Cobalt‐Free High‐Capacity Ni‐Rich Layered Li[Ni0.9Mn0.1]O2 Cathode

Li[Ni_0.9Co_0.1]O₂ (NC90), Li[Ni_0.9Co_0.05Mn_0.05]O₂ (NCM90), and Li[Ni_0.9Mn_0.1]O₂ (NM90) cathodes are synthesized for the development of a Co‐free high‐energy‐density cathode. NM90 maintains better cycling stability than the two Co‐containing cathodes, particularly under harsh cycling conditions (a discharge capacity of 236 mAh g^?1 with a capacity retention of 88% when cycled at 4.4 V under 30 °C and 93% retention when cycled at 4.3 V under 60 °C after 100 cycles). The reason for the enhanced stability is mainly the ability of NM90 to absorb the strain associated with the abrupt anisotropic lattice contraction/extraction and to suppress the formation of microcracks, in addition to enhanced chemical stability from the increased presence of stable Mn⁴⁺. Although the absence of Co deteriorates the rate capability, this can be overcome as the rate capability of the NM90 approaches that of the NCM90 when cycled at 60 °C. The long‐term cycling stability of NM90 is confirmed in a full cell, demonstrating that it is one of the most promising Co‐free cathodes for high‐energy‐density applications. This study not only provides insight into redefining the role of Mn in a Ni‐rich cathode, it also represents a clear breakthrough in achieving a commercially viable Co‐free Ni‐rich layered cathode.     

IMMOBILIZATION OF BOVINE CATALASE ONTO MAGNETIC NANOPARTICLES

The scope of this study is to achieve carrier-bound immobilization of catalase onto magnetic particles (Fe₃O₄ and Fe₂O₃NiO₂ · H₂O) to specify the optimum conditions of immobilization. Removal of H₂O₂ and the properties of immobilized sets were also investigated. To that end, adsorption and then cross-linking methods onto magnetic particles were performed. The optimum immobilization conditions were found for catalase: immobilization time (15 min for Fe₃O₄; 10 min for Fe₂O₃NiO₂ · H₂O), the initial enzyme concentration (1 mg/mL), amount of magnetic particles (25 mg), and glutaraldehyde concentration (3%). The activity reaction conditions (optimum temperature, optimum pH, pH stability, thermal stability, operational stability, and reusability) were characterized. Also kinetic parameters were calculated by Lineweaver–Burk plots. The optimum pH values were found to be 7.0, 7.0, and 8.0 for free enzyme, Fe₃O₄-immobilized catalases, and Fe₂O₃NiO₂ · H₂O-immobilized catalases, respectively. All immobilized catalase systems displayed the optimum temperature between 25 and 35°C. Reusability studies showed that Fe₃O₄-immobilized catalase can be used 11 times with 50% loss in original activity, while Fe₂O₃NiO₂ · H₂O-immobilized catalase lost 67% of activity after the same number of uses. Furthermore, immobilized catalase systems exhibited improved thermal and pH stability. The results transparently indicate that it is possible to have binding between enzyme and magnetic nanoparticles.     

Selective Divalent Cobalt Ions Detection Using Ag2O3-ZnO Nanocones by ICP-OES Method for Environmental Remediation

Here, we have synthesized Ag₂O₃-ZnO nanocones (NCs) by a wet-chemical route using reducing agents at low temperature. The structural, optical and morphological properties of Ag₂O₃-ZnO NCs were investigated by several conventional techniques such as powder XRD, XPS, FESEM, XEDS, FTIR and UV/vis. spectroscopy. The analytical parameters of prepared NCs were also calculated for a selective detection of divalent cobalt [Co(II)] prior to its determination by inductively coupled plasma-optical emission spectrometry (ICP-OES). The selectivity of NCs toward various metal ions, including Cd(II), Co(II), Cr(III), Cu(II), Fe(III), Ni(II), and Zn(II) was studied. Results of the selectivity study demonstrated that Ag₂O₃-ZnO NC phase was the most selective towards Co(II) ion. The uptake capacity for Co(II) ion was experimentally calculated to be ∼76.69 mgg⁻¹. Moreover, adsorption isotherm data provided that the adsorption process was mainly monolayer on homogeneous adsorbent surfaces of Ag₂O₃-ZnO NCs. Kinetic study revealed that the adsorption of Co(II) on Ag₂O₃-ZnO NCs phase followed the pseudo-second-order kinetic model. In addition, thermodynamic results provided that the adsorption mechanism of Co(II) ions on Ag₂O₃-ZnO NCs was a spontaneous process and thermodynamically favorable. Finally, the proposed method was validated by applying it to real environmental water samples with reasonable results.     

Effect of annealing on down‐conversion properties of monoclinic Gd2O3:Er3+ nanophosphors

Erbium‐doped nano‐sized Gd₂O₃ phosphor was prepared by a solution combustion method in the presence of urea as a fuel. The phosphor was characterized by X‐ray diffractometry (XRD), Fourier transform infra‐red spectroscopy, energy dispersive X‐ray analysis (EDX) and transmission electron microscopy (TEM). The results of the XRD shows that the phosphor has a monoclinic phase, which was further confirmed by the TEM results. Particle size was calculated by the Debye–Scherrer formula. The erbium‐doped Gd₂O₃ nanophosphor was revealed to have good down‐conversion (DC) properties and the intensity of phosphor could be modified by annealing. The effects of annealing at 900°C on the particle size and luminescence properties were studied and compared with freshly prepared Gd₂O₃:Er³⁺ nanoparticles. The average particle sizes were calculated as 8 and 20 nm for the freshly prepared samples and samples annealed at 900°C for 1 h, respectively. The results show that both freshly prepared and annealed Gd₂O₃:Er³⁺ have monoclinic structure. Copyright © 2014 John Wiley & Sons, Ltd.     

Removal of Co by carbonaceous material obtained through solution combustion of tamarind shell

New carbonaceous materials were obtained through solution combustion process of tamarind shell in the presence of urea and ammonium nitrate, and all of them were tested for Co removal. The effect of temperature (from 600 to 1000°C) and water volume on surface texture of carbonaceous material and its adsorptive capacity was evaluated. Scanning electron microscope, Fourier transform infrared spectroscopy, X-ray powder diffraction, and Brunauer–Emmett–Teller (BET) model were used to characterize the obtained carbonaceous material before applying for the removal of cobalt. The point of zero charge was also determined. The results indicate that BET-specific surface areas ranged from 6.40 to 216.72 m²g^?1 for the carbonaceous materials obtained at 600, 700, 800, 900, and 1000°C. The one obtained at 900°C (CombTSF₉₀₀) was found to be the most effective adsorbent for the removal of Co(II) ions from aqueous solutions, with a maximum sorption capacity (Q_max) of 43.56 mg/g. Carbonaceous material obtained through the solution combustion process improves morphological characteristics of adsorbent in a short time, and could be used as an alternative method for the removal of cobalt.     

Spatio-temporal patterns of grassland evapotranspiration and water use efficiency in arid areas

Understanding spatio-temporal patterns of grassland evapotranspiration (ET) and water use efficiency (WUE) in arid areas is important for livestock production and ecological conservation. Xinjiang, China, was used as an example in the Biome-BGC model to explore spatio-temporal patterns of grassland ET and WUE from 1979 to 2012 in arid areas. The ET ranked from high to low as follows: among seasons, summer (142.4 mm), spring (49.7 mm), autumn (45.9 mm) and winter (7.7 mm); among regions, the Tianshan Mountains (357.9 mm), northern Xinjiang (221.3 mm) and southern Xinjiang (183.2 mm); among grassland types, mid-mountain meadow (387.7 mm), swamp meadow (358.3 mm), typical grassland (343.9 mm), desert grassland (236.2 mm), alpine meadow (229.7 mm), and saline meadow (154.7 mm). The WUE ranked from high to low as follows: among seasons, summer (0.60 g C kg H₂O^?1), autumn (0.48 g C kg H₂O^?1) and spring (0.43 g C kg H₂O^?1); among regions, northern Xinjiang (0.73 g C kg H₂O^?1), the Tianshan Mountains (0.69 g C kg H₂O^?1) and southern Xinjiang (0.26 g C kg H₂O^?1); among grassland types, mid-mountain meadow (0.86 g C kg H₂O^?1), typical grassland (0.84 g C kg H₂O^?1), swamp meadow (0.77 g C kg H₂O^?1), saline meadow (0.52 g C kg H₂O^?1), alpine grassland (0.37 g C kg H₂O^?1) and desert grassland (0.34 g C kg H₂O^?1). In Xinjiang grasslands, the spatio-temporal ET patterns were more strongly influenced by precipitation than by temperature, whereas most high WUE values occurred when precipitation and temperature were relatively conducive to grass growth.     

The Effects of Exogenous Ascorbic Acid on the Mechanism of Physiological and Biochemical Responses to Nitrate Uptake in Two Rice Cultivars (<Emphasis Type="Italic">Oryza sativa</Emphasis> L.) Under Aluminum Stress

As a major antioxidant in plants, ascorbic acid (AsA) plays a very important role in the response to aluminum (Al) stress. However, the effect of AsA on the mitigation of Al toxicity and the mechanism of nitrate nitrogen (NO₃ ^?–N) uptake by plants under Al stress are unclear. In this study, a hydroponic experiment was conducted using peak 1 A rice (sterile line, Indica) with weaker resistance to Al and peak 1 superior 5 rice (F1 hybrid, Indica) with stronger resistance to Al to study the effects of exogenous AsA on the physiological and biochemical responses to NO₃ ^?–N uptake by rice roots exposed to 50 μmol L^?1 Al. Al stress induced increases in the concentrations of H₂O₂ and malondialdehyde (MDA) and in the activities of antioxidant enzymes [such as superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX)]. Plasma membrane (PM) H⁺-ATPase and H⁺-pump activities, endogenous AsA content and NO₃ ^?–N uptake in rice roots decreased under Al stress. After treatment with 2 mmol L^?1 exogenous AsA combined with Al, concentrations of H₂O₂ and MDA in roots notably decreased, and endogenous AsA content and activities of SOD, POD, CAT, and APX in rice roots increased significantly; furthermore, the interaction of PM H⁺-ATPase and the 14-3-3 protein was also enhanced significantly compared with that in control plants without AsA treatment, which clearly increased NO₃ ^?–N uptake. Based on all of these data, the application of AsA significantly reduced the accumulation of H₂O₂ and MDA and increased the activities of PM H⁺-ATPase and the H⁺-pump by increasing the endogenous AsA content, the antioxidant enzyme activities, and the interaction of PM H⁺-ATPase and the 14-3-3 protein in the roots of the two rice cultivars under Al stress, thereby improving the uptake of NO₃ ^?–N in rice.     

Characteristics of Nitrate Reduction Using Fe (II) as Electron Donor in Activated Sludge

Static experiments were conducted to investigate the effects of environmental factors on nitrate (NO₃^?-N)-removal efficiency, such as NO₃^?-N loading, pH value, C/N ratio and temperature in activated sludge using Fe (II) as electron donor. The results demonstrated that the average denitrification rate increased from 1.25 to 2.23 mg NO₃^?-N/(L·h) with NO₃^?-N loading increased from 30 to 60 mg/L. When pH increased from 7 to 8, the concentration of NO₃^?-N and nitrite (NO₂^?-N) in effluent were all maintained at quite low levels. C/N ratio had little impact on denitrification process, i.e., inorganic carbon (C) source could still be enough for denitrification process with C/N ratio as low as 5. Temperature had a significant effect on the denitrification efficiency, and NO₃^?-N removal efficiency of 92.03%, 96.77%, 97.67% and 98.23% could be obtained with temperature of 25°C, 30°C, 35°C and 40°C, respectively. SEM, XRD and XRF analysis was used to investigate microscopic surface morphology and chemical composition of the denitrifying activated sludge, and mechanism of the nitrate-dependent anaerobic ferrous oxidation (NAFO) bacterias could be explored with this research.     

Effect of Coronatine on Antioxidant Enzyme Response of Chickpea Roots to Combination of PEG-Induced Osmotic Stress and Heat Stress

Abiotic stresses, such as high temperature and drought, are major limiting factors of crop production and growth. Coronatine (COR), a structural and functional analog of jasmonates, is suggested to have a role in abiotic stress tolerance. The aim of our study was to examine whether pretreatment with COR enhances the tolerance of chickpea (Cicer arietinum L. cv ICC 4958) roots to PEG-induced osmotic stress, heat stress, and their combination. Therefore, seedlings raised hydroponically in a growth chamber for 15 days were pretreated with or without COR at 0.01 μM for 24 h and then exposed to 6 % PEG 6000-induced osmotic stress or heat (starting at 35 °C and then gradually increased 1 °C every 15 min and kept at 44 °C for 1 h) stress for 3 days. After different treatment periods, the changes in relative growth rate (RGR); malondialdehyde (MDA), proline (Pro), and hydrogen peroxide (H₂O₂) contents; and the activities of antioxidant enzymes/isoenzymes in roots of chickpea seedlings with or without 0.01 μM COR application were studied. RGR in roots was increased by COR application. Under all stress conditions, H₂O₂, MDA, and Pro levels increased sharply, but pretreatment with COR significantly reduced them. Moreover, COR increased the activities of H₂O₂ scavenger enzymes such as catalase (CAT) under heat stress, ascorbate peroxidase (POX) under PEG stress, and CAT and POX under combined stresses. Therefore, COR might alleviate adverse effects of PEG stress and heat stress and combined stresses on roots of chickpea by reduction of H₂O₂ production, enhancing or keeping the existent activity of antioxidant enzymes, thereby preventing membrane peroxidation.     

Growth of Salvinia molesta as affected by water temperature and nutrition I. Effects of nitrogen level and nitrogen compounds

The growth of Salvinia molesta D.S. Mitchell was studied in a greenhouse using controlled-temperature water-baths at 16, 19 and 22°C and 4 different nitrogen compounds (NO₃^?, NH₄⁺, NH₄NO₃ and urea) at levels up to 60 mg N l^?1. Little growth occurred at 16°C even if 20 mg N l^?1 was supplied together with other nutrients including phosphorus (2 mg H₂PO₄-P l^?1). The highest relative growth rate and total dry matter production occurred at 22°C when plants were supplied with 20 mg NH₄-N l^?1. At this temperature, the NH₄⁺ ion was superior to the NO₃^? ion or urea as a nitrogen source (almost doubling the biomass), but was not significantly better than NH₄NO₃. Over a period of 19 days for plants receiving 0.02 mg NH₄-N l^?, biomass increased 4-fold at 16°C, 9-fold at 19°C and 10-fold at 22°C. In contrast, for plants receiving 20 mg NH₄-N l^?1, biomass increased 4-fold at 16°C, 18-fold at 19°C and 38-fold at 22°C.     

New binary copper(II) complexes containing intercalating ligands: DNA interactions,an unusual static quenching mechanism of BSA and cytotoxic activities

New binary copper(II) complexes – [Cu(4-mphen)₂(NO₃)]NO₃·H₂O (1), [Cu(5-mphen)₂ (NO₃)]NO₃·H₂O (2), the known complex [Cu(dmphen)₂(NO₃)]NO₃ (3) and [Cu(tmphen)₂ (NO₃)]NO₃·H₂O (4) - (4-mphen: 4-methyl-1,10-phenanthroline, 5-mphen: 5-methyl-1,10-phenanthroline, dmphen: 4,7-dimethyl-1,10-phenanthroline, tmphen: 3,4,7,8-tetramethyl-1,10-phenanthroline), have been synthesized and characterized by CHN analysis, ESI-MS, FTIR and single-crystal X-ray diffraction techniques. Interaction of these complexes with calf thymus DNA (CT-DNA) has been investigated by absorption spectral titration, ethidium bromide (EB) and Hoechst 33,258 displacement assay and thermal denaturation measurement. These complexes cleaved pUC19 plasmid DNA in the absence and presence of an external agent. Notably, in the presence of H₂O₂ as an activator, the cleavage abilities of these complexes are obviously enhanced at low concentration. Addition of hydroxyl radical scavengers like DMSO shows significant inhibition of the DNA cleavage activity of these complexes. BSA quenching mechanism was investigated with regard to the type of quenching, binding constant, number of binding locations and the thermodynamic parameters. The experimental results suggested that the probable quenching mechanism was an unusual static process and hydrophobic forces play a dominant role. The CT-DNA and BSA binding efficiencies of these complexes follow the order: 4 > 3 > 1 > 2. Furthermore, in vitro cytotoxicities of these complexes on tumor cells lines (Caco-2, MCF-7 and A549) and healthy cell line (BEAS-2B) showed that these complexes exhibited anticancer activity with low IC₅₀ values. The effect of hydrophobicity of the methyl-substituted phenanthrolines on DNA and protein binding activities of these complexes is discussed.     

Coordination chemistry of lanthanides with cryptands. An X-ray and spectroscopic study of the complex Nd2(NO3)6 [C18H36O6N2]·H2O

By reacting neodymium nitrate hexahydrate with the cryptand 〈222〉 in methanol, the complex Nd₂-(NO₃)₆[C₁₈H₃₆O₆N₂]·H₂O was obtained and analyzed by single-crystal X-ray diffraction. The cell is triclinic P$\text{1}$ with a = 14.870(2) Å, b = 13.261(2) Å, c = 8.832(1) Å, α = 91.2(1)°, β = 93.4(1)°, γ = 87.6(1)°, Z = 2 and U = 1736.6 ų. The structure was refined by least-squares methods to the conventional R = 0.039 for 6177 observed reflections. The compound contains the cations [Nd〈222〉(NO₃)]²⁺ and the anions [Nd(NO₃)₅·H₂O]^2?, and is isostructural with the samarium analogue. Solid state fluorescence spectra of the title complex were measured at room and liquid nitrogen temperature, and the transitions ⁴F_3/2 → ⁴I_9/2 and ⁴F_3/2 → ⁴I_11/2 analyzed.     

Influence of bioturbation on denitrification and dissimilatory nitrate reduction to ammonium (DNRA) in freshwater sediments

Intensive agriculture leads to increased nitrogen fluxes (mostly as nitrate, NO₃ ^?) to aquatic ecosystems, which in turn creates ecological problems, including eutrophication and associated harmful algal blooms. These problems have focused scientific attention on understanding the controls on nitrate reduction processes such as denitrification and dissimilatory nitrate reduction to ammonium (DNRA). Our objective was to determine the effects of nutrient-tolerant bioturbating invertebrates (tubificid oligochaetes) on nitrogen cycling processes, specifically coupled nitrification–denitrification, net denitrification, DNRA, and biogeochemical fluxes (O₂, NO₃ ^?, NH₄ ⁺, CO₂, N₂O, and CH₄) in freshwater sediments. A mesocosm experiment determined how tubificid density and increasing NO₃ ^? concentrations (using N¹⁵ isotope tracing) interact to affect N cycling processes. At the lowest NO₃ ^? concentration and in the absence of bioturbation, the relative importance of denitrification to DNRA was similar (i.e., 49.6 and 50.4 ± 8.1 %, respectively). Increasing NO₃ ^? concentrations in the control cores (without fauna) stimulated denitrification, but did not enhance DNRA, which significantly altered the relative importance of denitrification compared to DNRA (94.6 vs. 5.4 ± 0.9 %, respectively). The presence of tubificid oligochaetes enhanced O₂, NO₃ ^?, NH₄ ⁺ fluxes, greenhouse gas production, and N cycling processes. The relative importance of denitrification to DNRA shifted towards favoring denitrification with both the increase in NO₃ ^? concentrations and the increase of bioturbation activity. Our study highlights that understanding the interactions between nutrient-tolerant bioturbating species and nitrate contamination is important for determining the nitrogen removal capacity of eutrophic freshwater ecosystems.     

Ni‐Rich Layered Cathode Materials with Electrochemo‐Mechanically Compliant Microstructures for All‐Solid‐State Li Batteries

While Ni‐rich cathode materials combined with highly conductive and mechanically sinterable sulfide solid electrolytes are imperative for practical all‐solid‐state Li batteries (ASLBs), they suffer from poor performance. Moreover, the prevailing wisdom regarding the use of Li[Ni,Co,Mn]O₂ in conventional liquid electrolyte cells, that is, increased capacity upon increased Ni content, at the expense of degraded cycling stability, has not been applied in ASLBs. In this work, the effect of overlooked but dominant electrochemo‐mechanical on the performance of Ni‐rich cathodes in ASLBs are elucidated by complementary analysis. While conventional Li[Ni_0.80Co_0.16Al_0.04]O₂ (NCA80) with randomly oriented grains is prone to severe particle disintegration even at the initial cycle, the radially oriented rod‐shaped grains in full‐concentration gradient Li[Ni_0.75Co_0.10Mn_0.15]O₂ (FCG75) accommodate volume changes, maintaining mechanical integrity. This accounts for their different performance in terms of reversible capacity (156 vs 196 mA h g^?1), initial Coulombic efficiency (71.2 vs 84.9%), and capacity retention (46.9 vs 79.1% after 200 cycles) at 30 °C. The superior interfacial stability for FCG75/Li₆PS₅Cl to for NCA80/Li₆PS₅Cl is also probed. Finally, the reversible operation of FCG75/Li ASLBs is demonstrated. The excellent performance of FCG75 ranks at the highest level in the ASLB field.     

Catalase catalyzes nitrotyrosine formation from sodium azide and hydrogen peroxide

Sodium azide (NaN₃) is known as an inhibitor of catalase, and a nitric oxide (NO) donor in the presence of catalase and H₂O₂. We showed here that catalase-catalyzed oxidation of NaN₃ can generate reactive nitrogen species which contribute to tyrosine nitration in the presence of H₂O₂. The formation of free-tyrosine nitration and protein-bound tyrosine nitration by the NaN₃/catalase/H₂O₂ system showed a maximum level at pH 6.0. Free-tyrosine nitration induced by peroxynitrite was inhibited by ethanol and dimethyl-sulfoxide (DMSO), and augmented by superoxide dismutase (SOD). However, free-tyrosine nitration induced by the NaN₃/catalase/H₂O₂ system was not affected by ethanol, DMSO and SOD. NO^-₂ and NO donating agents did not affect free-tyrosine nitration by the NaN₃/catalase/H₂O₂ system. The reaction of NaN₃ with hydroxyl radical generating system showed free-tyrosine nitration, but no formation of nitrite and nitrate. The generation of nitrite (NO^-₂) and nitrate (NO^-₃) by the NaN₃/catalase/H₂O₂ system was maximal at pH 5.0. These results suggested that the oxidation of NaN₃ by the catalase/H₂O₂ system generates unknown peroxynitrite-like reactive nitrogen intermediates, which contribute to tyrosine nitration.     

HYDROGEN PEROXIDE AND ECDYSONE IN THE CRYOPROTECTIVE DEHYDRATION STRATEGY OF Megaphorura Arctica (ONYCHIURIDAE: COLLEMBOLA)

The Arctic springtail, Megaphorura arctica, survives sub‐zero temperatures in a dehydrated state via trehalose‐dependent cryoprotective dehydration. Regulation of trehalose biosynthesis is complex; based in part on studies in yeast and fungi, its connection with oxidative stress caused by exposure of cells to oxidants, such as hydrogen peroxide (H₂O₂), or dehydration, is well documented. In this respect, we measured the amount of H₂O₂ and antioxidant enzyme activities (superoxide dismutases: copper, zinc—CuZnSOD and manganese containing–MnSOD, and catalase—CAT), as the regulatory components determining H₂O₂ concentrations, in Arctic springtails incubated at 5 °C (control) versus ?2 °C (threshold temperature for trehalose biosynthesis). Because ecdysone also stimulates trehalose production in insects and regulates the expression of genes involved in redox homeostasis and antioxidant protection in Drosophila, we measured the levels of the active physiological form of ecdysone—20‐hydroxyecdysone (20‐HE). Significantly elevated H₂O₂ and 20‐HE levels were observed in M. arctica incubated at ?2 °C, supporting a link between ecdysone, H₂O₂, and trehalose levels during cryoprotective dehydration. CAT activity was found to be significantly lower in M. arctica incubated at ?2 °C versus 5 °C, suggesting reduced H₂O₂ breakdown. Furthermore, measurement of the free radical composition in Arctic springtails incubated at 5 °C (controls) versus ?2 °C by Electron Paramagnetic Resonance spectroscopy revealed melanin‐derived free radicals at ?2 °C, perhaps an additional source of H₂O₂. Our results suggest that H₂O₂ and ecdysone play important roles in the cryoprotective dehydration process in M. arctica, linked with the regulation of trehalose biosynthesis.     

Ferroglobus placidus gen. nov., sp. nov., a novel hyperthermophilic archaeum that oxidizes Fe2+ at neutral pH under anoxic conditions

A novel coccoid, anaerobic, Fe²⁺-oxidizing archaeum was isolated from a shallow submarine hydrothermal system at Vulcano, Italy. In addition to ferrous iron, H₂ and sulfide served as electron donors. NO₃ ^– was used as electron acceptor. In the presence of H₂, also S₂O₃ ^2– could serve as electron acceptor. The isolate was a neutrophilic hyperthermophile that grew between 65° C and 95° C. It represents a novel genus among the Archaeoglobales that we name Ferroglobus. The type species is Ferroglobus placidus (DSM 10642). Received: 7 March 1996 / Accepted: 4 September 1996     

Sheet and chain polymeric transition metal complexes formed by N,N-o-phenylenedimethylenebis(pyridin-4-one)

The preparations are reported of the ‘extended reach’ ligand N,N^′-o-phenylene-dimethylenebis(pyridin-4-one) (o-XBP4) and of a range of its metal complexes with Mn(II), Co(II), Ni(II), Cu(II) and Zn(II), two of which have been shown by X-ray studies to have polymeric structures. In the compound [Mn(o-XBP4)(H₂O)₂(NO₃)](NO₃) the o-XBP4 ligands link ‘Mn(H₂O)₂(NO₃)’ units into chains which are then cross-linked into sheets by the bridging action of the coordinated nitrate. In [Cu(o-XBP4)(NO₃)₂] chains are also formed by the bridging action of the o-XBP4 ligands but here they simply pack trough-in-trough with no nitrate cross-linking. X-band EPR spectra are reported for these and the other Mn and Cu compounds as are relevant spectroscopic results for the other complexes.     

High‐Temperature Treatment of Li‐Rich Cathode Materials with Ammonia: Improved Capacity and Mean Voltage Stability during Cycling

Li‐rich electrode materials of the family x Li₂MnO₃·(1?x )LiNi_a Co_b Mn_c O₂ (a + b + c = 1) suffer a voltage fade upon cycling that limits their utilization in commercial batteries despite their extremely high discharge capacity, ≈250 mA h g^?1. Li‐rich, 0.35Li₂MnO₃·0.65LiNi_0.35Mn_0.45Co_0.20O₂, is exposed to NH₃ at 400 °C, producing materials with improved characteristics: enhanced electrode capacity and a limited average voltage fade during 100 cycles in half cells versus Li. Three main changes caused by NH₃ treatment are established. First, a general bulk reduction of Co and Mn is observed via X‐ray photoelectron spectroscopy and X‐ray absorption near edge structure. Next, a structural rearrangement lowers the coordination number of Co? O and Mn? O bonds, as well as formation of a surface spinel‐like structure. Additionally, Li⁺ removal from the bulk causes the formation of surface LiOH, Li₂CO₃, and Li₂O. These structural and surface changes can enhance the voltage and capacity stability of the Li‐rich material electrodes after moderate NH₃ treatment times of 1–2 h.