Ni Acetate Research Articles

In situ synthesis of FeNi3/(Fe,Ni)9S8/Ni4S3/C nanorods and enhancement of oxygen evolution reaction properties

NiFe-based nanomaterials have emerged as highly promising catalysts to replace platinum, ruthenium and iridium for oxygen evolution reaction (OER), in “green hydrogen” production process through water splitting. Using iron (2+) sulfate and nickel acetate as the raw materials, with the molar ratio of Ni acetate to iron (2+) sulfate controlled at 8:5, the concentration of metal-ion was 0.6 mol/L, and precursor fibers rich in Ni2+, Fe2+, and SO4 2− were prepared using electrospinning technology, with polyvinyl alcohol acting as the colloid. Subsequently, composite nanorods rich in the elements of Ni, Fe, S, and C were successfully obtained at a heat treatment temperature of 1000°C in an Ar gas atmosphere. The results demonstrate that the nanorod samples possessed a surface diameter of ~200 nm, and the main phases of the nanorods after heat treatment at 1000°C included FeNi3 alloy, (Fe,Ni)9S8, Ni4S3, and amorphous C. Electrochemical performance tests conducted in a 1.0 mol/L KOH solution exhibited excellent oxygen evolution reaction properties of the catalysts prepared using FeNi3/(Fe,Ni)9S8/Ni4S3/C nanorods as the materials. The overpotential was about 258.6 mV of the catalyst material at 10 mAcm−2.

Novel promising aqueous electrolytes for manganese dioxide/stainless steel pseudocapacitor electrode

Manganese dioxide (MnO2) films are developed by potentiostatic electrodeposition on a stainless steel sheet as a current collector using manganese acetate tetrahydrate solution at a concentration of 0.25 mol L−1. The deposited sample layer is found to be amorphous as confirmed by the scanning electron microscope (SEM) and X-ray diffraction (XRD) analyses. The capacitive property of the prepared electrodes is characterized by charging/discharging, cyclic voltammetry, and electrochemical impedance spectroscopy techniques in four different aqueous solutions; sodium sulfate, magnesium acetate, nickel acetate, and a mixture of sodium chloride + sodium bicarbonate + borax. Charge–discharge curves reveal higher specific capacitance (Cs) of 1580 F g−1 at 0.5 mA cm−2 for the investigated MnO2 film which is characterized in Ni acetate aqueous solution. The structural, morphological, and electrochemical properties of the electrodeposited manganese oxide films are also studied. The results indicate that the specific capacitance of the deposited samples showed a strong dependency on the electrolyte aqueous solutions, resulting in developing new electrolytes which is a top priority effort in comparison to seeking new electrode materials. It is found that the matching between the pore size structure of the electrode and the ion size of the electrolyte is of great importance for the improved capacity of prepared capacitors.

Ni(II) complexes with in-situ generated N, O-bidentate aroylhydrazone Schiff base ligands: One-pot synthesis, characterization, crystal structure, and in-silico studies

A series of novel aroylhydrazone-based Ni(II) complexes were synthesized by using analogous Schiff base ligands prepared in-situ by reacting 4-[(4-methylbenzyl)oxy]benzoylhydrazine with different aldehydes in the presence of Ni(II) acetate tetrahydrate. The correspondent [NiL2] complexes, 4-7, were characterized by physicochemical techniques, viz., molar conductance, magnetic susceptibility measurement, IR, NMR, and mass spectroscopic techniques. The single-crystal X-ray structural analyses of complexes 4, 6 and 7 showed a distorted square-planar geometry for Ni atoms with deprotonated ligands in trans-configuration bound via azomethine-N and carbonylate-O atoms. Next, quantum chemical methods were incorporated to investigate their thermochemical, molecular orbital, and electrostatic potential properties. Computer-aided drug design methods were also implemented to assess their medicinal, pharmacological, and toxicological properties. Molecular docking and interaction analyses disclosed their potential binding affinity against human lung Cytochrome P450 2A13 receptor protein. Pharmacokinetic and toxicological studies suggest their relatively safe drug administrative properties.

Tuning Catalytic Activity of Ni–Co Nanoparticles Synthesized by Gamma‐Radiolytic Reduction of Acetate Aqueous Solutions

AbstractTransition metal‐based catalysts show great potential to replace Pt‐based material in energy conversion devices thanks to their low cost, reasonable intrinsic activity, thermodynamic stability, and corrosion resistance. The electrochemical performance of such catalysts is sensitive to their composition and structure. Here, it is demonstrated that homogeneous alloy nanoparticles with varying Ni‐to‐Co ratio and controlled structure can be synthesized from aqueous Ni(Co) acetate solutions using a facile γ‐radiolytic reduction method. The obtained samples are found to possess defects that are ordered to form polytypes structures. The concentration of these defects depends on the Ni‐to‐Co ratio, as supported by the results of ab initio calculations. It is found that structural defects may influence the activity of catalysts toward the oxygen evolution reaction, while this effect is less pronounced with respect to the oxygen reduction reaction. At the same time, the activity of Ni–Co catalysts in the hydrogen evolution reaction is affected by formation of NiOH bonds on the surface rather than by the presence of structural defects. This study demonstrates that the composition of NiCo nanoparticles is an essential factor affecting their structure, and both composition and structure can be tuned to optimize electrochemical performance with respect to various catalytic reactions.

Creating, Preserving, and Directing Carboxylate Radicals in Ni-Catalyzed C(sp3)–H Acyloxylation of Ethers, Ketones, and Alkanes with Diacyl Peroxides

The reaction of Ni(II) acetate with diacyl peroxides produces high-valence Ni-species capable of catalytic oxidative acyloxylation of C(sp3)–H bonds in ethers, ketones, and alkanes. The desired esters were obtained in 20–82% yields. Computational analysis suggests that activation of the peroxide moiety produces a dynamically interconverting mixture of catalytic Ni-species in the formal Ni(III) state. Remarkably, in these species, coordination of the RCO2 group at Ni preserves radical character at the carboxylate moiety (i.e., carboxylate radical acts as an “L-ligand”), so the latter can induce fast C–H abstraction. The spirocyclopropyl moiety prevents premature radical decarboxylation via a combination of hybridization factors and stereoelectronic effects. A variety of viable C–H activation patterns were identified experimentally and computationally.

Square-planar and octahedral nickel complexes of an acylhydrazone ligand and the serendipitous isolation of a potential octahedral nickel acylhydrazone precursor

An investigation of the coordination chemistry of the ((E)-N′-(4-hydroxybenzylidene)-4-hydroxybenzohydrazide) Schiff-based ligand (HL) towards Ni(ii) acetate was performed using single crystal X-ray diffraction.

Influence of Ni on the structural evolution of polymer-derived SiOC ceramics

Polymer derived ceramics (PDCs) technique is an advanced method for preparing high performance ceramics, in which pyrolysis process is an important step. In order to study the effect of the Ni transition metal on the pyrolysis process of polysiloxane, different contents of Ni acetate tetrahydrate (Ni(ac)2·4H2O)-impregnated polysiloxane (PSO) precursors were pyrolyzed in argon atmosphere between 1000 °C and 1300 °C. The organic-inorganic conversion behavior of precursors, the elemental and structural characterization of the Ni-free and Ni-containing SiOC ceramics were investigated. The results revealed that the presence of Ni not only enabled the growth of carbon nanotubes (CNTs) but also promoted the crystallization of carbon and SiC phase during the pyrolysis process. Additionally, high Ni content and pyrolysis temperature raised the diameters of CNTs and crystallinity of turbostratic layer carbon and SiC.

Supramolecular assemblies in an unprecedented asymmetric salamo-based dinuclear nickel(II) complex bearing two different coordination modes

An unprecedented dinuclear Ni(II) complex [{Ni2(L)(HL)(μ-OAc)(H2O)}2]·3CH3CH2OH is successfully synthesized by the complexation of an asymmetric salamo-based ligand (H2L) and Ni(II) acetate tetrahydrate and characterized by elemental analyses, UV-Vis and IR spectra, and X-ray crystallography analyses. Surprisingly, in the asymmetric unit of the Ni(II) complex, a fully deprotonated ligand (L)2– unit and a partially deprotonated ligand (HL)– unit wrapps two Ni(II) atoms, with the μ-OAc– anion bridging two adjacent Ni(II) atoms. The two Ni(II) atoms possess different coordination environments and twisted octahedral geometries. The hexacoordinated Ni(II) atom (Ni1) is located in the N2O4 donor cavity, but another hexacoordinated Ni(II) atom (Ni2) is located in a NO5 donor coordination environment. Meanwhile, a1D chain structure is formed by two N—O⋯π interactions. Hirshfeld surfaces and fluorescent properties are investigated.

Synthesis, crystallographic structure and hirshfeld surface analysis of nickel(II) chelate derived from O,N,S-donor tridentate thiosemicarbazone

• A tridentate ONS donor thiosemicarbazone and its nickel complex was synthesized. • The thiosemicarbazone exhibits thioamido form in the solid state whereas in complex it adopts dianionic thiolato form. • The structure of the complex exhibits distorted square planar in geometry. • Hirshfeld surface analysis and the decomposed 2D fingerprint plots provide a visual analysis of various intermolecular interactions present. • The shape index function shows the presence of π..π stacking interactions. New mononuclear complex [NiLβ-pic] has been synthesized by the reaction of Ni(II) acetate with salicylaldehyde 3-azacyclothiosemicarbazone (H 2 L) in the presence heterocyclic base, β-picoline as an auxiliary ligand. The complex has been investigated by elemental analysis, FT-IR, UV-Vis, 1 H NMR and 13 C NMR spectroscopy. These data show that the thiosemicarbazone acts as a dianionic tridentate ligand and coordinated to the metal through azomethine nitrogen, thioiminolate sulfur and phenolate oxygen. The coordination sphere is completed by β-picoline. The magnetic susceptibility measurement indicates that the complex is mononuclear and diamagnetic. The structure of the compound is also confirmed by single crystal X-ray crystallography and was found to be distorted square planar in geometry around Ni(II) metal ion centre in which the angles deviated from ideal 90° with a maximum value of 6.85° occupied by azomethine nitrogen, thiolato sulfur, phenolato oxygen and pyridyl nitrogen atoms. Hirshfeld surface analysis (d norm surfaces and two-dimensional fingerprint plots) for the compound were performed and discussed.

Removal of Acidic-Sulfur-Containing Components from Gasoline Fractions and Their Simulated Analogues Using Silica Gel Modified with Transition-Metal Carboxylates.

The removal of acidic sulfur-containing components [hydrogen sulfide (H2S) and alkanethiols or thiols (RSH)] from simulated mixtures and analogues of gasoline fractions with Zn(II), Cu(II), Co(II), and Ni(II) acetates, pivalates, and malonates applied on silica gel with various porosities under ultrasonic treatment in solution has been studied. The dependence of the adsorption of H2S and RSH on the surface of silica gel modified by metal complexes with organic ligands on various factors (the pore size of the silica gel, the time of ultrasonic treatment, and the nature of carboxylate complexes) is established. The best results for the removal of total sulfur from the model mixture and an analogue of the gasoline fraction were obtained using silica gel modified with zinc pivalate (96%) and cobalt pivalate (95%). A waste-free method to desulfurize fuel with zinc pivalate based on the production of practically useful ZnS is suggested.

Ni-N4 sites in a single-atom Ni catalyst on N-doped carbon for hydrogen production from formic acid

The purposes of this research were to synthesize single-atom 1 wt% Ni catalysts for the hydrogen production from formic acid using a simple impregnation of N-doped carbon with Ni acetate, to elucidate the nature of the Ni site using a combination of experimental methods with density functional theory calculations, to propose a reaction mechanism with this Ni site and to compare the catalytic properties of the single-atom catalysts with those of a traditional Ni catalyst with nanoparticles (3.9 nm). We found that the single Ni atom formed a Ni-N4 site in a double vacancy of curved N-doped graphene. Mass-based catalytic activities of the single-atom and traditional catalysts were close. The mechanism of the reaction involved the formation of formate through participation of the Ni and N atoms. The highest energy barrier (1.088 eV) was determined for the step of recombination of hydrogen atoms. This barrier corresponded well to the experimental apparent activation energy.

Nanofabrication of (Cr2O3)x (NiO)1-x and the impact of precursor concentrations on nanoparticles conduct

This study aims to synthesize the (Cr2O3)x (NiO)1-x nanoparticles at lower and higher precursor values using the calcination method. There is a lack in regard to investigating the lower and higher precursor values on structural and optical properties of the (Cr2O3)x (NiO)1-x nanoparticles. To synthesize the (Cr2O3)x (NiO)1-x nanoparticles, Cr (III) acetate hydrate and Ni (II) acetate tetrahydrate were reacted with poly (vinyl alcohol). Several techniques, including X-ray diffraction (XRD), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FT-IR), have been employed to characterize the synthesized sample. The XRD pattern analysis indicated that, following calcination, nanoparticle formation occurred, indicating hexagonal crystalline structures (HCP) and face-centred cubic (FCC) of (Cr2O3)x (NiO)1-x nanoparticles. FT-IR verified the existence of Ni–O and Cr–O as the original compounds of ready (Cr2O3)x (NiO)1-x nanoparticle samples. In term of average particle size, this varied from 5 to 16 nm when the precursor concentration rised from x = 0.20 to x = 0.80, as reflected in the TEM results. X-ray photoelectron spectroscopy (XPS) was employed to measure the valence state and surface composition of the prepared product nanoparticles. To identify the optical band gap using the Kubelka–Munk equation, diffuse UV–visible reflectance spectra were employed, which revealed that the energy band gap fell with a rise in the value of x. In addition, photoluminescence (PL) spectra indicated that the photoluminescence intensity was related to a directly proportional way to particle size. Hence, the results can be employed with a broad range of applications in solar cell energy applications at higher x values and antibacterial activity at lower x values.

NiMo Catalysts Supported on Al-Based Mixed Oxide Prepared By Hydrothermal Method: Effect of Zn/Al Ratio and Addition of Silica on HDS Activity

The effect of Zn/Al ratio and addition of silica to Al–Znx oxides on the structure and catalytic properties of supported NiMo catalysts in hydrodesulfurization reaction of thiophene was studied. NiMo catalysts were synthesized by simultaneous impregnation of Ni acetate and 12-molybdophosphoric acid on Al–Znx and Al–Zn0.16–Si mixed oxide (with x = Zn/Al ratio of 0.05–0.57) prepared by hydrothermal synthesis at 180 °C. Colloidal SiO2 was added to the Al–Znx oxides (Si/Al = 0.3 ratio) to modify textural and structural properties of NiMo catalysts. These materials were characterized by N2 physisorption, SEM, XRD, FTIR, UV–Vis DRS, TPR–H2, TPD–NH3, XPS, HRTEM and tested in thiophene conversion at 280–400 °C and 1.0 MPa. It was found out that the surface area of the supports calcined at 500 °C, decreases with the increasing Zn/Al ratio, which could be due to the interaction of the Zn with the alumina, leading to formation of Zn-spinel. After impregnation of the supports with NiMo active components, the presence of Zn increases the amount of surface Mo in octahedral sites at Zn/Al = 0.21 ratio. At this ratio maximum in HDS activity of NiMo/Al–Znx samples was observed. Addition of silica to Al-Zn mixed oxide (Zn/Al = 0.16) leads to more active NiMo catalyst due to formation of more Ni(Zn)–Mo–S active species as revealed by XRD and HRTEM.

The Cycle Destruction during Complex Formation of 4-salicylideneamino-3-hydrazino-5-mercapto-1,2,4-triazole with Ni (II) ions

Using single crystal X-ray diffraction method, it was shown that the interaction of 4-salicylideneamino-3-hydrazino-5-mercapto-1,2,4-triazole with Ni (II) acetate yields a complex of nickel with salicylidene-thiosemicarbazone instead of the expected complex with the corresponding Schiff base. A possible mechanism of hydrolysis of the thiotriazole ring is proposed. The N- (salicylidene) thiosemicarbazone is a tridentate and almost flat structure ligand coordinates to the nickel (II) cation through thiosemicarbazone sulphur, phenolic oxygen, and azomethine nitrogen atoms. The nickel (II) ion in the complex is four-coordinated in distorted square-planar geometry. The intermolecular hydrogen bonds N─H∙∙∙N, as well as hydrogen bonds N─H∙∙∙O, O─H∙∙∙O and O─H∙∙∙S through the solvate water molecules, give rise to the 3-D network of the complex [Ni(TSC)((NH2)2CS)]•H2O.

The Cycle Destruction during Complex Formation of 4-salicylideneamino-3-hydrazino-5-mercapto-1,2,4-triazole with Ni (II) ions

Using single crystal X-ray diffraction method, it was shown that the interaction of 4-salicylideneamino-3-hydrazino-5-mercapto-1,2,4-triazole with Ni (II) acetate yields a complex of nickel with salicylidene-thiosemicarbazone instead of the expected complex with the corresponding Schiff base. A possible mechanism of hydrolysis of the thiotriazole ring is proposed. The N- (salicylidene) thiosemicarbazone is a tridentate and almost flat structure ligand coordinates to the nickel (II) cation through thiosemicarbazone sulphur, phenolic oxygen, and azomethine nitrogen atoms. The nickel (II) ion in the complex is four-coordinated in distorted square-planar geometry. The intermolecular hydrogen bonds N─H∙∙∙N, as well as hydrogen bonds N─H∙∙∙O, O─H∙∙∙O and O─H∙∙∙S through the solvate water molecules, give rise to the 3-D network of the complex [Ni(TSC)((NH2)2CS)]•H2O.

Novel in-situ preparation of nano sized Ni (0) catalyst for depolymerization of lignin-rich waste from industrial biorefinery

Lignin-rich waste are valuable sources of chemicals and other materials but the depolymerisation processes are still unworkable on industrial scale. One of the problems ongoing is the catalyst preparation which often requires laborious and time-consuming processes.In this paper, a first example of easy preparation of in-situ Ni(0) nano sized catalyst for lignin-rich industrial waste hydrogenolysis is reported. Ni(0) particles were produced by reduction of Ni(II) acetate dissolved in alcoholic suspension of lignin. Soda lignin was isolated from the solid stream of a second generation bioethanol industrial plant and was depolymerized to low molecular weight chemicals by Ni(0) and/or Pd/C in alcoholic media. In 1,2-propandiol at 210 °C, up to 70% of starting material was converted into soluble compounds with an overall yield of monolignol derivatives of about 18%. The remaining material is constituted by lignin fragments with molecular weight between 400 and 1400 Da. The oligomers formation and distribution was discussed.

Synthesis, Characterization, and Biological Applications of New Series of Azo Triazole Organometallic Derivatives and Their Silver Nanoparticle Forms

Some metal salts can react with 3-amino-1,2,4-triazole derivatives as Ni(II) acetate, Co(II) acetate and Cu(II) acetate afforded metallated products Ia-d, IIa-d and IIIa-e in the form of monometal, dimetal, and metal bis products. Elemental analyses, IR, 1H NMR, 13C NMR and mass spectral elucidated the structures of the newly synthesized compounds. Some of the azo metal compounds were treated with silver nanoparticles. Transmission electron microscopy is used to determine the morphology and particles size via TEM image of nanoparticles and nano form of compounds. The antimicrobial activity of the recently synthesized compounds and its nano form has been measured against gram positive and gram negative bacteria and fungi.

An efficient electrocatalyst of NiO supported on carbon paper for nonaqueous Li–O2 batteries

A Li–O2 battery has been considered as one of the most promising energy storage systems owing to their ultrahigh theoretical energy densities. However, low energy efficiency (high polarization) during discharge/charge and resulting cycle stabilities have severely limited the development of this type of battery. Here, we demonstrate a simple preparation of NiO supported on carbon paper by dipping carbon paper in Ni acetate solution and heating it to apply NiO directly to the carbon as a cathode material for nonaqueous Li–O2 batteries. The prepared sample was confirmed as the structure of NiO-incorporated carbon using X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XAS), and high-resolution transmission electron microscopy (HR-TEM) analysis despite amorphous patterns seen in XRD (~ 10% NiO in NiO supported on carbon paper). A Li–O2 cell in which the NiO supported on carbon paper was applied as an electrocatalyst showing an initial ~ 6% increase in energy efficiency and a subsequent 50 cycle retention.

Efficient Electrochemical Reduction of CO2 by Ni–N Catalysts with Tunable Performance

Developing highly selective and durable catalysts for electrochemical CO2 reduction (ECR) to valuable chemicals is essential for curbing CO2 emissions into the atmosphere and to close the anthropogenic carbon cycle. Herein, we report facile and scalable synthesis of Ni/NC as an efficient low-cost catalyst for ECR to CO. The electrocatalytic properties of the catalysts can be readily tailored by tuning N configurations and the fraction of single Ni sites in Ni/NC via manipulation of the N precursor and annealing conditions. The Ni/NC catalyst designed by thermal treatment of a composite mixture of carbon black, Ni(II) acetate, and polyacrylonitrile achieved low overpotential CO2 to CO conversion with a Faradaic efficiency (FE) as high as 96.5% at −0.9 V (vs reversible hydrogen electrode, RHE), a current density reaching −12.6 mA cm–2 at −1.2 V (vs RHE) corresponding to a CO turnover frequency of up to 4760 h–1. In addition, high FEs for CO formation (≥84.7%) were obtained in a wide potential range from −0.8 to −1.2 V (vs RHE) on the Ni/NC electrode. X-ray photoelectron spectroscopy and X-ray absorption near-edge structure spectra in combination with multiple electrochemical results suggested that the pyrrolic N and Ni–N structures concertedly play a determinant role in the catalytic performance of Ni/NC during the CO2 reduction reaction.

Polysilsesquioxanes Containing Superparamagnetic Nanoclusters of Cobalt or Nickel

A method was developed for the synthesis of ion-coordinated polysilsesquioxanes (OSS-M) by reaction of amphiphilic carboxyl-containing oligosilsesquioxanes (OSS-COOH) with Co and Ni acetates. The OSS-M contain two types of crystalline phases, one of which is formed as a result of interaction of the alkyl chains while the other results from the formation of hydrogen bonds and coordination bonds. The size of the clusters formed by the metal ions, estimated from measurements of their magnetic moments, amounts to 2-3 nm. The magnetic nanoclusters formed by the Co ions in thin polymer films are anisotropic with respect to the plane of the substrate while the Ni ions are isotropic.