Highly efficient and selective hydrogenation of chloronitrobenzenes to chloroanilines by H2 over confined silver nanoparticles

RSC Advances ◽  
2016 ◽  
Vol 6 (38) ◽  
pp. 31871-31875 ◽  
Author(s):  
Lini Yang ◽  
Lina Xing ◽  
Cunxia Cheng ◽  
Lixin Xia ◽  
Hongyang Liu
Keyword(s):  
Silver Nanoparticles ◽  
Selective Hydrogenation ◽  
Good Activity ◽  
Ag Nps ◽  
Highly Efficient ◽  
Ag Catalysts

The Ag NPs with sizes ranging form 5–6 nm confined into SBA-15 show a very good activity and robust recycle ability for hydrogenation of chloronitrobenzenes to the corresponding chloroanilines by H2, comparing with that of the traditional SiO2 supported Ag catalysts.

scholarly journals Extracellular probiotic lipase capped silver nanoparticles as highly efficient broad spectrum antimicrobial agents

RSC Advances ◽  
2018 ◽  
Vol 8 (55) ◽  
pp. 31358-31365 ◽  
Author(s):  
Imran Khan ◽  
Nivetha Sivasankaran ◽  
Ravikiran Nagarjuna ◽  
Ramakrishnan Ganesan ◽  
Jayati Ray Dutta
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Broad Spectrum ◽  
Antimicrobial Agents ◽  
Ag Nps ◽  
Highly Efficient

A series of Ag NPs capped with different concentrations of probiotic lipase have been synthesized. The obtained Ag NPs exhibited efficient broad spectrum antimicrobial activity at concentrations much lower than the LC50values of zebrafish.

scholarly journals Single-Step Green Synthesis of Highly Concentrated and Stable Colloidal Dispersion of Core-Shell Silver Nanoparticles and Their Antimicrobial and Ultra-High Catalytic Properties

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1007
Author(s):  
Azam Ali ◽  
Mariyam Sattar ◽  
Fiaz Hussain ◽  
Muhammad Humble Khalid Tareen ◽  
Jiri Militky ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Tannic Acid ◽  
Rate Constant ◽  
Catalytic Properties ◽  
Colloidal Dispersion ◽  
Alkaline Condition ◽  
Core Shell ◽  
Average Particle ◽  
Ag Nps

The versatile one-pot green synthesis of a highly concentrated and stable colloidal dispersion of silver nanoparticles (Ag NPs) was carried out using the self-assembled tannic acid without using any other hazardous chemicals. Tannic acid (Plant-based polyphenol) was used as a reducing and stabilizing agent for silver nitrate in a mild alkaline condition. The synthesized Ag NPs were characterized for their concentration, capping, size distribution, and shape. The experimental results confirmed the successful synthesis of nearly spherical and highly concentrated (2281 ppm) Ag NPs, capped with poly-tannic acid (Ag NPs-PTA). The average particle size of Ag NPs-PTA was found to be 9.90 ± 1.60 nm. The colloidal dispersion of synthesized nanoparticles was observed to be stable for more than 15 months in the ambient environment (25 °C, 65% relative humidity). The synthesized AgNPs-PTA showed an effective antimicrobial activity against Staphylococcus Aureus (ZOI 3.0 mM) and Escherichia coli (ZOI 3.5 mM). Ag NPs-PTA also exhibited enhanced catalytic properties. It reduces 4-nitrophenol into 4-aminophenol in the presence of NaBH4 with a normalized rate constant (Knor = K/m) of 615.04 mL·s−1·mg−1. For comparison, bare Ag NPs show catalytic activity with a normalized rate constant of 139.78 mL·s−1·mg−1. Furthermore, AgNPs-PTA were stable for more than 15 months under ambient conditions. The ultra-high catalytic and good antimicrobial properties can be attributed to the fine size and good aqueous stability of Ag NPs-PTA. The unique core-shell structure and ease of synthesis render the synthesized nanoparticles superior to others, with potential for large-scale applications, especially in the field of catalysis and medical.

scholarly journals Antibacterial activity of royal jelly-mediated green synthesized silver nanoparticles

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Susanna Gevorgyan ◽  
Robin Schubert ◽  
Mkrtich Yeranosyan ◽  
Lilit Gabrielyan ◽  
Armen Trchounian ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Green Synthesis ◽  
Royal Jelly ◽  
Fluorescence Emission ◽  
Spherical Particles ◽  
Ag Nps ◽  
Gram Negative ◽  
Green Synthesized Silver Nanoparticles ◽  
Higher Sensitivity

AbstractThe application of green synthesis in nanotechnology is growing day by day. It’s a safe and eco-friendly alternative to conventional methods. The current research aimed to study raw royal jelly’s potential in the green synthesis of silver nanoparticles and their antibacterial activity. Royal jelly served as a reducing and oxidizing agent in the green synthesis technology of colloidal silver nanoparticles. The UV–Vis maximum absorption at ~ 430 nm and fluorescence emission peaks at ~ 487 nm confirmed the presence of Ag NPs. Morphology and structural properties of Ag NPs and the effect of ultrasound studies revealed: (i) the formation of polydispersed and spherical particles with different sizes; (ii) size reduction and homogeneity increase by ultrasound treatment. Antibacterial activity of different concentrations of green synthesized Ag NPs has been assessed on Gram-negative S. typhimurium and Gram-positive S. aureus, revealing higher sensitivity on Gram-negative bacteria.

scholarly journals Toxicity and chemical transformation of silver nanoparticles in A549 lung cells: dose-rate-dependent genotoxic impact

2021 ◽  
Author(s):  
Laure Bobyk ◽  
Adeline Tarantini ◽  
David Beal ◽  
Giulia Veronesi ◽  
Isabelle Kieffer ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Silver Nanoparticles ◽  
Dose Rate ◽  
Cell Metabolism ◽  
A549 Cells ◽  
Dna Integrity ◽  
Lung Cells ◽  
Ag Nps ◽  
Rate Dependent ◽  
A549 Lung

Acute exposure of A549 cells to Ag-NPs induces stronger effects on DNA integrity, ROS level, cell metabolism and cell cycle than repeated exposure. Ag-NPs dissolves in both exposure conditions and Ag ions recombine with thiolated proteins.

Highly Efficient Ir–CoOx Hybrid Nanostructures for the Selective Hydrogenation of Furfural to Furfuryl Alcohol

Langmuir ◽  
2021 ◽  
Vol 37 (5) ◽  
pp. 1894-1901
Author(s):  
Hongbo Yu ◽  
Jihao Zhao ◽  
Chunzheng Wu ◽  
Bo Yan ◽  
Shuangliang Zhao ◽  
...  
Keyword(s):  
Selective Hydrogenation ◽  
Furfuryl Alcohol ◽  
Hybrid Nanostructures ◽  
Highly Efficient

scholarly journals Green synthesis of silver nanoparticles: Characterization and its potential biomedical applications

2021 ◽  
Vol 10 (1) ◽  
pp. 412-420
Author(s):  
Mona S. Alwhibi ◽  
Dina A. Soliman ◽  
Manal A. Awad ◽  
Asma B. Alangery ◽  
Horiah Al Dehaish ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Aloe Vera ◽  
Inhibition Zone ◽  
Biologically Active ◽  
Noble Metal Nanoparticles ◽  
Biological Synthesis ◽  
Ag Nps ◽  
Mouse Melanoma ◽  
Therapeutic Benefits ◽  
Vis Spectroscopy

Abstract In recent times, research on the synthesis of noble metal nanoparticles (NPs) has developed rapidly and attracted considerable attention. The use of plant extracts is the preferred mode for the biological synthesis of NPs due to the presence of biologically active constituents. Aloe vera is a plant endowed with therapeutic benefits especially in skincare due to its unique curative properties. The present study focused on an environmental friendly and rapid method of phytosynthesis of silver nanoparticles (Ag-NPs) using A. vera gel extract as a reductant. The synthesized Ag-NPs were characterized by transmission electron microscopy (TEM), UV-Vis spectroscopy, Fourier transform infrared (FTIR), and dynamic light scattering (DLS). TEM micrographs showed spherical-shaped synthesized Ag-NPs with a diameter of 50–100 nm. The UV-Vis spectrum displayed a broad absorption peak of surface plasmon resonance (SPR) at 450 nm. The mean size and size distribution of the formed Ag-NPs were investigated using the DLS technique. Antibacterial studies revealed zones of inhibition by Ag-NPs of A. vera (9 and 7 mm) against Pseudomonas aeruginosa and Escherichia coli, respectively. Furthermore, the antifungal activity was screened, based on the diameter of the growth inhibition zone using the synthesized Ag-NPs for different fungal strains. Anticancer activity of the synthesized Ag-NPs against the mouse melanoma F10B16 cell line revealed 100% inhibition with Ag-NPs at a concentration of 100 µg mL−1. The phytosynthesized Ag-NPs demonstrated a marked antimicrobial activity and also exhibited a potent cytotoxic effect against mouse melanoma F10B16 cells. The key findings of this study indicate that synthesized Ag-NPs exhibit profound therapeutic activity and could be potentially ideal alternatives in medicinal applications.

scholarly journals Size Control of Synthesized Silver Nanoparticles by Simultaneous Chemical Reduction and Laser Fragmentation in Origanum majorana Extract: Antibacterial Application

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2326
Author(s):  
Entesar Ali Ganash ◽  
Reem Mohammad Altuwirqi
Keyword(s):  
Silver Nanoparticles ◽  
Irradiation Time ◽  
Chemical Reduction ◽  
Size Control ◽  
Reduction Process ◽  
Laser Wavelength ◽  
X Ray Diffraction ◽  
Ag Nps ◽  
Transmission Electron ◽  
Origanum Majorana

In this work, silver nanoparticles (Ag NPs) were synthesized using a chemical reduction approach and a pulsed laser fragmentation in liquid (PLFL) technique, simultaneously. A laser wavelength of 532 nm was focused on the as produced Ag NPs, suspended in an Origanum majorana extract solution, with the aim of controlling their size. The effect of liquid medium concentration and irradiation time on the properties of the fabricated NPs was studied. While the X-ray diffraction (XRD) pattern confirmed the existence of Ag NPs, the UV–Vis spectrophotometry showed a significant absorption peak at about 420 nm, which is attributed to the characteristic surface plasmon resonance (SPR) peak of the obtained Ag NPs. By increasing the irradiation time and the Origanum majora extract concentration, the SPR peak shifted toward a shorter wavelength. This shift indicates a reduction in the NPs’ size. The effect of PLFL on size reduction was clearly revealed from the transmission electron microscopy images. The PLFL technique, depending on experimental parameters, reduced the size of the obtained Ag NPs to less than 10 nm. The mean zeta potential of the fabricated Ag NPs was found to be greater than −30 mV, signifying their stability. The Ag NPs were also found to effectively inhibit bacterial activity. The PLFL technique has proved to be a powerful method for controlling the size of NPs when it is simultaneously associated with a chemical reduction process.

scholarly journals Reactivity and Chemical Sintering of Carey Lea Silver Nanoparticles

Nanomaterials ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1525
Author(s):  
Sergey Vorobyev ◽  
Elena Vishnyakova ◽  
Maxim Likhatski ◽  
Alexander Romanchenko ◽  
Ivan Nemtsev ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Silver Nanoparticles ◽  
Flexible Electronics ◽  
Photoelectron Spectroscopy ◽  
Colloidal Solutions ◽  
Ag Nps ◽  
Wide Range ◽  
Carboxylic Groups ◽  
The Media ◽  
Sulfide Ions

Carey Lea silver hydrosol is a rare example of very concentrated colloidal solutions produced with citrate as only protective ligands, and prospective for a wide range of applications, whose properties have been insufficiently studied up to now. Herein, the reactivity of the immobilized silver nanoparticles toward oxidation, sulfidation, and sintering upon their interaction with hydrogen peroxide, sulfide ions, and chlorocomplexes of Au(III), Pd(II), and Pt(IV) was investigated using SEM and X-ray photoelectron spectroscopy (XPS). The reactions decreased the number of carboxylic groups of the citrate-derived capping and promoted coalescence of 7 nm Ag NPs into about 40 nm ones, excluding the interaction with hydrogen peroxide. The increased nanoparticles form loose submicrometer aggregates in the case of sulfide treatment, raspberry-like micrometer porous particles in the media containing Pd(II) chloride, and densely sintered particles in the reaction with inert H2PtCl6 complexes, probably via the formation of surface Ag-Pt alloys. The exposure of Ag NPs to HAuCl4 solution produced compact Ag films along with nanocrystals of Au metal and minor Ag and AgCl. The results are promising for chemical ambient temperature sintering and rendering silver-based nanomaterials, for example, for flexible electronics, catalysis, and other applications.

scholarly journals Preparation of Silver Nanoparticles and Their Industrial and Biomedical Applications: A Comprehensive Review

2015 ◽  
Vol 2015 ◽  
pp. 1-16 ◽  
Author(s):  
Adnan Haider ◽  
Inn-Kyu Kang
Keyword(s):  
Silver Nanoparticles ◽  
Biomedical Applications ◽  
Consumer Products ◽  
Ag Nps ◽  
New Techniques ◽  
Governing Factor ◽  
Wide Range ◽  
Microbial Proliferation ◽  
Synthetic Routes ◽  
Biomedical Fields

Silver nanoparticles (Ag-NPs) have diverted the attention of the scientific community and industrialist itself due to their wide range of applications in industry for the preparation of consumer products and highly accepted application in biomedical fields (especially their efficacy against microbes, anti-inflammatory effects, and wound healing ability). The governing factor for their potent efficacy against microbes is considered to be the various mechanisms enabling it to prevent microbial proliferation and their infections. Furthermore a number of new techniques have been developed to synthesize Ag-NPs with controlled size and geometry. In this review, various synthetic routes adapted for the preparation of the Ag-NPs, the mechanisms involved in its antimicrobial activity, its importance/application in commercial as well as biomedical fields, and possible application in future have been discussed in detail.

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