Nickel Dioxide Research Articles

Microwave induced catalytic degradation of crystal violet in nano-nickel dioxide suspensions

Nickel oxide catalyst was obtained by precipitation-oxidation method with the assistance of microwave irradiation. The samples were characterized by X-ray diffraction, Raman spectrophotometer, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, surface area and porosity analyzer. On the basis of the results, the as-prepared product was nano-NiO(2) with OH group and active oxygen. The catalytic activity of the as-prepared product might be attributed to its microwave absorbing property and the role of active oxygen, OH group under microwave irradiation. The microwave induced catalytic degradation process (MICD) with as-prepared product was further applied to degrade triphenylmethane dye crystal violet (CV). 97% of a 100 mg L(-1) sample of CV was rapidly degraded in 5 min with the corresponding 81% TOC removal. The main intermediates were separated and identified by LC-ESI-MS and GC-MS techniques. The LC-ESI-MS analytical results demonstrated that a series of N-de-methylation products were obtained in a stepwise manner, namely mono-, di-, tri-, tetra-, penta-, and hexa-de-methylated CV species. Nine organic acids with benzene ring and four low molecular acids were yielded with the assistance of GC-MS. The proposed degradation pathways were discussed in this study. The degradation processes might include N-de-methylation, destruction of conjugated structure and opening-benzene ring. MICD, as a potential technique with wide application perspective, can be used to purify triphenylmethane dye wastewater with nanosized nickel dioxide.

ChemInform Abstract: Asymmetric Intramolecular Oxa‐Michael Addition of Activated α,β‐Unsaturated Ketones Catalyzed by a Chiral N,N′‐Dioxide Nickel(II) Complex: Highly Enantioselective Synthesis of Flavanones.

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Asymmetric Intramolecular Oxa‐Michael Addition of Activated α,β‐Unsaturated Ketones Catalyzed by a Chiral N,N′‐Dioxide Nickel(II) Complex: Highly Enantioselective Synthesis of Flavanones

Asymmetric Intramolecular Oxa‐Michael Addition of Activated α,β‐Unsaturated Ketones Catalyzed by a Chiral <i>N</i>,<i>N</i>′‐Dioxide Nickel(II) Complex: Highly Enantioselective Synthesis of Flavanones

Asymmetric Intramolecular Oxa‐Michael Addition of Activated α,β‐Unsaturated Ketones Catalyzed by a Chiral N,N′‐Dioxide Nickel(II) Complex: Highly Enantioselective Synthesis of Flavanones

Der Titelreaktion ist weder luft- noch feuchtigkeitsempfindlich und bietet einen wirkungsvollen Ansatz zur Synthese von chiralen Flavanonen (siehe Schema). Eine Vielzahl von Substraten konnte mit guten bis ausgezeichneten Enantioselektivitäten unter milden Bedingungen umgesetzt werden.

High-level ab initio calculations on the NiO 2 system

Several high-level ab initio methods were employed in studies of the narrow singlet-triplet separation of the cyclic form of nickel dioxide (NiO 2). It is shown that the complete versions of the locally renormalized coupled cluster method with singles, doubles, and noniterative triples (LR-CCSD(T)) approach, in contrast to the standard CCSD(T) method, provides results in concert with predictions of the density functional theory (DFT) and internally contracted multi-reference configuration interaction method (IC-MRCI), which favor the triplet state to be the lowest one. Relevant discussion of several aspects related to the underlying CCSD calculations, indicate that the dominant role of singly excited amplitudes violates the paradigm about the leading role of two-body effects in the description of the correlation energy. We also show that the multireference perturbation theory, exemplified here by the Generalized Van Vleck Perturbation Theory, requires the use of very large model space in order to properly describe the non-dynamical correlation effects.

Synthesis and electrode performance of layered nickel dioxide containing alkaline ions

Several polymorphs of layered nickel dioxide were prepared by using the chemical insertion of alkaline ions into Li 0.10NiO 2. We used aqueous AOH (A = Li, Na, K) solutions as reducing agents. Sodium and potassium insertion resulted in hydrated layered compounds that can be classified as γ-NiOOH with high crystallinity, while lithium insertion occurred without hydration. We discuss the coordination environment around the A + ions for these inserted compounds. The thermal behavior, analyzed using high temperature (HT) X-ray diffraction (XRD) and thermogravimetric (TG) measurements, indicated that heating the hydrate at 150 °C yielded its dehydrate. The electrode performance of the nickelate was studied in lithium cells. We discuss the effect of interlayer water on cell rechargeability and the similarity between these nickelate and hydrated manganese dioxide (birnessite).

Nickel dioxide polymorphs as lithium insertion electrodes

Five kinds of nickel dioxide polymorphs, Li x NiO 2 with x≈0, were prepared by treating LiNiO 2 with sulfuric acid solutions, occasionally followed by low-temperature heating. Here we report their structure and properties as lithium insertion electrodes. Acid-treated Li 0.10NiO 2 with two layered phases turned into a single-layered compound at 160 °C and then to a spinel-related compound at 170 °C. Acid-treated Li 0.04NiO 2 contained a phase with a cadmium iodide structure, which was not observed with Li 0.10NiO 2. Heating this Li 0.04NiO 2 yielded a spinel-related compound on heating. The NiO distances in these compounds suggested that the nickel oxidation state was kept approximately +4. These ‘nickel dioxide’ polymorphs exhibited varied characteristics as lithium insertion electrodes. We discuss the electrode behavior together with the structural changes that occur during lithium insertion. We also examined the effect of the electrode drying condition on the cycling performance.

Structural and Thermal Characteristics of Nickel Dioxide Derived from LiNiO2

We report the structural and thermal characteristics of highly delithiated (lithium extracted) compounds LixNiO2, which can be called “nickel dioxide.” We obtained Li0.10NiO2 and Li0.04NiO2 by treating LiNiO2 with sulfuric acid. Both products contained phases with NiO2 stacking similar to cadmium chloride (O3-type), but the latter also included a phase with NiO2 stacking similar to cadmium iodide (O1-type). We examined their thermal behavior using high temperature X-ray diffraction analysis together with thermogravimetric analysis and found that novel polymorphs, with similar chemical compositions but different structures, were obtained by heating them at appropriate temperatures. We discuss these results together with those for LixNiO2 obtained by electrochemical delithiation. We also report acid-treated products derived from Li0.93Ni1.07O2.

Single Crystal Growth and Structural Chemistry of Li1−zNi1+zO2 with z=0.075

Single crystals of the lithium nickel dioxide compound Li1−zNi1+zO2 with z=0.075 have been successfully synthesized by a flux method for the first time. A single-crystal X-ray diffraction study confirmed trigonal symmetry, R3m space group, and the lattice parameters a=2.8899(13) Å and c=14.1938(17) Å. The cation distribution in Li0.925Ni1.075O2 was determined to be (Li0.744Ni0.256)3a[Li0.181Ni0.819]3bO2 with a final R value of 2.68% using 202 independent observed reflections. The relationships between cation distributions and structural parameters for Li1−zNi1+zO2 compounds have been summarized and discussed using the 37 reported structural data. The magnetization measurements of the present single crystal samples confirmed the history dependence of temperature versus M/H maximum at about 60 K.

Production and Structure of Electrocoatings Ni-P-TiO2-Al

Composite Ni-P-TiO2 and Ni-P-TiO2-Al layers were prepared by simultaneous electrodeposition of nickel and titanium dioxide (anatase) with an addition of Al. powder on a copper substrate from a solution in which TiO2 and Al powder were suspensed by stirring. The electrodeposition was carried out under galvanostatic conditions at a current density j = 300 mA cm−2 and temperature of 298 K. The phase composition of the layers was investigated by the X-ray diffraction method. It was found that during the electrodeposition process a spherical crystalline particle of TiO2 could be incorporated into the Ni-P phase matrix. The diffractogram of Ni-P-TiO2-Al layer shows that the layer contains crystallites of aluminium and TiO2. It means that transport of the metallic phase to the electrode is only possible when using TiO2 as its carrier. This allows to extract of aluminium in alkaline environment from the Ni-P-TiO2-Al layer and to obtain the active surface.

Electrochemical characterization of a lithiated mixed nickel-cobalt oxide (LiNi0.5Co0.5O2) prepared by sol-gel process

Lithiated transition metal oxides having a layered structure and general formula LiMO2, have been extensively studied as positive electrode active materials for lithium or lithium-ion batteries. In particular, lithium nickel dioxide (LiNiO2) and lithium cobalt dioxide (LiCoO2) present a layered structure with high diffusion coefficients for the lithium ion. This latter property is very important in order to realize practical devices having high discharge rates. LiNiO2, compared with LiCoO2, has the advantage to be a cheaper material with a higher specific capacity for lithium cycling, but its stability upon cycling can be greatly influenced by the displacement of Ni ions from the Ni layers to the Li planes as the content in lithium is reduced over a certain value. Recently, solid solutions such as LiNixCo1−xO2 have been proposed to offer a compromise between stability, cost and capacity. In this work we have studied LiNi0.5Co0.5O2 prepared by the Complex Sol-Gel Process (CSGP). The advantage of this procedure toward the solid-state process is the high homogeneity in composition and in particle dimension of the synthesized compounds. The samples have been characterized electrochemically using chronopotentiometric, voltammetric and impedance measurements in liquid electrolyte. The results indicates that CSGP-synthesized LiNi0.5Co0.5O2 shows good cyclability (after 1000 cycles about 2/3 of the initial capacity can still be cycled) only if the anodic potential is limited to about 4.2 V. The quite low values of the specific capacity (∼70 mAh/g at C/1 charge-discharge rate) can be justified by the non-complete calcination reaction, as suggested by X-ray measurements. Kinetic properties have been evaluated by Electrochemical Impedance Spectroscopy measurements, which have shown quite high values for the lithium chemical diffusion coefficient (10−7÷10−8 cm2s−1) and its unexpected decrease as deintercalation proceeds from x=0.5 in LiNi0.5Co0.5O2.

A study of nickel monoxide (NiO), nickel dioxide (ONiO), and Ni(O2) complex by anion photoelectron spectroscopy

We report the first anion photoelectron spectroscopic study of nickel monoxide (NiO), nickel dioxide (ONiO), and nickel-O2 complex, Ni(O2). The adiabatic electron affinity (EA) of NiO is measured to be 1.46 (2) eV. Five low-lying electronic excited states (A 3Π, a 1Δ, B 3Φ, b 1Σ+, c 1Π) are observed for NiO at 0.43 (4), 0.94 (4), 1.24 (3), 1.80 (10), and 2.38 (10) eV above the ground state, respectively. Two isomers are observed for NiO2, i.e., the linear ONiO dioxide and the Ni(O2) complex. The dioxide has a high EA of 3.05 (1) eV while the Ni(O2) complex has a rather low EA of 0.82 (3) eV. Two low-lying excited states are observed for ONiO at 0.40 (2) and 0.77 (3) eV above the ground state, respectively. The vibrational frequency of the ν1 mode of the ground state ONiO (X 3Σg−) is measured to be 750 (30) cm−1. The excited states of the Ni(O2) complex give broad photodetachment features starting at about 1.1 eV above the ground state. Information about the electronic structures of the nickel oxide species and chemical bonding between Ni and O and O2 is obtained and discussed.

A First Example of a “Wittig Reaction” on a Coordinated Carbon Dioxide Nickel Complex

A First Example of a “Wittig Reaction” on a Coordinated Carbon Dioxide Nickel Complex

Electrochemistry and Structural Chemistry of LiNiO2 (R3m) for 4 Volt Secondary Lithium Cells

The synthesis and characterization of for a 4 V secondary lithium cell was done. The was prepared by ten different methods and characterized by x‐ray diffraction and electrochemical methods. prepared from and [or ] exhibited more than 150 mAh · g−1 of rechargeable capacity in the voltage range between 2.5 and 4.2 V in 1M propylene carbonate solution. The reaction mechanism was also examined and explained in terms of topotactic reaction. Lithium nickelate(III) (R3m; , in hexagonal setting) was oxidized to nickel dioxide (R3m; , ) via having a monoclinic lattice (C2/m). The nickel dioxide could be reversibly reduced to lithium nickelate(III). Factors affecting the electrochemical reactivity of are given and the possibility of using for 4 V secondary lithium cells is described.

Determination of the structure and bond energies of nickel dioxide and copper dioxide

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDetermination of the structure and bond energies of nickel dioxide and copper dioxideCharles W. Bauschlicher Jr., Stephen R. Langhoff, Harry Partridge, and Mariona SodupeCite this: J. Phys. Chem. 1993, 97, 4, 856–859Publication Date (Print):January 1, 1993Publication History Published online1 May 2002Published inissue 1 January 1993https://doi.org/10.1021/j100106a010RIGHTS & PERMISSIONSArticle Views270Altmetric-Citations49LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (536 KB) Get e-Alerts

ChemInform Abstract: Sulfur Dioxide as Ligand and Synton. Part 7. Phosphane Sulfur Dioxide Nickel(0) and Palladium(0) Complexes.

AbstractThe reactions of Ni(cod)2 or in some cases of Ni(PPh3)2(CH2=CH2) with tert. phosphanes and SO2 result in formation of phosphane sulfur dioxide complexes of the type (I), (II), and (III) depending on the phosphane substituents and the reaction conditions (molar ratio, temp., solvent, SO2 concentration).

ChemInform Abstract: REDUCED FORMS OF LANTHANUM NICKEL TRIOXIDE PEROVSKITE. PART 2. X‐RAY STRUCTURE OF LANTHANUM NICKEL DIOXIDE AND EXTENDED X‐RAY ABSORPTION FINE STRUCTURE STUDY: LOCAL ENVIRONMENT OF MONOVALENT NICKEL

Chemischer InformationsdienstVolume 14, Issue 49 Physical Inorganic Chemistry ChemInform Abstract: REDUCED FORMS OF LANTHANUM NICKEL TRIOXIDE PEROVSKITE. PART 2. X-RAY STRUCTURE OF LANTHANUM NICKEL DIOXIDE AND EXTENDED X-RAY ABSORPTION FINE STRUCTURE STUDY: LOCAL ENVIRONMENT OF MONOVALENT NICKEL P. LEVITZ, P. LEVITZSearch for more papers by this authorM. CRESPIN, M. CRESPINSearch for more papers by this authorL. GATINEAU, L. GATINEAUSearch for more papers by this author P. LEVITZ, P. LEVITZSearch for more papers by this authorM. CRESPIN, M. CRESPINSearch for more papers by this authorL. GATINEAU, L. GATINEAUSearch for more papers by this author First published: December 6, 1983 https://doi.org/10.1002/chin.198349005Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume14, Issue49December 6, 1983 RelatedInformation

Mechanism and Kinetics of Reactions in the System Ni‐Ti‐O

Reactions at T=600° to 1250°C between nickel oxide and titanium dioxide, metallic nickel and titanium dioxide, and the oxidation of Ni‐TiO2 cermet were studied. The formation of compouuds was observed by temperature‐programmed reduction in hydrogen flow. At T &gt; 600°C, NiTiO3 forms. During the initial stages of the reaction, a solid solution of TiO2 in NiO is formed. The reaction is influenced by anatase‐rutile transformation. The apparent activation energy of the formation of NiTiO3 is considerably lower during the reaction in the mixture of metallic nickel with titanium dioxide (218 kJ°mol‐1 for powder and 255 kJ.mo1‐1 for cermet oxidation) than it is for the reaction between NiO and rutile (385 kJ.mol‐1).

ChemInform Abstract: STRUCTURE AND COORDINATE BONDING NATURE OF NICKEL(0) AND COPPER(I) CARBON DIOXIDE COMPLEXES. AN AB INITIO MOLECULAR ORBITAL STUDY

Chemischer InformationsdienstVolume 13, Issue 17 Physical Organic Chemistry ChemInform Abstract: STRUCTURE AND COORDINATE BONDING NATURE OF NICKEL(0) AND COPPER(I) CARBON DIOXIDE COMPLEXES. AN AB INITIO MOLECULAR ORBITAL STUDY S. SAKAKI, S. SAKAKISearch for more papers by this authorK. KITAURA, K. KITAURASearch for more papers by this authorK. MOROKUMA, K. MOROKUMASearch for more papers by this author S. SAKAKI, S. SAKAKISearch for more papers by this authorK. KITAURA, K. KITAURASearch for more papers by this authorK. MOROKUMA, K. MOROKUMASearch for more papers by this author First published: April 27, 1982 https://doi.org/10.1002/chin.198217056AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume13, Issue17April 27, 1982 RelatedInformation

Primary deuterium isotope effects in oxidations of benzyl-.alpha.-d alcohol by transition elements and related reagents: mechanisms of electron transfer

In order to assess the structural features of the activated complex in hydrogen transfer processes, benzyl-..cap alpha..-d alcohol has been oxidized to the aldehyde over a broad range of accurately controlled temperatures with four reagents: mangansese dioxide, nickel dioxide, cerium(IV), and 2, 3-dichloro-5, 6-dicyanobenzoquinone (DDQ). Estimation of the benzaldehyde (C/sub 6/H/sub 5/CHO/C/sub 6/H/sub 5/CDO) product ratios was carried out by means of a mass spectrometric technique developed for the high precision measurements required in applying the data as a mechanistic criterion. The principal results are the striking temperature-dependent k/sub H/k/sub D/ values measured for the MnO/sub 2/ and NiO/sub 2/ systems and the equally striking temperature-independent isotope effects measured for the Ce(IV) and DDQ systems. For MnO/sub 2/ and NiO/sub 2/, the activation parameters are of magnitudes which indicate tunneling in a reaction of linear hydrogen transfer. Conclusions drawn from comparison of Cr(VI), Mn(IV) and Ni(IV) oxidations of normal alcohols is that the coupled electron and hydrogen-transfer events in oxidation by transition elements tend to occur within the planar structure of a 5-membered cyclic arrangement of reaction centers. The temperature-independent results of the Ce(IV) and DDQ oxidations are interpreted in terms of an activated complex of cyclic structure, but withmore » a nonlinear H-transfer geometry.« less