Ovadia Lev

Followers

Following

Co-authors

Public Views

Mingyu Yu

University of California, San Diego

Stefan Adams

National University of Singapore

Hồ Văn Chương

Binson Babu

Indian Institute of Science Education and Resarch(IISER), Vithura, Trivandrum, Kerala

Karlsruhe Institute of Technology (KIT)

Bostjan Genorio

University of Ljubljana

Interests

Uploads

Papers by Ovadia Lev

An Investigation on the Relationship between the Stability of Lithium Anode and Lithium Nitrate in Electrolyte

Journal of The Electrochemical Society, 2019

An investigation on the relationship between the stability of lithium anode and lithium nitrate i... more

Download

Improved H2s Sensitivity of Nanosized Basno3 Obtained by Hydrogen Peroxide Assisted Sol-Gel Processing

Social Science Research Network, 2022

ゾル‐ゲル誘導プルシアンブルー‐けい酸電流測定グルコースセンサ

Композиционные материалы на основе оксидов и сульфидов непереходных элементов и восстановленного оксида графена - аноды для Li- и Na-ионных аккумуляторов

Back Cover: Peroxide Coordination of Tellurium in Aqueous Solutions (Chem. Eur. J. 9/2016)

Chemistry: A European Journal, Jan 12, 2016

Tellurium-peroxo complexes in aqueous solutions have never been reported. In this work, ammonium ... more Tellurium-peroxo complexes in aqueous solutions have never been reported. In this work, ammonium peroxotellurates (NH4 )4 Te2 (μ-OO)2 (μ-O)O4 (OH)2 (1) and (NH4 )5 Te2 (μ-OO)2 (μ-O)O5 (OH)⋅1.28 H2 O⋅0.72 H2 O2 (2) were isolated from 5 % hydrogen peroxide aqueous solutions of ammonium tellurate and characterized by single-crystal and powder X-ray diffraction analysis, by Raman spectroscopy and thermal analysis. The crystal structure of 1 comprises ammonium cations and a symmetric binuclear peroxotellurate anion [Te2 (μ-OO)2 (μ-O)O4 (OH)2 ](4-) . The structure of 2 consists of an unsymmetrical [Te2 (μ-OO)2 (μ-O)O5 (OH)](5-) anion, ammonium cations, hydrogen peroxide, and water. Peroxotellurate anions in both 1 and 2 contain a binuclear Te2 (μ-OO)2 (μ-O) fragment with one μ-oxo- and two μ-peroxo bridging groups. (125) Te NMR spectroscopic analysis shows that the peroxo bridged bitellurate anions are the dominant species in solution, with 3-40 %wt H2 O2 and for pH values above 9. DFT calculations of the peroxotellurate anion confirm its higher thermodynamic stability compared with those of the oxotellurate analogues. This is the first direct evidence for tellurium-peroxide coordination in any aqueous system and the first report of inorganic tellurium-peroxo complexes. General features common to all reported p-block element peroxides could be discerned by the characterization of aqueous and crystalline peroxotellurates.

Crystalline Ammonium Peroxogermanate as a Waste-Free, Fully Recyclable Versatile Precursor for Germanium Compounds

Inorganic Chemistry, Jan 16, 2019

Download

Unusual Stabilization of Zinc Peroxide by Manganese Oxide: Mechanistic Understanding by Temperature-Dependent EPR Studies

Journal of Physical Chemistry C, Jul 18, 2019

Nanocrystalline zinc peroxide is passivated against further oxidation by the addition of minute, ... more Nanocrystalline zinc peroxide is passivated against further oxidation by the addition of minute, substoichiometric amounts of potassium permanganate, which also endows it with increased thermal stability. The oxidation state of manganese and the passivation mechanism are deciphered by a comparative electron paramagnetic resonance (EPR) study of the manganese-doped zinc peroxide nanoparticles and manganese oxide formed by reduction of permanganate by hydrogen peroxide as well as unmodified ZnO 2 nanoparticles. Temperature-dependent in situ EPR studies at elevated temperatures allowed us to trace simultaneously the temperature-dependent changes in abundance of superoxide radicals and the formation of Mn(IV) species and also to identify Mn(III) species at cryotemperatures. We conclude that the passivation is caused by Mn(III) complexes that act as antioxidants removing superoxide radicals, which are abundant in zinc peroxide and even more so in the manganese-doped zinc peroxide.

Download

Effect of aluminum vacancies on the H 2 O 2 or H 2 O interaction with a gamma‐AlOOH surface. A solid‐state DFT study

International Journal of Quantum Chemistry, Feb 20, 2019

The adsorption of a single H2O2 or H2O molecule on a family of periodic slab models of γ‐AlOOH is... more The adsorption of a single H2O2 or H2O molecule on a family of periodic slab models of γ‐AlOOH is studied by solid‐state DFT. The single H2O2 or Н2О molecule interacts with the perfect (010) slab by intermolecular hydrogen bonds (H‐bonds). In the models of γ‐AlOOH with oxygen and aluminum vacancies, H2O2 or Н2О also forms covalent O∙∙∙Al bonds. The energies of covalent O∙∙∙Al and H‐bonds are estimated by a combined approach based on simultaneous consideration of the total binding energies with BSSE correction and empirical schemes of the Н‐bond energy evaluation. The O∙∙∙Al bond energy ranges from ~75 to ~156 kJ mol−1. The total energy of H‐bond interactions in the case of H2O2 exceeds that of Н2О by ~30 kJ mol−1 for all considered slab models. In contrast to Н2О, a H2O2 molecule always forms two H‐bonds as the proton donor. The energy of these bonds noticeably increase on defect γ‐AlOOH surfaces in comparison with the perfect slab due to formation of short (strong) H‐bonds by adsorbed H2O2.

Green Synthesis of a Nanocrystalline Tin Disulfide-Reduced Graphene Oxide Anode from Ammonium Peroxostannate: a Highly Stable Sodium-Ion Battery Anode

ACS Sustainable Chemistry & Engineering, Feb 28, 2020

We introduce a green synthesis approach for high performance sodium ion batteries anodes that doe... more We introduce a green synthesis approach for high performance sodium ion batteries anodes that does not involve hydrothermal treatment or excessive energy use. Wet chemistry involving ammonium peroxostannate intermediate coating of rGO can be done at low temperature without excessive use of solvents. The process is practically waste-free and does not involve acid wastes. Thermal treatment is required only for the solid material. The electrode exhibited very high stability and the charging capacity was reduced from 320 to 310 mAh g-1 after 2000 cycles at 3 A g-1. Moreover, the synthesis protocol demonstrated here is highly versatile with different, alternative pathways that provide many degrees of freedom in the process sheet design as well as in materials composition.

Download

Graphene Oxide-Supported β-Tin Telluride Composite for Sodium- and Lithium-Ion Battery Anodes

Energy technology, Nov 30, 2017

Supporting Information and the ORCIDi dentificationn umber(s) for the author(s) of this article c... more Supporting Information and the ORCIDi dentificationn umber(s) for the author(s) of this article can be foundu nder https://doi.org/10.1002/ ente.201700760. This publication is part of as pecial collection on the work of the "CREATE ResearchC ampus". To view the collection'sT able of Contents, please visit http://bit.ly/CREATE-10.

Download

Understanding Fundamentals and Reaction Mechanisms of Electrode Materials for Na-Ion Batteries

Small, Jan 22, 2018

Li and Na fall under Group I alkali metal in the periodic table and are assumed to have similar c... more Li and Na fall under Group I alkali metal in the periodic table and are assumed to have similar chemical properties. However, the performance of most electrode materials in both systems disregards a linear behavior, and they usually show reduced performance in the Na cells. [6] Nevertheless, the knowledge of the successful development of Li-ion batteries (LIBs) is beneficial for the development of NIBs as there is a large degree of similarity for the redox mechanisms in certain materials. The use of Na + as the charge carrier has several drawbacks compared with Li +. [7,8] These include: (1) Na has a larger molar mass (22.990 g mol −1) than Li (6.941 g mol −1). This makes the electrode materials containing Na heavier than their Li counterparts. (2) Na + /Na has a relatively higher reduction potential (−2.7 V vs SHE) compared with Li + /Li (E = −3.04 V vs SHE). This limits the potential of NIB anode to be higher than −2.7 V versus SHE to avoid the Na plating and the growth of Na dendrites. Thus, it is more difficult to develop NIBs with a voltage comparable or higher than LIBs. Nevertheless, −2.7 V versus SHE is still one of the lowest reduction potentials and thus NIBs yet can have a high voltage when coupled with a high-potential cathode. And (3) Na + has a larger radius (0.97 Å) than that of Li + (0.64). This may lead to a larger volume strain during sodiation and result in poor cycling performance. The larger radius of Na + may also cause its slow diffusion kinetics Development of efficient, affordable, and sustainable energy storage technologies has become an area of interest due to the worsening environmental issues and rising technological dependence on Li-ion batteries. Na-ion batteries (NIBs) have been receiving intensive research efforts during the last few years. Owing to their potentially low cost and relatively high energy density, NIBs are promising energy storage devices, especially for stationary applications. A fundamental understanding of electrode properties during electrochemical reactions is important for the development of low cost, high-energy density, and long shelf life NIBs. This Review aims to summarize and discuss reaction mechanisms of the major types of NIB electrode materials reported. By appreciating how the material works and the fundamental flaws it possesses, it is hoped that this Review will assist readers in coming up with innovative solutions for designing better materials for NIBs. Na-Ion Batteries The ORCID identification number(s) for the author(s) of this article can be found under

Download

Пероксотеллураты аммония: синтез, строение, свойства и применение для получения композиционных наноматериалов

Sensitive Analysis of Nitroguanidine in Aqueous and Soil Matrices by LC-MS

Analytical Chemistry, Aug 3, 2017

Nitroguanidine, a widely used nitramine explosive, is an environmental contaminant that is refrac... more Nitroguanidine, a widely used nitramine explosive, is an environmental contaminant that is refractory, persistent, highly mobile in soils and aquifers, and yet underresearched. Nitroguanidine determination in water and soil poses an analytical challenge due its high hydrophilicity, low volatility, charge neutrality over a wide pH range, and low proton affinity which results in low electrospray interface (ESI)-MS sensitivity. A sensitive method for the determination of nitroguanidine in aqueous and soil matrices was developed. The method is based on reduction by zinc in acidic solution, hydrophobization by derivatization, preconcentration on C18 cartridge, and LC-MS quantification. The demonstrated limit of detection (LOD) reaches 5 ng/L and 22 ng/g in water and soil, respectively. Analysis of a contaminated site demonstrates that it is possible to map a contamination plume that extends over 1 km from the source of the contamination.

Download

DOM as an indicator of occurrence and risks of antibiotics in a city-river-reservoir system with multiple pollution sources

Science of The Total Environment, Oct 1, 2019

Multiple sources contribute to the presence of antibiotic residues in water environments, and the... more Multiple sources contribute to the presence of antibiotic residues in water environments, and the environmental risks caused by antibiotics were paid more and more attention. This work aims to establish a relationship between optical properties of dissolved organic matter (DOM) and sources and risks of antibiotics. Occurrence of antibiotics and DOM in a city-river-reservoir freshwater system containing distinct antibiotic sources was investigated during three seasons using LC-MS and fluorescence excitation-emission matrix coupled with parallel factor analysis (EEM-PARAFAC), respectively. The results showed that antibiotics and DOM in the water had trends of increasing levels from the upstream to the midstream in the system. Five classes of antibiotics had statistically significant correlations with the humic-like component (C3) in the water (Pearson, p < 0.05). Especially, norfloxacin (NFX), which was dominant in the aquaculture source, significantly increased the fluorescence of C3 according to the fluorescence titration (R2 = 0.86, p < 0.01). Furthermore, fluorescence signature in the aquaculture pond posed broad humic acid-like peaks with relatively higher abundances compared to other areas. These results suggested that C3 could be recognized as an indicator of NFX from aquaculture sources. Meanwhile, C3 can largely account for ecological risks of tetracyclines according to the results of redundancy analysis. This work highlights the roles of EEM-PARAFAC on tracing the source of antibiotics and the correlations between environmental risks of antibiotics and DOM in the aquatic environment.

GeO2 Thin Film Deposition on Graphene Oxide by the Hydrogen Peroxide Route: Evaluation for Lithium-Ion Battery Anode

ACS Applied Materials & Interfaces, Mar 6, 2017

A peroxogermanate thin film was deposited in high yield at room temperature on graphene oxide (GO... more A peroxogermanate thin film was deposited in high yield at room temperature on graphene oxide (GO) from peroxogermanate sols. The deposition of the peroxo-precursor onto GO and the transformations to amorphous GeO2, crystalline tetragonal GeO2, and then to cubic elemental germanium were followed by electron microscopy, XRD, and XPS. All of these transformations are influenced by the GO support. The initial deposition is explained in view of the sol composition and the presence of GO, and the different thermal transformations are explained by reactions with the graphene support acting as a reducing agent. As a test case, the evaluation of the different materials as lithium ion battery anodes was carried out revealing that the best performance is obtained by amorphous germanium oxide@GO with &amp;amp;gt;1000 mAh g(-1) at 250 mA g(-1) (between 0 and 2.5 V vs Li/Li(+) cathode), despite the fact that the material contained only 51 wt % germanium. This is the first demonstration of the peroxide route to produce peroxogermanate thin films and thereby supported germanium and germanium oxide coatings. The advantages of the process over alternative methodologies are discussed.

Sol-Gel Electrochemistry

Electroanalytical chemistry, a series of advances, Mar 25, 2010

Brush like polyaniline on vanadium oxide decorated reduced graphene oxide: Efficient electrode materials for supercapacitor

Journal of energy storage, Apr 1, 2019

Vanadium oxides (V 3 O 7) have been used as electrode materials for supercapacitor applications b... more Vanadium oxides (V 3 O 7) have been used as electrode materials for supercapacitor applications because of its multiple oxidation states. V 3 O 7 nanoparticles were coated on reduced graphene oxide (rGO) from a peroxovanadate-rGO composite by thermal microexplosive decomposition method. These V 3 O 7 decorated rGO were made composite with the flexible multi redox conducting polymer (Polyaniline). The performance of the composite materials as electrode for supercapacitors was analyzed in a 3-electrode cell, obtaining a specific capacitance of about 579 F g −1 at 0.2 A g −1 specific current. Cycling stability is one of the main barriers noticed in V 3 O 7 , which limits the practical performance of supercapacitors. This is overcome by modifying V 3 O 7 with rGO and polyaniline composites which produces good electrical contact resulting in higher capacitances and enhanced cycling stability when compared to pristine V 3 O 7. A superior electrochemical performance and ultra-long cyclic stability of 94% over 2500 cycles was obtained through these developed electrodes.

Download

Nonlinear Dynamics in Chemical Reaction Engineering: In Celebration of Moshe Sheintuch's 70th Birthday

Israel Journal of Chemistry, May 17, 2018

Download

Water Quality of Swimming Pools in Jerusalem

Water Science and Technology, Apr 1, 1993

The Israel Ministry of Health is now revising its regulations for the assurance of safe water qua... more The Israel Ministry of Health is now revising its regulations for the assurance of safe water quality in public swimming pools. Since it is not possible to monitor each of the pathogenic microorganisms, it is often recommended to monitor indicator bacteria which provide indirect information on the water quality in the swimming pool. Three indicator microorganisms are often recommended: coliform counts (total coliforms, fecal coliforms or E. Coli), staphylococcus aureus and pseudomonas aeruginosa. A four year survey of the water quality of swimming pools in the Jerusalem District was conducted in order to determine whether the monitoring of all three indicators is necessary to assure safe water quality or is it sufficient to monitor only a single microorganism. A statistical analysis, conducted by using several different statistical techniques, reveals that the populations of the three indicator organisms are significantly interdependent but the correlations between each pair of these indicators are not sufficient to base a prediction of any of the organisms based on the measurements of the others. Therefore, it is concluded that monitoring of all three indicators should be recommended in order to provide an adequate picture of the water quality in swimming pools.

Synthesis, crystal structure and characterization of alkali metal hydroxoantimonates

Inorganica Chimica Acta, Nov 1, 2011

Several alkali metal hydroxoantimonates, K2[Sb(O)(OH)5], Na[Sb(OH)6], Cs[Sb(OH)6] and Cs2[Sb2(μ-O... more Several alkali metal hydroxoantimonates, K2[Sb(O)(OH)5], Na[Sb(OH)6], Cs[Sb(OH)6] and Cs2[Sb2(μ-O)2(OH)8] were isolated from aqueous solutions and characterized by single crystal and powder X-ray diffraction studies and by FTIR and thermal analysis. Crystal structures involving [Sb(O)(OH)5]2− were never anticipated before, and this is also the first disclosure of a dinuclear antimonate [Sb2(μ-O)2(OH)8]2−. Aqueous antimonate solutions of different pH were studied by high

An Investigation on the Relationship between the Stability of Lithium Anode and Lithium Nitrate in Electrolyte

Journal of The Electrochemical Society, 2019

An investigation on the relationship between the stability of lithium anode and lithium nitrate i... more

Download

Improved H2s Sensitivity of Nanosized Basno3 Obtained by Hydrogen Peroxide Assisted Sol-Gel Processing

Social Science Research Network, 2022

ゾル‐ゲル誘導プルシアンブルー‐けい酸電流測定グルコースセンサ