scholarly journals Influence of negative charge on the optical properties of a silver sol

2000 ◽  
Vol 65 (3) ◽  
pp. 195-200 ◽  
Author(s):  
Vesna Vodnik ◽  
Jovan Nedeljkovic
Keyword(s):  
Optical Properties ◽  
Absorption Band ◽  
Sodium Borohydride ◽  
Negative Charge ◽  
Silver Particles ◽  
Intermediate Species ◽  
Free Electrons ◽  
Plasmon Absorption Band ◽  
Metal Catalyzed ◽  
Hydrolysis Of

The effects of negative charge on the optical properties of a silver sol prepared using sodium borohydride as a reductant were studied. The oscillations in the position of the maximum and the intensity of the surface plasmon absorption band were observed. The observed effects were explained as a consequence of the fluctuation of the density of free electrons due to the alternate charging and discharging of the silver particles. The charging process involves electron injection from borohydride ions and intermediate species formed during the course of the metal-catalyzed hydrolysis of borohydride ions (BH3OH-, BH2(OH)2 - and BH(OH)3 - ) into the silver particles, while discharge of the silver sol, by reduction of water to hydrogen, limits the attainable negative charge on the particles.

Optical properties of nanosized gold particles

1996 ◽  
Vol 11 (11) ◽  
pp. 2834-2840 ◽  
Author(s):  
Robert H. Doremus ◽  
Pratima Rao
Keyword(s):  
Particle Size ◽  
Optical Properties ◽  
Absorption Spectrum ◽  
Absorption Band ◽  
Small Particle ◽  
Small Particle Size ◽  
Free Electrons ◽  
Gold Particles ◽  
Plasma Absorption ◽  
Good Agreement

Gold particles smaller than 2 nm in diameter were grown in glass. Their optical absorption spectrum did not show the usual plasma absorption band for gold particles; this band was spread by the small particle size. The absorption spectrum was calculated from the bulk optical properties of gold, modified for the small particle size; there was good agreement between calculated and measured spectra. The smallest particles containing from 20 to 40 gold atoms showed a λ−4 dependence of absorption on wavelength λ. This result implies that the absorption in these particles was entirely from free electrons at wavelengths above 0.3 μm.

Hydrogen generation from hydrolysis of sodium borohydride using Ni–Ru nanocomposite as catalysts

2009 ◽  
Vol 34 (5) ◽  
pp. 2153-2163 ◽  
Author(s):  
Cheng-Hong Liu ◽  
Bing-Hung Chen ◽  
Chan-Li Hsueh ◽  
Jie-Ren Ku ◽  
Ming-Shan Jeng ◽  
...  
Keyword(s):  
Sodium Borohydride ◽  
Hydrogen Generation ◽  
Hydrolysis Of

Novel high dispersion and high stability cobalt-inlaid carbon sphere catalyst for hydrogen generation from the hydrolysis of sodium borohydride

Fuel ◽  
2022 ◽  
Vol 310 ◽  
pp. 122276
Author(s):  
Lei Sun ◽  
Yuanyuan Meng ◽  
Xinxin Kong ◽  
Huiyun Ge ◽  
Xingman Chen ◽  
...  
Keyword(s):  
Sodium Borohydride ◽  
High Stability ◽  
Hydrogen Generation ◽  
High Dispersion ◽  
Carbon Sphere ◽  
Hydrolysis Of

Synthesis of MOF-derived Co@C composites and application for efficient hydrolysis of sodium borohydride

2019 ◽  
Vol 469 ◽  
pp. 764-769 ◽  
Author(s):  
Xinyan Zhang ◽  
Xiaowei Sun ◽  
Dongyan Xu ◽  
Xumei Tao ◽  
Ping Dai ◽  
...  
Keyword(s):  
Sodium Borohydride ◽  
Hydrolysis Of

DC Polarographic and Spectrophotometric Determination of Ampicillin Capsules

1980 ◽  
Vol 63 (5) ◽  
pp. 1049-1051
Author(s):  
Juan A Squella ◽  
Luis J Nunez-Vergara ◽  
Maximo Aros
Keyword(s):  
Absorption Band ◽  
Spectrophotometric Determination ◽  
Degradation Product ◽  
Uv Absorption ◽  
Acidic Hydrolysis ◽  
Average Recovery ◽  
Polarographic Wave ◽  
Spectrophotometric Methods ◽  
Hydrolysis Of

Abstract Polarographic and spectrophotometric methods are proposed for the determination of ampicillin in capsules. Acidic hydrolysis of ampicillin with 1% HCHO in 0.3N HCl yields a degradation product identified as 2-hydroxy-3-phenyl-6-methylpyrazine. This compound has a well defined UV absorption band at 380 nm and a polarographic wave at –0.55 V vs SCE, which can be used for analytical purposes. Individual capsule assays, composite assays, and recovery studies are described. The average recovery values and standard deviations (SD) for UV and polarographic determinations were 99.20% (SD 0.95) and 100.85% (SD 1.09), respectively

scholarly journals Unconventional Optical Response in Engineered Au-Ag Nanostructures

2019 ◽  
Author(s):  
Dev Kumar Thapa ◽  
Subham Kumar Saha ◽  
Guru Pratheep Rajasekar ◽  
Biswajit Bhattacharyya ◽  
Rekha Mahadevu ◽  
...  
Keyword(s):  
Optical Properties ◽  
Surface Plasmon ◽  
Mie Theory ◽  
Localized Surface Plasmon ◽  
Silver Particles ◽  
Temperature Dependent ◽  
Surface Plasmon Resonances ◽  
Localized Surface Plasmon Resonances ◽  
Plasmon Resonances ◽  
Diamagnetic State

This article describes the optical properties of nanostructures composed of silver particles embedded into a gold matrix. In previous studies these materials were shown to exhibit temperature dependent transitions to a highly conductive and strongly diamagnetic state. Here we describe the anomalous optical properties of these nanostructures. Most notably, these materials fail to obey Mie theory and exhibit an unconventional resonance with a maximum at about 4 eV, while the usual gold and silver localized surface plasmon resonances are suppressed. This effect implies a significant deviation from the bulk dielectric functions of gold and silver. We further resolved this resonance into its absorbance and scattering sub-parts. It is observed that the resonance is largely comprised of scattering, with negligible losses even at ultraviolet frequencies.

Deliquescence in the Hydrolysis of Sodium Borohydride by Water Vapor

2010 ◽  
Vol 49 (20) ◽  
pp. 9596-9599 ◽  
Author(s):  
Amy M. Beaird ◽  
Thomas A. Davis ◽  
Michael A. Matthews
Keyword(s):  
Water Vapor ◽  
Sodium Borohydride ◽  
Hydrolysis Of
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