scholarly journals Bimetallic Nanoparticles Associating Noble Metals and First-Row Transition Metals in Catalysis

ACS Nano ◽  
2021 ◽  
Author(s):  
Irene Mustieles Marin ◽  
Juan M. Asensio ◽  
Bruno Chaudret
Keyword(s):  
Transition Metals ◽  
Noble Metals ◽  
Bimetallic Nanoparticles

scholarly journals Antibacterial Activity of Partially Oxidized Ag/Au Nanoparticles against the Oral PathogenPorphyromonas gingivalisW83

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Megan S. Holden ◽  
Jason Black ◽  
Ainsely Lewis ◽  
Marie-Claire Boutrin ◽  
Elvin Walemba ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Periodontal Disease ◽  
Noble Metals ◽  
Bimetallic Nanoparticles ◽  
Periodontal Pocket ◽  
Dissolution Behavior ◽  
Galvanic Replacement ◽  
Chloroauric Acid ◽  
Ag Nps ◽  
Silver Dissolution

Advances in nanotechnology provide opportunities for the prevention and treatment of periodontal disease. While physicochemical properties of Ag containing nanoparticles (NPs) are known to influence the magnitude of their toxicity, it is thought that nanosilver can be made less toxic to eukaryotes by passivation of the NPs with a benign metal. Moreover, the addition of other noble metals to silver nanoparticles, in the alloy formulation, is known to alter the silver dissolution behavior. Thus, we synthesized glutathione capped Ag/Au alloy bimetallic nanoparticles (NPs)viathe galvanic replacement reaction between maltose coated Ag NPs and chloroauric acid (HAuCl4) in 5% aqueous triblock F127 copolymer solution. We then compared the antibacterial activity of the Ag/Au NPs to pure Ag NPs onPorphyromonas gingivalisW83, a key pathogen in the development of periodontal disease. Only partially oxidized glutathione capped Ag and Ag/Au (Au : Ag ≈ 0.2) NPs inhibited the planktonic growth ofP. gingivalisW83. This effect was enhanced in the presence of hydrogen peroxide, which simulates the oxidative stress environment in the periodontal pocket during chronic inflammation.

scholarly journals Lightning-Rod Effect of Plasmonic Field Enhancement on Hydrogen-Absorbing Transition Metals

Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1235 ◽  
Author(s):  
Norihiko Fukuoka ◽  
Katsuaki Tanabe
Keyword(s):  
Transition Metals ◽  
Metal Surfaces ◽  
Noble Metals ◽  
Field Enhancement ◽  
Operating Conditions ◽  
Optical Systems ◽  
Field Energy ◽  
Enhancement Effect ◽  
Morphological Aspect ◽  
Aspect Ratios

The plasmonic enhancement of electromagnetic field energy density at the sharp tips of nanoparticles or nanoscale surface roughnesses of hydrogen-absorbing transition metals, Pd, Ti, and Ni, is quantitatively investigated. A large degree of energy focusing is observed for these transition metals in the microwave region, even surpassing the enhancement for noble metals according to the conditions. Pd, for instance, exhibits peak field enhancement factors of 6000 and 2 × 108 in air for morphological aspect ratios of 10 and 100, respectively. Metal surfaces possibly contain such degrees of nano- or micro-scale native random roughnesses, and, therefore, the field enhancement effect may have been unknowingly produced in existing electrical and optical systems. In addition, for future devices under development, particularly in hydrogen-related applications, it is desirable to design and optimize the systems, including the choice of materials, structures, and operating conditions, by accounting for the plasmonic local energy enhancement effect around the metal surfaces.

Effective Interionic Potentials and Properties of Molten Noble and Transition Metals

1975 ◽  
Vol 30 (4) ◽  
pp. 485-491 ◽  
Author(s):  
Y. Waseda ◽  
M. Ohtani
Keyword(s):  
Transition Metals ◽  
Noble Metals ◽  
Distribution Functions ◽  
Molten Metals ◽  
X Ray Diffraction ◽  
Self Diffusion ◽  
Pseudopotential Calculations ◽  
Poten Tials ◽  
Effective Valence ◽  
Valence Number

Abstract Recent X-ray diffraction data on molten noble and transition metals have been used to calculate effective interionic potentials by means of the Born-Green equation. The results on the noble metals are compared with the generalized pseudopotential calculations of Moriarty. In all cases the potentions were found to be insensitive to temperature and to have long-range oscillations. The results suggest that the effective valence number is close to unity in these molten metals, this giving reasonable values of the electrical resistivity when calculated in the framework of the usual Ziman theory.The self-diffusion coefficients, viscosities and surface tensions were calculated from the poten-tials and radial distribution functions using the kinetic theory of fluids. Adequate agreement with experimental data was obtained.

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