia. The synthesis was carried out at different reaction conditions, i.e., reaction temperature, concentrations of the extract and silver nitrate, reaction time, and pH. The synthesized AgNPs were characterized by visual observation, ultraviolet–visible (UV-vis) spectroscopy, dynamic light scattering (DLS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), x-ray diffraction (XRD), energy dispersive x-ray (EDX), and Fourier transform infrared (FTIR) spectroscopy. The characterization results revealed that AgNPs were uniformly dispersed and exhibited a moderate size distribution. They were mostly spherical crystals with face-centered cubic structures and an average size of 19 nm. The FTIR spectroscopy and DLS analysis indicated that the phytochemicals capping the surface of AgNPs stabilize the dispersion through anionic repulsion. The synthesized AgNPs effectively catalyzed the reduction of 4-nitrophenol (4-NP) and degradation of methylene blue (MB) in the presence of sodium borohydride.


Author(s):  
Qing Feng Wang ◽  
Peng Cheng Zhang ◽  
Xiao Hong Wang ◽  
Da Peng Ren ◽  
Ding Mu Lang ◽  
...  

Microstructure of nickel deposit ,which was prepared with pulse-plating technology on depleted uranium surface, has been studied by X-ray diffractometry(XRD),Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). The results indicate that the crystallographic structure of the deposit is face centered cubic; the deposit has a highly preferred orientation of (200), the relative orientation density of (200) is 3.44; the average grain size is about 45.5nm. The deposit is fine and has multi-crystal nature as well as crystallographic defects as dislocation, stacking and twin. It’s feasible to prepare nanocrystalline nickel deposit on depleted uranium surface with pulse plating technology.


2021 ◽  
Vol 19 (2) ◽  
pp. 25-32
Author(s):  
Deegendra Khadka ◽  
Rachana Regmi ◽  
Mitesh Shrestha ◽  
Megha Raj Banjara

The application of silver nanoparticles in various sectors including health related field is remarkably profound. Nowadays, the research of synthesizing metal nanoparticles (MNPs) using plant extracts is fascinating field as it offers the eco-friendly and cost-effective method for nanoparticle synthesis. In this study, we synthesized silver nanoparticles (AgNPs) using methanolic extract of B.asiatica and C. fistula regarding their ethnomedical importance. The synthesized AgNPs were characterized by UV-Visible spectroscopy, Fourier transform infrared spectroscopy (FTIR) and X-ray diffractometer (XRD). UV-vis spectroscopy exhibited the characteristic Surface Plasmon Peak of silver nanoparticle~420 nm.FTIR data were measured to get a preliminary idea on the functional groups responsible for the stabilization of AgNPs. XRD data confirmed the natural crystal structure with a face centered cubic of AgNPs. The antibacterial activity of biosynthesized AgNPs was assessed by testing promptly available gram-positive Staphylococcus aureus and gram-negative Escherichia coli bacterial strain and antioxidant activity was calculated by DPPH assay. The overall outcomes of the studies concluded that the application of the biogenic synthesis of AgNPs of B. asiaticaas an antioxidant and antibacterial agent is more potent showing IC50 value 65.1±1.30 μg/mL and the highest zone of inhibition 15 mm in diameter against S. aureus.


2016 ◽  
Vol 1141 ◽  
pp. 65-71 ◽  
Author(s):  
M.P. Deshpande ◽  
Kiran N. Patel ◽  
Vivek P. Gujarati ◽  
Kamakshi Patel ◽  
S.H. Chaki

Nanocrystalline NiO has been prepared successfully by chemical precipitation route using nickel nitrate hexahydrate (Ni (NO3)2·6H2O) and sodium hydroxide (NaOH) aqueous solution at a temperature of 60 ̊C. Their compositional, structural, morphological, thermal and optical properties were studied using energy dispersive analysis of X-rays (EDAX), X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), ultraviolet-visible (UV-Vis) spectroscopy, photoluminescence (PL) spectroscopy and Raman spectroscopy. From XRD pattern we confirmed the face centered cubic (fcc) structure of the synthesized NiO nanoparticles. The selected area electron diffraction (SAED) pattern indicated the same crystalline planes as seen in XRD pattern. TGA indicates good thermal stability of synthesized NiO nanoparticles and the optical absorption spectrum of NiO nanoparticles shows the strong absorption edge at 235nm (4.10eV). PL spectra of NiO nanoparticles shows two wide emission peaks at 420nm (2.95eV) and 440nm (2.82eV) and a strong–broad peak at 460nm (2.70eV) in violet emission band whereas the Raman peak observed at 518cm-1 shows the Ni-O stretching mode of vibration.


1992 ◽  
Vol 7 (8) ◽  
pp. 1973-1975 ◽  
Author(s):  
J.W. Hoehn ◽  
T. Foecke ◽  
W.W. Gerberich

Cracks of up to 40 μm which are either transgranular cleavage or very low energy “ductile” cracks have been introduced into large-grained fcc Ni. The mechanism for introducing this brittle fracture was dynamic indentation. Optical and scanning electron microscopy together with use of selected area channeling patterns were used to confirm that the fracture process is transgranular. The results qualitatively support the hypothesis that dynamic cracks originating in a brittle film can propagate relatively large distances into a ductile face-centered-cubic substrate by a rapid, low energy process.


1997 ◽  
Vol 3 (S2) ◽  
pp. 413-414
Author(s):  
E.M. Hunt ◽  
J.M. Hampikian ◽  
N.D. Evans

Ion implantation can be used to alter the optical response of insulators through the formation of embedded nano-sized particles. Single crystal alumina has been implanted at ambient temperature with 50 keV Ca+ to a fluence of 5 x 1016 ions/cm2. Ion channeling, Knoop microhardness measurements, and transmission electron microscopy (TEM) indicate that the alumina surface layer was amorphized by the implant. TEM also revealed nano-sized crystals ≈7 - 8 nm in diameter as seen in Figure 1. These nanocrystals are randomly oriented, and exhibit a face-centered cubic structure (FCC) with a lattice parameter of 0.409 nm ± 0.002 nm. The similarity between this crystallography and that of pure aluminum (which is FCC with a lattice parameter of 0.404 nm) suggests that they are metallic aluminum nanocrystals with a slightly dilated lattice parameter, possibly due to the incorporation of a small amount of calcium.Energy-filtered transmission electron microscopy (EFTEM) provides an avenue by which to confirm the metallic nature of the aluminum involved in the nanocrystals.


Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2382 ◽  
Author(s):  
Muhammad Jamshed Khan ◽  
Suriya Kumari ◽  
Kamyar Shameli ◽  
Jinap Selamat ◽  
Awis Qurni Sazili

Nanoparticles (NPs) are, frequently, being utilized in multi-dimensional enterprises. Silver nanoparticles (AgNPs) have attracted researchers in the last decade due to their exceptional efficacy at very low volume and stability at higher temperatures. Due to certain limitations of the chemical method of synthesis, AgNPs can be obtained by physical methods including sun rays, microwaves and ultraviolet (UV) radiation. In the current study, the synthesis of pullulan mediated silver nanoparticles (P-AgNPs) was achieved through ultraviolet (UV) irradiation, with a wavelength of 365 nm, for 96 h. P-AgNPs were formed after 24 h of UV-irradiation time and expressed spectra maxima as 415 nm, after 96 h, in UV-vis spectroscopy. The crystallographic structure was “face centered cubic (fcc)” as confirmed by powder X-ray diffraction (PXRD). Furthermore, high resolution transmission electron microscopy (HRTEM) proved that P-AgNPs were covered with a thin layer of pullulan, with a mean crystalline size of 6.02 ± 2.37. The average lattice fringe spacing of nanoparticles was confirmed as 0.235 nm with quasi-spherical characteristics, by selected area electron diffraction (SAED) analysis. These green synthesized P-AgNPs can be utilized efficiently, as an active food and meat preservative, when incorporated into the edible films.


2022 ◽  
Vol 210 ◽  
pp. 114461
Author(s):  
Fuzhou Han ◽  
Geping Li ◽  
Fusen Yuan ◽  
Yingdong Zhang ◽  
Wenbin Guo ◽  
...  

2019 ◽  
Vol 290 ◽  
pp. 87-92
Author(s):  
Adamu Ibrahim Usman ◽  
Azlan Abdul Aziz ◽  
Osama Abu Noqta

A simple method to synthesized nanoparticles was satisfied by reduction of tetrachloroauric acid in the presence of palm oil fronds extracts as capping and reduced agents. The as-synthesized gold nanoparticles structures have a triangular and hexagonal shape that are of tens of nanometre in size. It was realized that good control shape of nano-hexagonal gold nanoparticles were obtained from nano-triangular gold nanoparticles in the absence of any soft template. The production techniques of the gold nanoparticles were examined by using UV-vis spectroscopy, EFTEM and XRD patterns, which showed peaks at (111), (200), (220), (311) and (222), that described the preferential structure of the AuNPs as face-centered cubic crystal


1995 ◽  
Vol 10 (6) ◽  
pp. 1546-1554 ◽  
Author(s):  
G.M. Chow ◽  
L.K. Kurihara ◽  
K.M. Kemner ◽  
P.E. Schoen ◽  
W.T. Elam ◽  
...  

Nanocrystalline CoxCu100−x (4 ⋚ x ⋚ 49 at. %) powders were prepared by the reduction of metal acetates in a polyol. The structure of powders was characterized by x-ray diffraction (XRD), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), extended x-ray absorption fine structure (EXAFS) spectroscopy, solid-state nuclear magnetic resonance (NMR) spectroscopy, and vibrating sample magnetometry (VSM). As-synthesized powders were composites consisting of nanoscale crystallites of face-centered cubic (fcc) Cu and metastable face-centered cubic (fcc) Co. Complementary results of XRD, HRTEM, EXAFS, NMR, and VSM confirmed that there was no metastable alloying between Co and Cu. The NMR data also revealed that there was some hexagonal-closed-packed (hcp) Co in the samples. The powders were agglomerated, and consisted of aggregates of nanoscale crystallites of Co and Cu. Upon annealing, the powders with low Co contents showed an increase in both saturation magnetization and coercivity with increasing temperature. The results suggested that during preparation the nucleation of Cu occurred first, and the Cu crystallites served as nuclei for the formation of Co.


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