Free Nickel Research Articles

Elaboration and structural characterization of phosphate glasses with composition 37.5Na2O-25[(1-x)MgO-xNiO]-37.5P2O5 (0≤x≤1)

Phosphate glasses, with molar compositions 37.5Na2O-25[(1-x)MgO-xNiO]-37.5P2O5 (0 ≤ x ≤ 1), have been prepared using the conventional melt quenching technique. The free nickel glass is colorless while the glasses containing nickel are yellow. The effect of Ni2+ ions on structural and physico-chemical properties of these glasses has been investigated by XRD, DTA, EPR, Raman, FTIR spectroscopies and by density and chemical durability measurements. Substitution of Ni2+ for Mg2+ strengthens the glass network, as shown by the decrease of the molar volume, the increase of the glass transition temperature, and the improvement of the chemical durability. This behavior is a consequence of the replacement of Mg-O bonds by more covalent Ni-O bonds. The glass structure consists of tri-phosphate (P3O10) 5- and di-phosphate (P2O7) 4- groups, and Mg/NiO6 octahedra, with Mg-O-P and Ni-O-P linkages.

Safety Evaluation of Oil Samples Collected from Different Food Points of Multan City of Pakistan

Cooking oil has become a part and parcel of modern food system and therefore its safety is of prime significance for health agencies around the globe to ensure good health among the community. Current study was designed to investigate the physicochemical properties including free fatty acids, peroxide value and conjugated dienes; minerals (nickel & cobalt) and heavy metals (lead and cadmium) in oil samples collected from different areas of Multan city of Pakistan. The findings of this study revealed that free fatty acid percentages, conjugated dienes, cobalt and nickel concentrations were in normal ranges while the peroxide values, lead and cadmium concentrations were recorded above the norms. Strict regulatory measures need to be adopted to ensure good quality oil supply and to protect the people from health implications of physicochemical and metallic hazards prevailing in fried oils and fried foods.

Low Activation-Modified High Manganese-Nitrogen Austenitic Stainless Steel for Fast Reactor Pressure Vessel Cladding

Low and free nickel austenitic stainless steel alloys were developed successfully and proposed to be used as a liquid sodium coolant fast reactor pressure vessel cladding. A standard austenitic stainless steel SS316L (AISI 316L) was produced as a reference sample. The nickel content was partially or totally replaced by manganese and nitrogen. The microstructure of the produced stainless steel alloys was investigated using Schaeffler diagram, optical microscopy and X-ray diffraction patterns (XRD). Mechanical properties of the developed stainless steel grads were investigated using Vickers hardness, impact and tensile tests at room temperature. Sodium chloride was used to study the corrosion rate of the investigated alloys by open circuit potential technique. Slow and total slow neutrons removal cross sections were measured using 241 Am-Be neutron source and highly calibrated He-3 detector. Eight gamma ray lines which emitted from 60 Co and 232 Th radioactive sources and HPGe detector were used to study the attenuation parameters of the produced alloys. Metallography, Schaeffler diagram and XRD results showed that all the produced stainless steels are mainly of austenite phase with a small ferrite phase. The developed manganese-nitrogen stainless steels showed higher hardness, yield and ultimate tensile strength than SS316L. The elongation of developed stainless steels is relatively lower than the standard SS316L. The impact toughness was reduced with replacement of Ni by Mn. The developed manganese stainless steels have a higher total slow removal cross section than SS316L. On the other hand, the slow neutron and gamma rays have nearly the same behavior for all studied stainless steels.

Cathodic process of nickel electrodeposition from ammonia–ammonium chloride solutions

Mechanism of cathodic process on nickel electrodeposition from ammonia–ammonium chloride solutions was studied by Tafel polarization curves, linear sweep voltammetry (LSV), cyclic voltammograms (CV) and chronopotentiometry (CE) technologies. In the electrolyte with 1.0 mol·L−1 NiCl2·6H2O, 4.0 mol·L−1 NH3·H2O and 2.5 mol·L−1 NH4Cl, nickel ion mainly complexed with ammonia and almost no free nickel ion could be found. It is confirmed that the dominant form of nickel ammonia complex ion in the system is Ni(NH3) 4 2+ by measuring the equilibrium potential of the electrode at various concentrations of ammonia. The species of Ni(NH3) 4 2+ turns into Ni(NH3) 2 2+ during pre-chemical reaction step before discharging reduction reaction. Then, Ni(NH3) 2 2+ discharges at the cathodic interface to form metal nickel deposit directly. Nucleation process is involved during nickel electrodeposition according to CV results. The reduction reaction of Ni(NH3) 2 2+ is irreversible which is controlled by diffusion step. Other processes are also accompanied during the electrodeposition process, except for the diffusion-controlled process.

Kinetic modeling of fatty acid methyl esters and triglycerides hydrodeoxygenation over nickel and palladium catalysts

The kinetics of fatty acids methyl esters (FAME) and triglycerides (TG) hydrodeoxygenation (HDO) over 5 wt% Ni/H-Y-80 and 5 wt% Pd/C catalysts into green-diesel range hydrocarbons was studied experimentally and modeled numerically. The liquid-phase HDO was performed in a semi-batch reactor at the reaction temperature of 300 °C and pressure 30 bar on a sulfur free nickel supported catalyst and a palladium catalyst for comparison.The fit of the model was evaluated by comparing the concentration profiles obtained from the model with the experimental data. The model confirmed that a complete reaction network involves hydrogenation, decarboxylation/decarbonylation and the direct hydrodeoxygenation of FA. Overall, the model displayed a good fitting for both studied substrates. Moreover, the model is expected to be applicable to different fatty acids. The rate constants for the conversion of FAME and TG, containing mixture of two groups of molecules C:16 and C:18, show dependence on the fatty acids carbon chain length.

On magnetism of nickel clusters in nanoporous carbon

The structural and magnetometric characteristics of a nanoporous carbon with nickel clusters in nanopores have been studied. The main attention is focused on the fact of substantial decrease in the nickel magnetization as nickel has a close contact to carbon as compared to similar parameter of free nickel microparticles with almost the same sizes. A theoretical model of a periodic cluster consisting of 16 carbon atoms and one nickel atom in a micropore surrounded by carbon atoms has been built. The electron density in such a cluster and its magnetism were found by computer calculations. It is shown that the magnetic moment of a nickel atom in the cluster is substantially smaller than that of a free nickel atom. Based on the results, it is concluded that the decrease in the magnetization of nickel clusters in the carbon environment observed experimentally is due to the adsorption interaction of the nickel and carbon electron subsystems.

Solvothermal synthesis of surfactant free spherical nickel hydroxide/graphene oxide composite for supercapacitor application

Spherical composite of Ni(OH)2/GO was produced via a surfactant free solvothermal technique and tested as electrode materials for electrochemical capacitors. The structural and morphological analysis confirmed that deposition of Ni(OH)2 onto GO does not change the crystal structure of pure hexagonal α-Ni(OH)2. Electrode fabricated from the Ni(OH)2/GO composite demonstrates a superior electrochemical performance when compared to that of pure Ni(OH)2, GO, and Mix-Ni(OH)2/GO electrodes with Ni(OH)2/GO electrode exhibiting a specific capacity of ∼420 mA h g−1 which correspond to a specific capacitance of 3619 F g−1 at 2.5 A g−1, as well as a corresponding rate capability of 78% at 10 A g−1. The stability study of the Ni(OH)2/GO composite reveals a good capacity retention of ∼95% at a current density of 10 A g−1 after 3000 charge-discharge cycles.

ADSORPTION OF IONS OF NICKEL (II) FROM WATER SOLUTIONS WITH CARBON ADSORBENTS

For citation:Dudarev V.I., Irinchinova N.V., Filatova E.G. Adsorption of ions of nickel (II) from water solutions with carbon adsorbents. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 1. P. 75-80.Adsorption methods of cleaning remains beyond comparison for deep extraction of heavy metal ions from dilute solutions. Their practical application allows achieving the high efficiency of wastewater treatment with minimal impact on the environment. It is known that nickel is one of carcinogenic elements. Thus, free nickel ions (II) are twice toxic than complex compounds. The maximum content of nickel ion (II) at the production of spent electroplating solutions is 50 mg/l, in washing waters – from 2 to 5 mg/l. In this paper we studied the adsorption capacity of carbon adsorbents IPI-T, synthesized from waste phenol-formaldehyde resin with respect to the nickel ions (II). Carbon аdsorbents IPI-T are black granules of irregular shape with an average particle size from 2 to 5 mm, and a surface area of 480 m2/g. Adsorption equilibrium time in static conditions corresponding to the constancy of the concentration of heavy metal ions in solution was four hours. A study of the adsorption capacity of carbon adsorbents IPI-T was performed at pH of 9.5. The adsorption process accompanied by the slight decrease in pH. Isotherms were build according to the results of research of adsorption at different temperatures. The shape of the isotherms obtained corresponds to poly-molecular adsorption. The resulting isotherms were processed using adsorption models of BET and Dubinin-Radushkevich. It was shown that the adsorption process model is best described by BET. Model Dubinin-Radushkevich was used to calculate the free energy of adsorption. The value of the free energy of adsorption indicates that the binding of nickel ion (II) has a physical nature. It was found that with the temperature increasing the adsorption capacity of carbon adsorbents IPI-T decreases. The dynamic activity of the adsorbent was characterized by the time of beginning of pass of the adsorbate till «breakthrough». Maximum protective effect of the adsorbent was 5 hours, and it was recovered 150 mg of nickel ions (II). The effectiveness of wastewater treatment of galvanic production from heavy metal ions was not less than 98%.

Highly efficient noble metal free copper nickel oxysulfide nanoparticles for catalytic reduction of 4-nitrophenol, methyl blue, and rhodamine-B organic pollutants

Novel and noble metal-free copper nickel oxysulfide nanoparticles have been successfully fabricated by using a simple, cost-effective, and eco-friendly solution-based approach, with copper oxysulfide as a comparative.

An unusual asymmetric pseudomacrocyclic free base ligand and nickel(II) chelate: X-ray crystallographic and DFT studies

A novel tetradentate dipyrrolidequinoxaline ligand, 5-(3-{5-[(E)-(propylimino)methyl]-1H-pyrrol-2-yl}quinoxaline-2-yl)-1H-pyrrole-2-carbaldehyde (H2L1) and its Ni(II) complex, 2-[3-(5-formyl-1H-pyrrol-2-yl)quinoxaline-2-yl]-5-(prpylimino)methyl]propyl-1-ide nickel(II), [Ni(L1)], have been synthesised and studied by X-ray crystallography. The asymmetric pseudomacrocyclic ligand, which has an unusual NN′N″O donor atom set, crystallised in the orthorhombic space group P212121. Interestingly, the X-ray data show that the ligand is present as a zwitterion in the solid state with the trans imine and pyrrole N-atoms protonated. The zwitterionic structure leads to two intramolecular hydrogen bonds with hydrogen bond lengths (D⋯A) for Npyrrole–H⋯Npyrrole and Nimine–H⋯Oaldehyde which measure 2.591(2) and 2.836(2)Å, respectively. The Ni(II) chelate crystallises in the monoclinic space group Cc and adopts a square planar coordination geometry. DFT-simulated structures of both H2L1 and [Ni(L1)] in vacuo are in good agreement with those obtained experimentally in the solid state with RMSDs of 0.1710Å and 0.3214Å, respectively. DFT studies showed that the experimentally determined zwitterionic structure of H2L1 is significantly lower in energy than the other possible canonical forms. ESP maps provide insight into the hydrogen bonding patterns of the ligand. TD-DFT calculations were used to delineate the experimental UV–Vis spectra.

Nickel based mesoporous silica-ceria-zirconia composite for carbon dioxide reforming of methane

A series of mesoporous silica-ceria-zirconia composite (Si-MCeZr) with variable Si/(Ce+Zr) molar ratios are prepared by improved evaporation induced self-assemble strategy (EISA). TEM and XRD measurements show that the Si-MCeZr frameworks are made of ceria-zirconia solid solutions crystalline nanoparticles and the amorphous silica that serves as glue connecting the nanocrystals. The further heating treatment (700°C) reveals that the thermal stability of Si-MCeZr is higher than that of Si free mesoporous ceria-zirconia solid solution (MCeZr). This might be due to the key role of the introduction of Si, which improves the thermal stability via inhibiting the growth of nanoparticles and crystallization of ceria-zirconia solid solution nanoparticles. Furthermore, the Si-MCeZr materials are applied as support to prepare nickel based catalysts (Ni/Si-MCeZr) for CO2 reforming of CH4. The XPS analyses show that the concentration of surface oxygen vacancies in Ni/Si-MCeZr increases with the increasing of Si/(Ce+Zr) molar ratios. The long term reforming test demonstrates that the catalytic stability of Ni/Si-MCeZr is improved compared to Si free nickel based catalyst (Ni/MCeZr). The obtained results indicate that enhanced durability may originate from the higher concentration of oxygen vacancies, more rapid oxygen mobility and improved nickel dispersion in Ni/Si-MCeZr, which contribute largely to higher catalytic activity and decoking ability in reforming reaction, as confirmed by TG-DSC and XRD characterizations of catalysts before and after stability tests.

Metallic nickel nanoparticles and their effect on the embryonic development of the sea urchin Paracentrotus lividus

The presence of nanoparticles in many industrial applications and daily products is making it nowadays crucial to assess their impact when exposed to the environment. Metallic nickel nanoparticles (Ni NPs) are of high industrial interest due to their ability to catalyze the reversible hydration of CO2 to carbonic acid at ambient conditions. We characterized metallic Ni NPs by XRD, HRTEM and EDS and determined the solubility of free nickel ions from 3 mg/L metallic Ni NPs in seawater by ICP-MS over 96 h, which was below 3%. Further, embryonic development of the sea urchin Paracentrotus lividus was investigated for 48 h in the presence of metallic Ni NPs (0.03 mg/L to 3 mg/L), but no lethal effects were observed. However, 3 mg/L metallic Ni NPs caused a size reduction similar to 1.2 mg/L NiCl2*6 H2O. The obtained results contribute to current studies on metallic Ni NPs and point to their consequences for the marine ecosystem.

High energy and power density Li–O2 battery cathodes based on amorphous RuO2 loaded carbon free and binderless nickel nanofoam architectures

A binder-less and carbon-free Ni nanofoam decorated with amorphous RuO2 nanoflakes was utilized as an innovative cathode in a Li–O2 battery.

Investigation on structural and electrochemical properties of binder free nanostructured nickel oxide thin film

Here, we report a simple method to achieve binder free nickel oxide (NiO) thin film using an electrohydrodynamic atomization (EHDA) process. The optimization of process parameters to obtain uniform thin film is discussed in detail. The high surface purity of nanostructured NiO film is oriented in the face centered cubic structure. The surface morphology revealed uniform deposition of anisotropic nanoplatelets morphology. The cyclic voltammetry and electrochemical impedance spectroscopy confirm the pseudocapacitance behavior of NiO film with a specific capacitance of 178F/g. The cyclic test exhibits a good cyclic retention of 94% for 1200 cycles.

The Carbon Monoxide Dehydrogenase from Desulfovibrio vulgaris

Ni-containing Carbon Monoxide Dehydrogenases (CODHs) catalyze the reversible conversion between CO and CO2 and are involved in energy conservation and carbon fixation. These homodimeric enzymes house two NiFeS active sites (C-clusters) and three accessory [4Fe–4S] clusters. The Desulfovibrio vulgaris (Dv) genome contains a two-gene CODH operon coding for a CODH (cooS) and a maturation protein (cooC) involved in nickel insertion in the active site. According to the literature, the question of the precise function of CooC as a chaperone folding the C-cluster in a form which accommodates free nickel or as a mere nickel donor is not resolved. Here, we report the biochemical and spectroscopic characterization of two recombinant forms of the CODH, produced in the absence and in the presence of CooC, designated CooS and CooSC, respectively. CooS contains no nickel and cannot be activated, supporting the idea that the role of CooC is to fold the C-cluster so that it can bind nickel. As expected, CooSC is Ni-loaded, reversibly converts CO and CO2, displays the typical Cred1 and Cred2 EPR signatures of the C-cluster and activates in the presence of methyl viologen and CO in an autocatalytic process. However, Ni-loaded CooSC reaches maximum activity only upon reductive treatment in the presence of exogenous nickel, a phenomenon that had not been observed before. Surprisingly, the enzyme displays the Cred1 and Cred2 signatures whether it has been activated or not, showing that this activation process of the Ni-loaded Dv CODH is not associated with structural changes at the active site.

Electrodeposition of a nickel coating from a low-temperature acetate-chloride nickel-plating electrolyte

The effect of the electrocrystallization conditions on the microstructure and growth direction of a nickel coating obtained from acetate-chloride nickel-plating electrolytes was considered. The distribution of the forms of complex ions in solution was evaluated using a mathematical model. The positively charged species in the electrolyte amounted to 18–31%, which significantly affected the mass transfer. An increase in the concentration of acetate ions promoted the formation of Ni(CH3COO)+ and Ni(CH3COO)2 and decreased the content of free nickel ions in the electrolyte, leading to a decrease in polarization and shifting the polarization curves toward higher electropositive values. The structure of the coating is most strongly affected by variation of current density, but not of electrolyte composition.

Determination of very low amounts of free copper and nickel ions in beverages and water samples using cloud point extraction assisted by silver nanoparticles

Silver nanoparticles act as carriers in the transfer of copper and nickel ions to the surfactant-rich phase obtained in a CPE process.

Failure of total hip implants: metals and metal release in 52 cases.

The pathogenesis of total joint replacement failure is multifactorial. One hypothesis suggests that corrosion and wear of alloys result in metal ion release, which may then cause sensitization and even implant failure, owing to the acquired immune reactivity. To assess cobalt, nickel and chromium(VI) release from, and the metal composition of, failed metal-on-ethylene total hip replacements. Implant components from 52 revision cases were evaluated with spot tests for free nickel, cobalt, and chromium (VI) ions. Implant composition was determined with X-ray fluorescence spectroscopy, and information on the reason for revision and complications in relation to surgery was collected from the medical charts when possible (72%). For 10 implants, corrosion was further characterized with scanning electron microscopy. We detected cobalt release from three of 38 removed femoral heads and from one of 24 femoral stems. Nickel release was detected from one of 24 femoral stems. No chromium(VI) release was detected. We found that cobalt and nickel were released from some failed total hip arthroplasties, and corrosion was frequently observed. Metal ions and particles corroded from metal-on-polyethylene may play a role in the complex aetiopathology of implant failure.

Remediation of aquatic environment contaminated with the iminodiacetic acid metal complexes using ferrate(VI)

The aim of this investigation is to assess the applicability of ferrate(VI) in the treatment of M(II)-complexed species viz., Cd(II)-IDA and Ni(II)-IDA from aqueous solutions. The batch reactor operations are performed for various physico-chemical parametric studies. The batch reactor studies indicate that a fast and efficient decomplexation/removal of Cd(II)/Ni(II)-IDA is occurred at varied molar concentrations (0.3–10.0mmol/L) of the complexed species treated with a constant dose of Fe(VI) (i.e., 1.0mmol/L). Moreover, decreasing the pH values from 10.0 to 8.0 is further favored the decomplexation/degradation of these pollutant species. The time dependence data is utilized further in demonstrating the kinetic studies conducted for various molar ratios of M(II)-IDA to Fe(VI) as studied at different pH values (i.e., pH 10.0–8.0). The kinetic results show that the decomplexation/oxidation of complexed species is followed with pseudo-first and pseudo-second order rate kinetics for both the systems studied. Further, these results indicate that the rate of decomposition is followed with first order rate kinetics for both the reactants i.e., Fe(VI) and M(II)-IDA species. This infers that a 1:1 stoichiometry prevails to the decomposition M(II)-IDA species by Fe(VI). The overall rate constant values indicate that decreasing the pH causes to increase the rate of degradation/decomplexation of M(II)-IDA by Fe(VI). Decomplexation/oxidation of the complexes shows that a significant degradation/oxidation of the IDA occurred since a significant decrease in total organic carbon (TOC) is obtained. Again, lower pH values favor the oxidation/mineralization of IDA. Remarkably, a significant removal of free cadmium or nickel is obtained simultaneously. The removal of metal ions is further enhanced raising the pH of the Fe(VI) treated samples to 12.0 and almost 100% of Cd(II) was removed whereas a significant percent of Ni(II) was also removed. These results indicate that the treatment of aqueous wastes contaminated with M(II)-IDA is efficient and effective by Fe(VI).

Autocatalytic duplex Ni–P/Ni–W–P coatings on AZ31B magnesium alloy

Autocatalytic duplex Ni–P/Ni–W–P coatings were deposited on AZ31B magnesium alloy using stabilizer free nickel carbonate bath. Some of the coated specimens were passivated in chromate solution with and without heat treatment. Plain Ni–P coatings were also prepared for comparison. Coatings were characterized for their surface morphology, composition and corrosion resistance. Energy dispersive analysis of X-ray (EDX) showed that the phosphorous content in the Ni–P coating is 6wt.% and for Ni–W–P it reduced to 3wt.% due to the codeposition of tungsten in the Ni–P coating. Marginal increase in P and W contents was observed on passivated coupons along with Cr (0.18wt.%) and O (2.8wt.%) contents. Field emission scanning electron microscopy (FESEM) examination of these coating surfaces exhibited the nodular morphology. Chromate passivated surfaces showed the presence of uniformly distributed bright Ni particles along with nodules. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) studies were carried out in deaerated 0.15M NaCl solution to find out the corrosion resistance of the coatings. Among the coatings developed, duplex-heat treated-passivated (duplex-HTP) coatings showed lower corrosion current density (icorr) and higher polarization resistance (Rp) indicating the improved corrosion resistance. The charge transfer resistance (Rct) value obtained for the duplex-HTP was about 170 times higher compared to that for Ni−P coating.