scholarly journals Water Decomposition Occurring During Laser Breakdown of Aqueous Solutions Containing Individual Gold, Zirconium, Molybdenum, Iron or Nickel Nanoparticles

2020 ◽  
Vol 8 ◽  
Author(s):  
Ilya V. Baimler ◽  
Andrey B. Lisitsyn ◽  
Sergey V. Gudkov
Keyword(s):  
Au Nanoparticles ◽  
Nickel Nanoparticles ◽  
Optical Breakdown ◽  
Water Molecules ◽  
Ni Nanoparticles ◽  
Water Decomposition ◽  
Colloidal Solutions ◽  
Decomposition Products ◽  
Laser Breakdown ◽  
Chemical Products

Generation rates of hydrogen peroxide (H2O2), hydroxyl radicals (•OH), molecular hydrogen (H2), and molecular oxygen (O2) forming during the optical breakdown of aqueous colloidal solutions containing Au, Mo, Zr, Fe, and Ni nanoparticles have been studied. It is shown that the processes occurring during the dissociation of water molecules under the influence of laser breakdown plasma and leading to the formation of various chemical products depend on the material of the nanoparticles present in the colloid. It was found that the highest rates of generation of water decomposition products are observed in aqueous colloidal solutions of Fe and Ni nanoparticles. The use of Au nanoparticles leads to the lowest generation rate. In general, the materials from which the nanoparticles are made, depending on the efficiency of the formation of water decomposition products, are arranged as follows: Ni> Fe> Mo> Zr> Au.

Investigation of the laser-induced breakdown plasma, acoustic vibrations and dissociation processes of water molecules caused by laser breakdown of colloidal solutions containing Ni nanoparticles

2021 ◽  
Author(s):  
Ilya Baymler ◽  
Alexander Vladimirovich Simakin ◽  
Sergey Vladimirovich Gudkov
Keyword(s):  
Irradiation Time ◽  
Average Distance ◽  
Optical Breakdown ◽  
Maximum Pressure ◽  
Ni Nanoparticles ◽  
Nanoparticle Concentration ◽  
Colloidal Solutions ◽  
Nanosecond Pulses ◽  
Laser Breakdown ◽  
Laser Induced Breakdown

Abstract In this work the process of optical breakdown under laser irradiation by nanosecond pulses with an energy of 650 mJ of aqueous solutions of Ni nanoparticles is investigated. A monotonic change in the number of breakdowns, the average distance between closest breakdowns, the average plasma size of an individual breakdown, the luminosity of a plasma flash, the intensity of acoustic signals, and the rate of formation of dissociation products - O2, H2, OH•, and H2O2 with an increase in the irradiation time was established. With an increase in the concentration of nanoparticles, the measured values change non-monotonically. The maximum luminosity of a plasma flash is observed at a nanoparticle concentration of 109 NP/ml and 1010 NP/ml and reaches 350 cd/m2. The maximum pressure at the shock front is 1.5–2 MPa at a nanoparticle concentration of 1010 NP/ml. The maximum rates of generation of O2, H2, OH• and H2O2 are observed at concentrations of 109 NP/ml and 1010 NP/ml. Correlation analysis of the studied physicochemical phenomena shows that the formation of molecular gases is associated with acoustic processes, and the formation of radical products and hydrogen peroxide correlates with the physicochemical properties of plasma.

scholarly journals Influence of Gases Dissolved in Water on the Process of Optical Breakdown of Aqueous Solutions of Cu Nanoparticles

2020 ◽  
Vol 8 ◽  
Author(s):  
Ilya V. Baimler ◽  
Andrey B. Lisitsyn ◽  
Sergey V. Gudkov
Keyword(s):  
Molecular Hydrogen ◽  
Colloidal Solution ◽  
Control Sample ◽  
Optical Breakdown ◽  
Acoustic Signals ◽  
Atmospheric Gases ◽  
Colloidal Solutions ◽  
Laser Breakdown ◽  
Integral Luminosity ◽  
Effect Of Gases

The paper investigates the effect of gases dissolved in water on the processes occurring during the laser breakdown of colloidal solutions of nanoparticles. The dynamics of the dependences of the plasma luminosity and acoustic signals on the concentration of nanoparticles under irradiation of colloids of nanoparticles saturated with air, argon, and molecular hydrogen has been studied. It is shown that irradiation of colloids saturated with molecular hydrogen and argon leads to an increase in the integral luminosity and integral acoustic signals in comparison with the control sample saturated with atmospheric gases, which indicates the obvious presence of the influence of gases dissolved in the liquid on the optical breakdown process. The most intense acoustic signals, as well as the brightest breakdowns, were observed when the colloidal solution was saturated with molecular hydrogen.

scholarly journals Elucidation of the higher coking resistance of small versus large nickel nanoparticles in methane dry reforming via computational modeling

2017 ◽  
Vol 7 (15) ◽  
pp. 3339-3347 ◽  
Author(s):  
Hristiyan A. Aleksandrov ◽  
Nikolaos Pegios ◽  
Regina Palkovits ◽  
Kalin Simeonov ◽  
Georgi N. Vayssilov
Keyword(s):  
Computational Modeling ◽  
Nickel Nanoparticles ◽  
Dry Reforming ◽  
Ni Nanoparticles ◽  
Methane Dry Reforming ◽  
Carbon Chains

Monoatomic C species remain separated in the subsurface regions of small Ni nanoparticles, while in larger particles, carbon chains are formed, which can be considered as precursors for coke or graphene formation.

One-step coating of commercial Ni nanoparticles with a Ni, N-co-doped carbon shell towards efficient electrocatalysts for CO2 reduction

2020 ◽  
Vol 56 (54) ◽  
pp. 7495-7498
Author(s):  
Fangxin Mao ◽  
Peng Fei Liu ◽  
Pengfei Yang ◽  
Jinlou Gu ◽  
Hua Gui Yang
Keyword(s):  
Nickel Nanoparticles ◽  
Co2 Reduction ◽  
Carbon Shell ◽  
Ni Nanoparticles ◽  
One Step ◽  
Co Doped

Commercial nickel nanoparticles (Ni NPs) were directly converted to efficient electrocatalysts for CO2 reduction by urea–Ni solid powder pyrolysis, in which a Ni, N-co-doped graphite carbon shell wraps the Ni NPs in situ.

Influence of particle size and dielectric environment on the dispersion behaviour and surface plasmon in nickel nanoparticles

2017 ◽  
Vol 19 (21) ◽  
pp. 14096-14106 ◽  
Author(s):  
Vikash Sharma ◽  
Chanderbhan Chotia ◽  
Tarachand Tarachand ◽  
Vedachalaiyer Ganesan ◽  
Gunadhor S. Okram
Keyword(s):  
Particle Size ◽  
Zeta Potential ◽  
Surface Plasmon ◽  
Nickel Nanoparticles ◽  
Ni Nanoparticles ◽  
Uv Visible ◽  
Dielectric Environment

Schematic showing the effect of the dielectric environment on the zeta potential and UV-visible absorbance of monodispersed Ni nanoparticles.

Magneto-Optics of Cobalt and Nickel Nanoparticles Implanted in SiO2: Comparative Study

2014 ◽  
Vol 215 ◽  
pp. 214-217 ◽  
Author(s):  
Dmitriy A. Petrov ◽  
Irina S. Edelman ◽  
Ruslan D. Ivantsov ◽  
Sergey M. Zharkov ◽  
Andrey L. Stepanov
Keyword(s):  
Electron Microscopy ◽  
Surface Plasmon Resonance ◽  
Nickel Nanoparticles ◽  
Magnetic Circular Dichroism ◽  
Spherical Shape ◽  
Fused Silica ◽  
Implantation Technique ◽  
Ni Nanoparticles ◽  
Thin Nickel ◽  
Cobalt And Nickel

Co and Ni nanoparticles were fabricated in fused silica plates by ion implantation technique. Electron microscopy showed the nanoparticles to be of spherical shape. Magnetic circular dichroism (MCD) was investigated in the spectral range 1.2 - 4.2 eV in a field of about 3 kOe. MCD spectra are considerably different from the spectra of thin nickel and cobalt films. MCD spectra for Ni nanoparticles are associated with surface plasmon resonance.

Factors Affecting Formation of Metastable Ni3C Phase in a Solution-Based Method

2008 ◽  
Vol 8 (9) ◽  
pp. 4477-4481 ◽  
Author(s):  
Yonghua Leng ◽  
Yang Liu ◽  
Xubo Song ◽  
Xingguo Li
Keyword(s):  
Organic Molecule ◽  
Nickel Nanoparticles ◽  
Ni Nanoparticles ◽  
Organic Solution ◽  
Reaction Conditions ◽  
Factors Affecting ◽  
Diffusion Controlled ◽  
Wide Range ◽  
Organometallic Precursors ◽  
Carbon Component

Ni3C nanoparticles are synthesized over a wide range of reaction conditions by thermal decomposition of organometallic precursors in the organic solution medium. It is found that Ni3C nanoparticles are formed using Ni nanoparticles as an intermediate. The carbon component originating from the organic solution medium to enter into Ni metal lattice is identified as a diffusion-controlled reaction, which is speeded up by increasing the reaction temperature and completed by prolonging the reaction time. Any organic molecule which contains active carbon atoms is found to be a good candidate as carbon source and combine with nickel nanoparticles to form Ni3C phase. Although this paper emphasizes on the preparation of metastable Ni3C phase, at the same time, this work could effectively direct the synthesis of Ni nanoparticles in organic solution, by avoiding the formation of Ni3C phase.

In situ reduction of well-dispersed nickel nanoparticles on hierarchical nickel silicate hollow nanofibers as a highly efficient transition metal catalyst

RSC Advances ◽  
2016 ◽  
Vol 6 (39) ◽  
pp. 32580-32585 ◽  
Author(s):  
Yang Yang ◽  
Renxi Jin ◽  
Shuo Zhao ◽  
Jihong Liu ◽  
Yunfeng Li ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Transition Metal ◽  
Nickel Nanoparticles ◽  
Metal Catalyst ◽  
Ni Nanoparticles ◽  
In Situ Reduction ◽  
Hollow Nanofibers ◽  
Transition Metal Catalyst ◽  
Nickel Silicate

Ni nanoparticles were immobilized on the hierarchically double-shell nickel silicate hollow nanofibers, the composites exhibited an excellent catalytic activity.

Synthesis and Characterization of Carbon-Encapsulated Nickel Nanoparticles from De-Oiled Asphalt

2013 ◽  
Vol 652-654 ◽  
pp. 202-205
Author(s):  
Jun Yu ◽  
Bing She Xu
Keyword(s):  
Nickel Nanoparticles ◽  
Carbon Matrix ◽  
Core Shell ◽  
Ni Nanoparticles ◽  
X Ray Diffraction ◽  
Shell Nanoparticles ◽  
Nickel Powders ◽  
Transmission Electron ◽  
Core Shell Nanoparticles

Carbon-encapsulated Ni nanoparticles with the size of 5 to 30 nm were synthesized from de-oiled asphalt (DOA) by heat-treatment at 1800 °C with nickel powder. The nanoparticles exhibited well-constructed core-shell structures, with Ni cores and graphitic shells. High resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) examinations confirmed that the carbon-encapsulated Ni nanoparticles were uniformly dispersed in carbon matrix and the Ni nanoparticles were surrounded by several carbon layers with well ordered arrangement. The formation of the core-shell nanoparticles was selectively controlled by adjusting the ratio of de-oiled asphalt to nickel powders. The possible growth model for the carbon-encapsulated Ni nanoparticles was discussed briefly. This result presents a simple and controllable way to synthesize carbon-encapsulated nickel nanoparticles.

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