Green Synthesis and Characterization of Gold Nanoparticles Using Lignin Nanoparticles

With the development of nanotechnology, gold nanoparticles (Au NPs) have attracted enormous attention due to their special properties. The green synthesis of Au NPs from lignin would inspire the utilization of lignin and its related functional materials. In this study, a rapid preparation process of Au NPs was investigated by utilizing lignin nanoparticles (LNPs) under room temperature without chemical addition. The LNPs acted as a reducing agent, stabilizing agent, and template for the preparation of LNPs@AuNPs. The obtained LNPs@AuNPs were characterized by UV-Vis spectrum, Transmission Electron Microscope (TEM), and X-ray photoelectron spectroscopy (XPS). The possible mechanism was illustrated by Fourier Transform Infrared Spectroscopy (FT-IR), 31P, XPS, and UV analyses. The abundant hydroxyl groups (24.96 mmol/g) favored the preparation of Au NPs. Au NPs diameters of 10–30 nm were well dispersed in the LNPs. The optimal reaction conditions were a ratio of 10 mg of LNPs to 0.05 mmol HAuCl4, room temperature, and a reaction time of 30 min. The LNPs@AuNPs exhibited excellent stability in the suspension for more than seven days. The reduction process could be related to the disruption of side chains of lignin, hydroxyl group oxidation, and hydroquinones and quinones from the comproportionation reaction. The LNPs@AuNPs would open a door for the design of Au NP/lignin-derived novel functional materials.

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Tuning the Magnetism of Gold Nanoparticles by Changing the Thiol Coating

10.26434/chemrxiv.12693149.v1 ◽

2020 ◽

Author(s):

Pengcheng Dong ◽

Elizabeth A. Fisher ◽

Maria-Victoria Meli ◽

Simon Trudel

Keyword(s):

Gold Nanoparticles ◽

Photoelectron Spectroscopy ◽

Quantum Interference ◽

Room Temperature ◽

Ultraviolet Photoelectron Spectroscopy ◽

Squid Magnetometry ◽

Superconducting Quantum Interference Device ◽

Temperature Behaviour ◽

Au Nps ◽

End Groups

<div>Room-temperature ferromagnetic behaviour has been reported in nanoscaled materials excepted to be diamagnetic, including gold. However, it is yet unclear which factors (size, shape, surface coating) predominantly influence the magnitude of the magnetic response. In this work, we study the magnetic and electronic properties of similarly-sized gold nanoparticles (Au NPs) coated with four different n-alkanethiols, as well as hydroxyl- and carboxyl-functionalized alkanethiols using superconducting quantum interference device (SQUID) magnetometry and ultraviolet photoelectron spectroscopy (UPS). We find room-temperature behaviour (hysteresis in magnetization vs field strength loops) in all samples, as well as large effective magnetic anisotropy. Importantly, we find the nanoparticles coated with polar chain end-groups (-OH and -COOH) show markedly higher magnetization; this increased magnetization correlates with a higher work function. This work establishes chemical handles to enhance magnetism in nanoscale gold particles.</div>

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Tuning the Magnetism of Gold Nanoparticles by Changing the Thiol Coating

10.26434/chemrxiv.12693149 ◽

2020 ◽

Author(s):

Pengcheng Dong ◽

Elizabeth A. Fisher ◽

Maria-Victoria Meli ◽

Simon Trudel

Keyword(s):

Gold Nanoparticles ◽

Photoelectron Spectroscopy ◽

Quantum Interference ◽

Room Temperature ◽

Ultraviolet Photoelectron Spectroscopy ◽

Squid Magnetometry ◽

Superconducting Quantum Interference Device ◽

Temperature Behaviour ◽

Au Nps ◽

End Groups

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Deposition of gold nanoparticles on organo-kaolinite — Application in electrocatalysis for carbon monoxide oxidation

Canadian Journal of Chemistry ◽

10.1139/v11-028 ◽

2011 ◽

Vol 89 (7) ◽

pp. 845-853 ◽

Cited By ~ 9

Author(s):

Sadok Letaief ◽

Wendy Pell ◽

Christian Detellier

Keyword(s):

Carbon Monoxide ◽

Gold Nanoparticles ◽

Photoelectron Spectroscopy ◽

Fine Particles ◽

Raw Materials ◽

Carbon Monoxide Oxidation ◽

Functional Materials ◽

Metallic State ◽

Oxidation Reactions ◽

X Ray

The clay mineral kaolinite was used as support of gold nanoparticles for heterogeneous catalysis of oxidation reactions, particularly of carbon monoxide oxidation. The application of clay minerals in the preparation of new functional materials provides an alternative approach for the use of these abundant raw materials. To improve the physicochemical properties of kaolinite, as well as to ensure a strong immobilization of the adsorbed species, kaolinite was functionalized by grafting 2-amino-2-methyl-1,3-propanediol on the internal and external surfaces of the octahedral sheets by reaction with the aluminol groups. Gold nanoparticles were then deposited on the external surfaces of the fine particles of the functionalized kaolinite. The resulting gold kaolinite nanohybrid material was characterized by various physicochemical techniques. X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, and energy-dispersive X-ray spectrometry confirmed that gold was effectively reduced to the metallic state during adsorption onto the external surfaces of the modified kaolinite. The gold nanoparticles have a narrow size distribution: more than 88% are less than 4 nm in diameter. Gold nanoparticles deposited on kaolinite catalyze the electro-oxidation of carbon monoxide in alkaline solution at room temperature.

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Methylation of Phenolic Hydroxyl Group and Demethylation of Anisoles

Journal of Chemical Research ◽

10.3184/030823409x431328 ◽

2009 ◽

Vol 2009 (4) ◽

pp. 229-230 ◽

Cited By ~ 1

Author(s):

Nobuhiro Sato ◽

Hiroyuki Endo

Keyword(s):

Microwave Heating ◽

Room Temperature ◽

Reverse Reaction ◽

Phenolic Hydroxyl ◽

Hydroxyl Group ◽

Hydroxyl Groups ◽

Phenolic Hydroxyl Groups ◽

Phenyl Ethers ◽

Methyl Phenyl

A mild methylation of phenolic hydroxyl groups with iodomethane was enabled in the presence of sodium bis(trimethylsilyl)amide at room temperature. The reverse reaction, namely demethylation of methyl phenyl ethers, was easily achieved by microwave heating with neat iodotrimethylsilane.

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Study of Antioxidant Property of the Rhizome Extract of Polygonatum cirrhifolium (Mahameda) and its use in the green synthesis of Gold nanoparticles

Prayogik Rasayan ◽

10.53023/p.rasayan-20161008 ◽

2017 ◽

Vol 1 (2) ◽

Author(s):

Braja Gopal Bag ◽

Shib Shankar Dash ◽

Anup Mandal

Keyword(s):

Gold Nanoparticles ◽

Green Synthesis ◽

Room Temperature ◽

Chemical Constituents ◽

Antioxidant Property ◽

Dpph Radical ◽

Mild Conditions ◽

One Step ◽

The One

The antioxidant efficacy of the rhizome extract of Polygonatum cirrhifolium (Mahameda) has been studied against a stable 2, 2-diphenylpicrylhydrazyl (DPPH) radical at room temperature. The chemical constituents present in the rhizome extract have been utilized for the one step synthesis of stable gold nanoparticles at room temperature under very mild conditions.

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Comparison of fabrication methods for the effective loading of Ag onto PVA nanofibers

Textile Research Journal ◽

10.1177/0040517517753635 ◽

2018 ◽

Vol 89 (4) ◽

pp. 625-634 ◽

Cited By ~ 12

Author(s):

Davood Kharaghani ◽

Hoik Lee ◽

Takahiro Ishikawa ◽

Tomoki Nagaishi ◽

Seong Hun Kim ◽

...

Keyword(s):

Electron Microscopy ◽

Photoelectron Spectroscopy ◽

Ag Nanoparticles ◽

Inductively Coupled Plasma ◽

Composite Nanofibers ◽

Reduction Method ◽

Reduction Process ◽

Hydroxyl Group ◽

Immersion Method ◽

Ag Particles

We investigated and compared three different methods for synthesizing Ag/PVA nanofibers by effectively dispersing and loading Ag particles onto PVA nanofibers and preventing the detachment of Ag from the nanofibers. The three methods were: (a) the solution reduction method (Method 1) in which the reduction of Ag+ was conducted before electrospinning, resulting in mixing the polymer and the Ag nanoparticles in the electrospinning solution; (b) the immersion method (Method 2) in which electrospun PVA nanofibers were immersed in the Ag+ solution, resulting in loading the Ag particles onto the PVA nanofibers; and (c) the nanofiber reduction method (Method 3) in which the Ag+/PVA solution underwent electrospinning followed by the reduction process with Ag+/PVA nanofibers. All of the electrospun nanofibers had a crosslinked structure that resulted from the chemical reaction of glutaraldehyde with the hydroxyl group of PVA, to prevent dissolution in the aqueous solution. Fourier transform infrared spectra provided evidence of the successful formation of the crosslinked structure of the nanofibers, and x-ray photoelectron spectroscopy and transmission electron microscopy confirmed the loading of Ag nanoparticles onto the nanofibers. The release profiles were investigated by inductively coupled plasma, and the morphology of the nanofibers was observed by scanning electron microscopy. Method 3 had the best performances for loading Ag particles onto the nanofibers and for minimizing the loss of Ag nanoparticles from the nanofibers. These findings identified an effective method for fabricating metal/polymer composite nanofibers, and will allow the expansion of the applications of metal/polymeric composite nanofibers.

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Green Synthesis of Gold Nanoparticles Using Longan Polysaccharide and their Reduction of 4-nitrophenol and Biological Applications

NANO ◽

10.1142/s1793292020500022 ◽

2020 ◽

Vol 15 (01) ◽

pp. 2050002 ◽

Cited By ~ 6

Author(s):

Xiaoyu Zhang ◽

Liyuan Fan ◽

Yanshuai Cui ◽

Tianming Cui ◽

Shengfu Chen ◽

...

Keyword(s):

Gold Nanoparticles ◽

Green Synthesis ◽

Metallic Nanoparticles ◽

High Catalytic Activity ◽

Synthetic Method ◽

Biological Applications ◽

Au Nps ◽

Stabilizing Agents ◽

Highly Dispersed ◽

Negative Zeta Potential

The green synthesis of gold nanoparticles (Au NPs) for catalytic and biological applications has been drawing great attention. To compare with plant extracts, the polysaccharides may be good reducing and stabilizing agents. In this work, we describe the preparation of longan polysaccharide stabilized gold nanoparticles (Aun-LP NPs) by reduction of gold ions using a green synthetic method. The formation of gold nanoparticles (Au NPs) was confirmed by UV-Vis spectra. TEM showed that Au NPs had a small size (7.8–15.6[Formula: see text]nm) and were highly dispersed without any aggregation. XPS confirmed that the surface elemental composition of Aun-LP NPs was C, O, and Au. DLS demonstrated that Aun-LP NPs had good stability and negative zeta potential. In addition, Aun-LP NPs had high catalytic activity for the reduction of 4-nitrophenol. More importantly, Aun-LP NPs had ignorable cytotoxicity towards HeLa cells and showed good antioxidant activity. Taken together, the results indicated that longan polysaccharide can be used as reducing agents and stabilizers for the preparation of metallic nanoparticles, and the product had wide applications.

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Preparation of Au nanoparticles by Anthemis xylopoda flowers aqueous extract and their application for alkyne/aldehyde/amine A3-type coupling reactions

RSC Advances ◽

10.1039/c5ra08927a ◽

2015 ◽

Vol 5 (57) ◽

pp. 46240-46246 ◽

Cited By ~ 58

Author(s):

Mahmoud Nasrollahzadeh ◽

S. Mohammad Sajadi

Keyword(s):

Gold Nanoparticles ◽

Green Synthesis ◽

Aqueous Extract ◽

Au Nanoparticles ◽

Coupling Reactions ◽

Au Nps ◽

Type Coupling

This paper reports on the green synthesis of gold nanoparticles (Au NPs) by Anthemis xylopoda flowers aqueous extract without the addition of surfactant agents and their application as stable catalysts for the synthesis of propargylamines.

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