Na2 SO4 Research Articles

Ion‐dependent metabolic responses of Vicia faba L. to salt stress

Salt-affected farmlands are increasingly burdened by chlorides, carbonates, and sulfates of sodium, calcium, and magnesium. Intriguingly, the underlying physiological processes are studied almost always under NaCl stress. Two faba bean cultivars were subjected to low- and high-salt treatments of NaCl, Na2 SO4 , and KCl. Assimilation rate and leaf water vapor conductance were reduced to approximately 25-30% without biomass reduction after 7days salt stress, but this did not cause severe carbon shortage. The equimolar treatments of Na+ , K+ , and Cl- showed comparable accumulation patterns in leaves and roots, except for SO4 2- which did not accumulate. To gain a detailed understanding of the effects caused by the tested ion combinations, we performed nontargeted gas chromatography-mass spectrometry-based metabolite profiling. Metabolic responses to various salts were in part highly linearly correlated, but only a few metabolite responses were common to all salts and in both cultivars. At high salt concentrations, only myo-inositol, allantoin, and glycerophosphoglycerol were highly significantly increased in roots under all tested conditions. We discovered several metabolic responses that were preferentially associated with the presence of Na+ , K+ , or Cl- . For example, increases of leaf proline and decreases of leaf fumaric acid and malic acid were apparently associated with Cl- accumulation.

Coating Polymeric Carbon Nitride Photoanodes on Conductive Y:ZnO Nanorod Arrays for Overall Water Splitting.

Polymeric carbon nitride (PCN) photosensitizers are proposed replacements for their inorganic counterparts in solar-to-fuel conversion via photoelectrochemical water splitting. However, intense charge recombination, primarily because of surface defects, limits the use of PCN in PEC systems. Now, photoanodes are designed by coating PCN films onto highly conductive yttrium-doped zinc oxide (Y:ZnO) nanorods (NRs) serving as charge collectors. The generation of charge carriers can therefore be promoted by this type II alignment. The charge collectors would be kept nearby for charge separation and transport to be used in the interfacial redox reactions. The photocurrent density of the polymer electrode is improved to 0.4 mA cm-2 at 1.23 V vs. the reversible hydrogen electrode in a Na2 SO4 electrolyte solution under AM 1.5 illumination. The result reveals a more than 50-fold enhancement over the PCN films achieved by powder; the efficiency can be preserved at 95 % for 160 minutes.

Flexible Fe2 O3 and V2 O5 Nanofibers as Binder-Free Electrodes for High-Performance All-Solid-State Asymmetric Supercapacitors.

Flexible, highly porous Fe2 O3 and V2 O5 nanofibers (NFs) have been synthesized by a facile electrospinning method followed by calcination. They have been directly used as binder-free electrodes for high-performance supercapacitors. These Fe2 O3 and V2 O5 NFs interconnect with one another and construct three-dimensional hierarchical porous films with high specific surface areas. Benefitting from their unique structural features, binder-free Fe2 O3 and V2 O5 porous nanofiber electrodes offer high specific capacitances of 255 F g-1 and 256 F g-1 , respectively, at 2 mV s-1 in 1 m aqueous Na2 SO4 as electrolyte. An all-solid-state asymmetric supercapacitor (ASC) has been fabricated using Fe2 O3 and V2 O5 nanofibers as negative and positive electrodes, respectively. It could be operated at up to 1.8 V, taking advantage of the wide and opposite potential windows of the respective electrodes. The assembled all-solid-state ASC achieved a high energy density up to 32.2 W h kg-1 at an average power density of 128.7 W kg-1 , and exhibited excellent cycling stability and power capability. The effective and facile synthesis method and superior electrochemical performance described herein make electrospun Fe2 O3 and V2 O5 NFs promising electrode materials for high-performance ASCs.

Electrochemical Ammonia Synthesis via Nitrogen Reduction Reaction on a MoS2 Catalyst: Theoretical and Experimental Studies.

The discovery of stable and noble-metal-free catalysts toward efficient electrochemical reduction of nitrogen (N2 ) to ammonia (NH3 ) is highly desired and significantly critical for the earth nitrogen cycle. Here, based on the theoretical predictions, MoS2 is first utilized to catalyze the N2 reduction reaction (NRR) under room temperature and atmospheric pressure. Electrochemical tests reveal that such catalyst achieves a high Faradaic efficiency (1.17%) and NH3 yield (8.08 × 10-11 mol s-1 cm-1 ) at -0.5 V versus reversible hydrogen electrode in 0.1 m Na2 SO4 . Even in acidic conditions, where strong hydrogen evolution reaction occurs, MoS2 is still active for the NRR. This work represents an important addition to the growing family of transition-metal-based catalysts with advanced performance in NRR.

Amine-Triggered Dopamine Polymerization: From Aqueous Solution to Organic Solvents.

Dopamine (DA) polymerization has received significant attention in many fields, however, almost all of the works are limited to aqueous solution and hamper its wide application. This paper reports that amines can trigger DA polymerization by capturing the H+ from DA hydrochloride and intermediates to accelerate the generation of radical species in water or organic solvents. Increasing concentration and decreasing pKb of amines cause the reaction equilibrium to shift toward the product polydopamine (PDA). Water-soluble and easily-removable Na2 SO4 nanowires and NaCl cubes can be used as templates to prepare different morphologies of hollow PDA structures by DA polymerization in ethanol solution. The carbonization production of PDA nanotubes at 900 °C (PDNC-900) is obtained and demonstrates electrochemical activity in the oxygen reduction reaction that is comparable to that of Pt/C.

Enhancing Capacity Performance by Utilizing the Redox Chemistry of the Electrolyte in a Dual-Electrolyte Sodium-Ion Battery.

A strategy is described to increase charge storage in a dual electrolyte Na-ion battery (DESIB) by combining the redox chemistry of the electrolyte with a Na+ ion de-insertion/insertion cathode. Conventional electrolytes do not contribute to charge storage in battery systems, but redox-active electrolytes augment this property via charge transfer reactions at the electrode-electrolyte interface. The capacity of the cathode combined with that provided by the electrolyte redox reaction thus increases overall charge storage. An aqueous sodium hexacyanoferrate (Na4 Fe(CN)6 ) solution is employed as the redox-active electrolyte (Na-FC) and sodium nickel Prussian blue (Nax -NiBP) as the Na+ ion insertion/de-insertion cathode. The capacity of DESIB with Na-FC electrolyte is twice that of a battery using a conventional (Na2 SO4 ) electrolyte. The use of redox-active electrolytes in batteries of any kind is an efficient and scalable approach to develop advanced high-energy-density storage systems.

Site-Selective Functionalization of Flagellin by Steric Self-Protection: A Strategy To Facilitate Flagellin as a Self-Adjuvanting Carrier in Conjugate Vaccine.

Flagellin (FliC) can act as a carrier protein in the preparation of conjugate vaccines to elicit a T-cell-dependent immune response and as an intrinsic adjuvant to activate the toll-like receptor 5 (TLR5) to enhance vaccine potency. To enable the use of FliC as a self-adjuvanting carrier, an effective method for site-selective modification (SSM) of pertinent amino-acid residues in the D2 and D3 domains of FliC is explored without excessive modification of the D0 and D1 domains, which are responsible for activating and binding with TLR5. In highly concentrated Na2 SO4 solution, FliC monomers form flagellar filaments, in which the D0 and D1 domains are situated inside the tubular structure. Thus, the lysine residues (K219, K224, K324, and K331) in the D2 and D3 domains of flagellin are selectively modified by a diazo-transfer reaction with imidazole-1-sulfonyl azide. The sites with azido modification are confirmed by MALDI-TOF-MS, ESI-TOF-MS, and LC-MS/MS analyses along with label-free quantitation. The azido-modified filament dissolves to give FliC monomers, which can conjugate with alkyne-hinged saccharides by the click reaction. Transmission electron microscopy imaging, dynamic light scattering measurements, and the secreted embryonic alkaline phosphatase reporter assay indicate that the modified FliC monomers retain the ability either to bind with TLR5 or to reassemble into filaments. Overall, this study establishes a feasible method for the SSM of FliC by steric self-protection of the D0 and D1 domains.

Influence of dilution water ionic composition on acute major ion toxicity to the mayfly Neocloeon triangulifer.

Field and laboratory studies have shown that mayflies (Ephemeroptera) tend to be relatively sensitive to elevated major ion concentrations, but little is known about how ionic composition influences these responses. The present study evaluated the acute toxicity of major ion salts to the mayfly Neocloeon triangulifer over a range of background water quality conditions. The mayfly was particularly sensitive to Na2 SO4 , with the median lethal concentration (LC50) of 1338 mg SO4 /L being lower than LC50s reported for 7 other species at that hardness. Increasing hardness of the dilution water from 30 to 150 mg/L (as CaCO3 ) resulted in doubling of LC50s for sodium salts, and an approximately 1.5-fold increase in LC50 for MgSO4 . Potassium salt toxicity was not strongly influenced by hardness, consistent with findings for other species. When hardness was held constant but the Ca to Mg ratio was manipulated, the ameliorative effect on Na2 SO4 and NaCl did not appear as strong as when hardness was varied; but for MgSO4 the amelioration relative to Ca activity was similar between the 2 experiments. The toxicity of K salts to N. triangulifer was similar to Na salts on a millimolar basis, which contrasts with several other species for which K salts have been much more toxic. In addition, the toxicity of KCl to N. triangulifer was not notably affected by Na concentration, as has been shown for Ceriodaphnia dubia. Finally, plotting LC50s in terms of ion activity (Cl, SO4 , Na, Mg, or K) over the range of Ca activities in dilution water resulted in significant positive relationships, with comparable slopes to those previously observed for C. dubia over the same range of Ca activities. Environ Toxicol Chem 2018;37:1330-1339. © 2018 SETAC.

Achieving Insertion-Like Capacity at Ultrahigh Rate via Tunable Surface Pseudocapacitance.

The insertion/deinsertion mechanism enables plenty of charge-storage sites in the bulk phase to be accessible to intercalated ions, giving rise to at least one more order of magnitude higher energy density than the adsorption/desorption mechanism. However, the sluggish ion diffusion in the bulk phase leads to several orders of magnitude slower charge-transport kinetics. An ideal energy-storage device should possess high power density and large energy density simultaneously. Herein, surface-modified Fe2 O3 quantum dots anchored on graphene nanosheets are developed and exhibit greatly enhanced pseudocapacitance via fast dual-ion-involved redox reactions with both large specific capacity and fast charge/discharge capability. By using an aqueous Na2 SO3 electrolyte, the oxygen-vacancy-tuned Fe2 O3 surface greatly enhances the absorption of SO32- anions that majorly increase the surface pseudocapacitance. Significantly, the Fe2 O3 -based electrode delivers a high specific capacity of 749 C g-1 at 5 mV s-1 and retains 290 C g-1 at an ultrahigh scan rate of 3.2 V s-1 . With a novel dual-electrolyte design, a 2 V Fe2 O3 /Na2 SO3 //MnO2 /Na2 SO4 asymmetric supercapacitor is constructed, delivering a high energy density of 75 W h kg-1 at a power density of 3125 W kg-1 .

In Situ Growth of MnO2 Nanosheets on N-Doped Carbon Nanotubes Derived from Polypyrrole Tubes for Supercapacitors.

Nitrogen-doped porous carbon nanotubes@MnO2 (N-CNTs@MnO2 ) nanocomposites are prepared through the in situ growth of MnO2 nanosheets on N-CNTs derived from polypyrrole nanotubes (PNTs). Benefiting from the synergistic effects between N-CNTs (high conductivity and N doping level) and MnO2 nanosheets (high theoretical capacity), the as-prepared N-CNTs@MnO2 -800 nanocomposites show a specific capacitance of 219 F g-1 at a current density of 1.0 A g-1 , which is higher than that of pure MnO2 nanosheets (128 F g-1 ) and PNTs (42 F g-1 ) in 0.5 m Na2 SO4 solution. Meanwhile, the capacitance retention of 86.8 % (after 1000 cycles at 10 A g-1 ) indicates an excellent electrochemical performance of N-CNTs@MnO2 prepared in this work.

Potato plants (Solanum tuberosum L.) are chloride-sensitive: Is this dogma valid?

Chloride sensitivity of the potato (Solanum tuberosum L.) cultivars Marabel and Désirée was investigated in two pot experiments (soil/sand mixture and hydroponics). It was tested whether there are differential effects of KCl and K2 SO4 application on tuber yield and tuber quality, and whether both potato cultivars differ in their chloride sensitivity. Tuber yield, dry matter percentage of the tubers, starch concentration and starch yield were not significantly affected by potassium source (K2 SO4 or KCl). After exposure to salt stress in hydroponics (100 mmol L-1 NaCl, 50 mmol L-1 Na2 SO4 , 50 mmol L-1 CaCl2 ) for 5 days, 3-week-old potato plants had significantly reduced shoot dry mass after NaCl and Na2 SO4 application. However, CaCl2 treatment did not significantly affect shoot growth, although the chloride concentration reached 65 to 74 mg Cl- mg-1 dry matter, similar to the NaCl treatment. In contrast, growth reductions were closely related to sodium concentrations, thus plants suffered sodium toxicity and not chloride toxicity. Both potato cultivars are chloride-resistant and can be fertilised with KCl instead of K2 SO4 without the risk of depression in tuber yield or tuber quality. The statement that potatoes are chloride-sensitive and that chloride has negative effects on yield performance needs reconsideration. © 2017 Society of Chemical Industry.

A simple and reliable method reducing sulfate to sulfide for multiple sulfur isotope analysis.

RationalePrecise analysis of four sulfur isotopes of sulfate in geological and environmental samples provides the means to extract unique information in wide geological contexts. Reduction of sulfate to sulfide is the first step to access such information. The conventional reduction method suffers from a cumbersome distillation system, long reaction time and large volume of the reducing solution. We present a new and simple method enabling the process of multiple samples at one time with a much reduced volume of reducing solution.MethodsOne mL of reducing solution made of HI and NaH2PO2 was added to a septum glass tube with dry sulfate. The tube was heated at 124°C and the produced H2S was purged with inert gas (He or N2) through gas‐washing tubes and then collected by NaOH solution. The collected H2S was converted into Ag2S by adding AgNO3 solution and the co‐precipitated Ag2O was removed by adding a few drops of concentrated HNO3.ResultsWithin 2–3 h, a 100% yield was observed for samples with 0.2–2.5 μmol Na2SO4. The reduction rate was much slower for BaSO4 and a complete reduction was not observed. International sulfur reference materials, NBS‐127, SO‐5 and SO‐6, were processed with this method, and the measured against accepted δ34S values yielded a linear regression line which had a slope of 0.99 ± 0.01 and a R 2 value of 0.998.ConclusionsThe new methodology is easy to handle and allows us to process multiple samples at a time. It has also demonstrated good reproducibility in terms of H2S yield and for further isotope analysis. It is thus a good alternative to the conventional manual method, especially when processing samples with limited amount of sulfate available.

The Design of a New Cobalt Sulfide Nanoparticle Implanted Porous Organic Polymer Nanohybrid as a Smart and Durable Water-Splitting Photoelectrocatalyst.

Development of an inexpensive, efficient and robust nanohybrid catalyst as a substitute for platinum in photoelectrocatalytic hydrogen production has been considered intriguing and challenging. In this study, the design and sequential synthesis of a novel cobalt sulfide nanoparticle grafted Porous Organic Polymer nanohybrid (CoSx @POP) is reported and used as an active and durable water-splitting photoelectrocatalyst in the hydrogen evolution reaction (HER). The specific textural and relevant chemical properties of as-synthesised nanohybrid materials (Co3 O4 @POP &CoSx @POP) were investigated by means of XRD, XPS, FTIR, 13 C CP MAS NMR, spectroscopy, HR-TEM, HAADF-STEM with the corresponding elemental mapping, FE-SEM and nitrogen physisorption studies. CoSx @POP has been evaluated as a superior photoelectrocatalyst in HER, achieving a current density of 6.43 mA cm-2 at 0 V versus the reversible hydrogen electrode (RHE) in a 0.5 m Na2 SO4 electrolyte which outperforms its Co3 O4 @POP analogue. It was found that the nanohybrid CoSx @POP catalyst exhibited a substantially enhanced catalytic performance of 1.07 μmol min-1 cm-2 , which is considered to be ca. 10 and 1.94 times higher than that of pristine POP and CoSx , respectively. Remarkable photoelectrocatalytic activity of CoSx @POP compared to Co3 O4 @POP toward H2 evolution could be attributed to intrinsic synergistic effect of CoSx and POP, leading to the formation of a unique CoSx @POP nanoarchitecture with high porosity, which permits easy diffusion of electrolyte and efficient electron transfer from POP to CoSx during hydrogen generation with a tunable bandgap, that straddles between the reduction and oxidation potential of water.

GEOLOGICAL AND GEOMECHANICAL PROPERTIES OF SOME CARBONATE MARBLES AND BASALT STONE FROM MOROCCO

The natural rocks used today as well as in the history for a variety of purposes were a subject of different alteration, weathering and deterioration conditions. These conditions are strictly controlled by environment and nature of rock varieties (marble and stone). This study is a first approach to understand the relation between some geological features and behavior against salt (Na 2SO4) decay of Moroccan marbles and stones. For this purpose, widely used four dolomitic limestones, two crystalline limestones, one limestone and one basalt sample (total 8) were chosen from Morocco. Extra attention paid to choose locations being a representative of all Moroccan country. The carbonate samples (limestone and dolomite) consist of mainly dolomite and calcite with micritic and sparitic cement. The sole, non-carbonaceous sample is basalt of Khenifra containing mainly plagioclase and pyroxene. In general, both bulk-dry and powder density values of the studied rock samples are homogeneous. The limestone of Bir Jdid has the highest (10.81 %) effective porosity and dry weight loss value (4.61 %). The loss on ignition value of the Khenifra basalt has the lowest value with 1.26 %. The loss on ignition values are also relatively uniform. The obtained data indicate that outdoor uses (especially in coastal areas) of limestones of Bir Jdid and dolomitic limestones of Taza are more risky than the others.

Replacing PAPS: In vitro phase II sulfation of steroids with the liver S9 fraction employing ATP and sodium sulfate.

In vitro technologies provide the capacity to study drug metabolism where in vivo studies are precluded due to ethical or financial constraints. The metabolites generated by in vitro studies can assist anti-doping laboratories to develop protocols for the detection of novel substances that would otherwise evade routine screening efforts. In addition, professional bodies such as the Association of Official Racing Chemists (AORC) currently permit the use of in-vitro-derived reference materials for confirmation purposes providing additional impetus for the development of cost effective in vitro metabolism platforms. In this work, alternative conditions for in vitro phase II sulfation using human, equine or canine liver S9 fraction were developed, with adenosine triphosphate (ATP) and sodium sulfate in place of the expensive and unstable co-factor 3'-phosphoadenosine-5'-phosphosulfate (PAPS), and employed for the generation of six representative steroidal sulfates. Using these conditions, the equine in vitro phase II metabolism of the synthetic or so-called designer steroid furazadrol ([1',2']isoxazolo[4',5':2,3]-5α-androstan-17β-ol) was investigated, with ATP and Na2 SO4 providing comparable metabolism to reactions using PAPS. The major in vitro metabolites of furazadrol matched those observed in a previously reported equine in vivo study. Finally, the equine in vitro phase II metabolism of the synthetic steroid superdrol (methasterone, 17β-hydroxy-2α,17α-dimethyl-5α-androstan-3-one) was performed as a prediction of the in vivo metabolic profile.

Energy Storage: A Dual-Function Na2 SO4 Template Directed Formation of Cathode Materials with a High Content of Sulfur Nanodots for Lithium-Sulfur Batteries (Small 27/2017)

Energy Storage: A Dual-Function Na₂ SO₄ Template Directed Formation of Cathode Materials with a High Content of Sulfur Nanodots for Lithium-Sulfur Batteries (Small 27/2017)

Construction of Er3+ :YAlO3 /RGO/TiO2 Hybrid Electrode with Enhanced Photoelectrocatalytic Performance in Methylene Blue Degradation Under Visible Light.

Much attention has been paid on doping TiO2 to narrow its band gap to promote the absorption of visible light and restrain the recombination of electron-hole pairs to improve its efficiency in photoelectrocatalysis (PEC) under visible-light irradiation. However, the oxidation potential energy of photo-induced holes for the modified catalysts by visible-light excitation is lower than that without modification by UV excitation. In this work, we synthesized a co-coupled TiO2 electrode (denoted ERT) with the Er3+ :YAlO3 and reduced graphene oxide (RGO), achieving the synergetic effect of visible-light-to-UV up-conversion and response and great electron transfer ability. The effects of external bias voltage, electrolyte concentration and pH on the PEC activity were studied with the methylene blue (MB) as the target pollutant. The results indicated that PEC by the ERT electrode showed the highest MB removal compared with those by the electrodes coupled with RGO or Er3+ :YAlO3 alone. In addition, the kinetic rate constant of the PEC process using the ERT electrode was higher than the sum of those of the photocatalytic and electrocatalytic processes. The optimal conditions for PEC by the ERT electrode were an external bias voltage of 1.0 V, 0.1 mol L-1 Na2 SO4 and pH = 10.

A Dual-Function Na2 SO4 Template Directed Formation of Cathode Materials with a High Content of Sulfur Nanodots for Lithium-Sulfur Batteries.

The sulfur content in carbon-sulfur hybrid using the melt-diffusion method is normally lower than 70 wt%, which greatly decreases the energy density of the cathode in lithium-sulfur (Li-S) batteries. Here, a scalable method inspired by the commercialized production of Na2 S is used to prepare a hierarchical porous carbon-sulfur hybrid (denoted HPC-S) with high sulfur content (≈85 wt%). The HPC-S is characterized by the structure of sulfur nanodots naturally embedded in a 3D carbon network. The strategy uses Na2 SO4 as the starting material, which serves not only as the sulfur precursor but also as a salt template for the formation of the 3D carbon network. The HPC-S cathode with such a high sulfur content shows excellent rate performance and cycling stability in Li-S batteries because of the sulfur nanoparticles, the unique carbon framework, and the strong interaction between them. The production method can also be readily scaled up and used in practical Li-S battery applications.

P Doped MoO3-x Nanosheets as Efficient and Stable Electrocatalysts for Hydrogen Evolution.

A P doped MoO3-x nanocomposite material with rich oxygen vacancies is successfully fabricated by a two-step intercalation method, which presents superior activity for the hydrogen evolution reaction with low overpotential and fast electron transfer. In 0.5 m H2 SO4 , it displays an overpotential of 166 mV for driving the current density of 10 mA cm-2 . Moreover, it also shows a good catalytic stability in the electrolytes with different pH, 0.5 m H2 SO4 (strong acid), 0.5 m Na2 SO4 (neutral solution), and 0.1 m NaOH (strong base). The superior catalytic activity and stability are due to to the synergistic effect between the P element doping and the oxygen vacancies.

Effect of Salt and Ethanol Addition on Zein-Starch Dough and Bread Quality.

Development of viscoelastic doughs from non-wheat proteins allows for a wider range of gluten-free products. Little work has been completed to describe mechanisms of zein functionality in food systems. To identify factors responsible for dough development in zein-starch mixtures and their influence on zein bread quality, a mixture of 20% zein-80% maize starch was mixed with water and various reagents. Salts, NaSCN, NaCl, and Na2 SO4 were evaluated at concentrations from 0 to 2M for their influence on the properties of zein-starch dough systems. NaSCN at low concentrations produced softer dough. Ethanol treatments produced softer more workable dough in the absence of salts. Increasing concentrations of NaCl and Na2 SO4 resulted in coalescing of the proteins and no dough formation. The addition of β-ME had minimal softening effects on zein-starch dough. Specific volumes of zein-starch bread increased with decreasing NaCl addition in bread formulations. Likewise, including 5% ethanol (v/v) in the bread formula increased bread quality.