Sulfur Selenium Research Articles

Analysis and simulation of opto-electronics characterization of two-dimensional Janus monolayers for energy applications

First-principles simulations are conducted to investigate the absorption and optoelectronic efficacy of molybdenum–sulfur–selenium, referred to here as MoSSe, and molybdenum–sulfur–oxygen, referred to here as MoSO, Janus monolayers. The materials MoSSe and MoSO demonstrate characteristics of semiconductors, as they possess bandgaps of 2.00 eV (direct) and 1.61 eV (indirect), respectively. This property renders them highly suitable for efficient light absorption. The efficiency of absorption of the device was calculated for the MoSSe and MoSO families, leading to the observation that these material families demonstrate a broad absorption range spanning from the infrared to the ultraviolet regions of the electromagnetic spectrum. This finding represents a novel discovery. Furthermore, the design as a topmost cell is particularly attractive due to its exceptional device absorption efficiency and broader bandgap. This particular family ensures that its band edges remain in alignment with the water-redox potentials. Molybdenum sulfide and molybdenum selenide exhibit promising potential as photocatalysts and in optoelectronic device applications. This is attributed to their appealing photocatalytic properties and notable efficiency in absorbing light for the purpose of water splitting.

The Effect of Selenium-Based Ligands on Tungsten Acetylene Complexes.

Bioinspired tungsten acetylene complexes containing pyridine-2-selenolato (PySe) or 6-methyl-pyridine-2-selenolato (6-MePySe) ligands were synthesized. 77Se NMR spectroscopy allowed for an assessment of the resonance structures in the pyridine-2-selenolato ligands and the rationalization of chemoselectivity observed in regard to 1,2 migratory insertion of HC≡CH. [W(CO)(C2H2)(CHCH-PySe)(PySe)] is formed exclusively via insertion of HC≡CH into the W-N bond, while the use of bulkier 6-MePySe allows for the isolation of [W(CO)(C2H2)(6-MePySe)2], which only partially reacts with excess HC≡CH to give [W(CO)(C2H2)(CHCH-6-MePySe)(6-MePySe)]. Oxidation of [W(CO)(C2H2)(6-MePySe)2] with pyridine-N-oxide gave the tungsten(IV) complex [WO(C2H2)(6-MePySe)2]. Complexes [W(CO)(C2H2)(6-MePySe)2] and [WO(C2H2)(6-MePySe)2] react with trimethyl phosphine to carbyne complex [W(CO)(CCH2PMe3)(PMe3)2(6-MePySe)]Cl and alkylidene complex [WO(CHCHPMe3)(PMe3)2(6-MePySe)]Cl, respectively. The addition of substituted alkynes to [W(CO)3(PySe)2] via thermal decarbonylation gave complexes [W(CO)(MeC≡CMe)(PySe)2] and [W(CO)(HC≡Ct-Bu)(PySe)2], respectively. The here presented complexes are relevant for the modeling of the active site of acetylene hydratase from Pelobacter acetylenicus, in which a tungsten atom is enclosed in a sulfur-rich coordination sphere. A recently published theoretical study concluded that the exchange of sulfur for selenium would increase the activity of the enzyme. Our findings contrast this claim as comparative analysis concludes negligible structural and electronic differences between the selenium-based and previously published sulfur-based complexes.

Internal Electron Donor Accelerated Sulfur Redox for Aqueous Zn─S Batteries

AbstractImproving the electrical conductivity of sulfur cathode while ensuring its high affinity to catalyst holds the key to facilitate the reaction kinetics of aqueous zinc–sulfur batteries. Herein, the sulfur redox in aqueous electrolyte is accelerated by introducing selenium–sulfur bonds into the sulfur structure to build an internal electron transport path. The Se with less electronegativity can act as an electron donor to accelerate the binding between S and Zn2+. Meanwhile, the bonded Se in the electron‐poor state endows the modified sulfur cathode with a strong affinity to the I3− catalyst, which further facilitates the conversion efficiency. Thus, the internal electron donor assisted sulfur cathode delivers excellent electrochemical performance in terms of high reversible capacity (1490 mAh g−1 at 0.5 A g−1), competitive rate performance (1010 mAh g−1 at 4 A g−1), as well as outstanding cycle stability (735 mAh g−1 at 4 A g−1 after 500 cycles).

Biological and Catalytic Properties of Selenoproteins.

Selenocysteine is a catalytic residue at the active site of all selenoenzymes in bacteria and mammals, and it is incorporated into the polypeptide backbone by a co-translational process that relies on the recoding of a UGA termination codon into a serine/selenocysteine codon. The best-characterized selenoproteins from mammalian species and bacteria are discussed with emphasis on their biological function and catalytic mechanisms. A total of 25 genes coding for selenoproteins have been identified in the genome of mammals. Unlike the selenoenzymes of anaerobic bacteria, most mammalian selenoenzymes work as antioxidants and as redox regulators of cell metabolism and functions. Selenoprotein P contains several selenocysteine residues and serves as a selenocysteine reservoir for other selenoproteins in mammals. Although extensively studied, glutathione peroxidases are incompletely understood in terms of local and time-dependent distribution, and regulatory functions. Selenoenzymes take advantage of the nucleophilic reactivity of the selenolate form of selenocysteine. It is used with peroxides and their by-products such as disulfides and sulfoxides, but also with iodine in iodinated phenolic substrates. This results in the formation of Se-X bonds (X = O, S, N, or I) from which a selenenylsulfide intermediate is invariably produced. The initial selenolate group is then recycled by thiol addition. In bacterial glycine reductase and D-proline reductase, an unusual catalytic rupture of selenium-carbon bonds is observed. The exchange of selenium for sulfur in selenoproteins, and information obtained from model reactions, suggest that a generic advantage of selenium compared with sulfur relies on faster kinetics and better reversibility of its oxidation reactions.

Anion Defects Engineering of Ternary Nb-Based Chalcogenide Anodes Toward High-Performance Sodium-Based Dual-Ion Batteries

HighlightsWe developed an efficient and extensible strategy to produce the single-phase ternary NbSSe nanohybrids with defect-enrich microstructure.The anionic-Se doping play a key role in effectively modulating the electronic structure and surface chemistry of NbS2 phase, including the increased interlayers distance (0.65 nm), the enhanced intrinsic electrical conductivity (3.23 × 103 S m-1) and extra electroactive defect sites.The NbSSe/NC composite as anode exhibits rapid Na+ diffusion kinetics and increased capacitance behavior for Na+ storage, resulting in high reversible capacity and excellent cycling stability.Sodium-based dual-ion batteries (SDIBs) have gained tremendous attention due to their virtues of high operating voltage and low cost, yet it remains a tough challenge for the development of ideal anode material of SDIBs featuring with high kinetics and long durability. Herein, we report the design and fabrication of N-doped carbon film-modified niobium sulfur–selenium (NbSSe/NC) nanosheets architecture, which holds favorable merits for Na+ storage of enlarged interlayer space, improved electrical conductivity, as well as enhanced reaction reversibility, endowing it with high capacity, high-rate capability and high cycling stability. The combined electrochemical studies with density functional theory calculation reveal that the enriched defects in such nanosheets architecture can benefit for facilitating charge transfer and Na+ adsorption to speed the electrochemical kinetics. The NbSSe/NC composites are studied as the anode of a full SDIBs by pairing the expanded graphite as cathode, which shows an impressively cyclic durability with negligible capacity attenuation over 1000 cycles at 0.5 A g−1, as well as an outstanding energy density of 230.6 Wh kg−1 based on the total mass of anode and cathode.

Advancing Power Supply Devices for Electric Aircraft

The pollution caused by the construction of more aircraft that run on fuel will become more severe as more fuel-energy aircraft are built. As a result of the numerous environmental crises currently confronting the world, electric jumbo jets need to replace those that run on fuel. Note that the most interesting issue would be the airplane's power supplies. Research is conducted on the physical principles underpinning solar panels and power beaming. Batteries are an essential component of electric aircraft. The materials used to construct airplane batteries are among the most crucial aspects of battery design, and lithium-ion batteries are among the top options available. The capacity of the batteries will not decrease over time, and they will not catch fire or put passengers at risk. In order to maintain charging, a one-of-a-kind combination of sulfur and selenium is utilized. It has been discovered that solid sulfur selenium batteries have a good touch, do not ignite, are thinner (even thinner than lithium-ion batteries), and have a higher capacity for storing energy than lithium-ion batteries.

Selenium–sulfur functionalized biochar as amendment for mercury-contaminated soil: High effective immobilization and inhibition of mercury re-activation

The contamination of soils by mercury (Hg) seriously threatens the local ecological environment and public health. S-functionalized amendments are common remediation technology, yet, Hg re-activation often occurs in the commonly used immobilization remediation by S-functionalized amendments, resulting in an unsatisfactory remediation effect. In this study, a novel FeS–Se functionalized biochar composite (FeS-Se-BC) amendment was prepared and applied for the efficient remediation of Hg-polluted soil. An immobilization efficiency of 99.62% and 99.22% for H2O-extractable Hg and TCLP solution-extractable Hg was achieved with the application of FeS-Se-BC(0.05) after 180 d. The analyses of XPS, Hg-TPD, SEM-EDS demonstrated that excellent remediation performance by FeS-Se-BC resulted from the synergistic effect of FeS and Se to form HgS and HgSe concurrently. In comparison to the treatments of biochar and FeS-functionalized biochar (FeS-BC), FeS-Se-BC promoted the transformation of exchangeable, carbonate-bound, and Fe–Mn oxides-bound Hg fractions into organic material-bound, and residual fractions, effectively reducing the risk of Hg-contaminated soil from a highly dangerous level to a low risk. Furthermore, the introduction of Se clearly inhibited the re-activation of Hg and reduced the release of Hg by 81.12% compared to FeS-BC when the ratio of S2− to Hg was 5: 1 due to the formation of extremely stable HgSe. These results suggest that FeS-Se-BC has good potential for remediation of Hg-polluted soils which provides a new inhibitory idea for Hg re-activation after immobilization.

Postdeposition Sulfurization of CuInSe2 Solar Absorbers by Employing Sacrificial CuInS2 Precursor Layers

Herein, a new route of sulfur grading in CuInSe2 (CISe) thin‐film solar absorbers by introducing an ultrathin (<50 nm) sacrificial sputtered CuInS2 (CIS) layer on top of the CISe. Different CIS top layer compositions (Cu‐poor to Cu‐rich) are analyzed, before and after a high‐temperature treatment in selenium (Se)‐ or selenium+sulfur (SeS)‐rich atmospheres. An [S]/([S] + [Se]) grading from the surface into the bulk of the Se‐ and SeS‐treated samples is observed, and evidence of the formation of a mixed CuIn(S,Se)2 phase by Raman analysis and X‐ray diffraction is provided. The optical bandgap from quantum efficiency measurements of solar cells is increased from 1.00 eV for the CISe reference to 1.14 and 1.30 eV for the Se‐ and SeS‐treated bilayer samples, respectively. A ≈150 mV higher VOC is observed for the SeS‐treated bilayer sample, but the cell exhibits blocking characteristics resulting in lower efficiency as compared with the CISe reference. This blocking is attributed to an internal electron barrier at the interface to the sulfur‐rich surface layer. The difference in reaction routes and possible ways to improve the developed sulfurization process are discussed.

Visible Light-Mediated Selenium–Sulfur Bond Formation to Afford Selenium–Sulfur Bond-Containing Peptides

Key words photocatalysis - Se–S bond formation - diselenides - selenopeptides

Corrosion Resistance of Sulfur-Selenium Alloy Coatings.

Despite decades of research, metallic corrosion remains a long-standing challenge in many engineering applications. Specifically, designing a material that can resist corrosion both in abiotic as well as biotic environments remains elusive. Here a lightweight sulfur-selenium (S-Se) alloy is designed with high stiffness and ductility that can serve as an excellent corrosion-resistant coating with protection efficiency of ≈99.9% for steel in a wide range of diverse environments. S-Se coated mild steel shows a corrosion rate that is 6-7 orders of magnitude lower than bare metal in abiotic (simulated seawater and sodium sulfate solution) and biotic (sulfate-reducing bacterial medium) environments. The coating is strongly adhesive, mechanically robust, and demonstrates excellent damage/deformation recovery properties, which provide the added advantage of significantly reducing the probability of a defect being generated and sustained in the coating, thus improving its longevity. The high corrosion resistance of the alloy is attributed in diverse environments to its semicrystalline, nonporous, antimicrobial, and viscoelastic nature with superior mechanical performance, enabling it to successfully block a variety of diffusing species.

Spectroscopic Signatures of Interlayer Coupling in Janus MoSSe/MoS2 Heterostructures.

The interlayer coupling in van der Waals heterostructures governs a variety of optical and electronic properties. The intrinsic dipole moment of Janus transition metal dichalcogenides (TMDs) offers a simple and versatile approach to tune the interlayer interactions. In this work, we demonstrate how the van der Waals interlayer coupling and charge transfer of Janus MoSSe/MoS2 heterobilayers can be tuned by the twist angle and interface composition. Specifically, the Janus heterostructures with a sulfur/sulfur (S/S) interface display stronger interlayer coupling than the heterostructures with a selenium/sulfur (Se/S) interface as shown by the low-frequency Raman modes. The differences in interlayer interactions are explained by the interlayer distance computed by density-functional theory (DFT). More intriguingly, the built-in electric field contributed by the charge density redistribution and interlayer coupling also play important roles in the interfacial charge transfer. Namely, the S/S and Se/S interfaces exhibit different levels of photoluminescence (PL) quenching of MoS2 A exciton, suggesting enhanced and reduced charge transfer at the S/S and Se/S interface, respectively. Our work demonstrates how the asymmetry of Janus TMDs can be used to tailor the interfacial interactions in van der Waals heterostructures.

Synergistic Effect between S and Se Enhancing the Electrochemical Behavior of SexSy in Aqueous Zn Metal Batteries

AbstractDeveloping high‐capacity conversional cathode materials for aqueous Zn batteries is promising to improve their energy densities but challenging as well. In this work, three kinds of selenium–sulfur solid solutions and their composites (denoted as SeS14 @ 3D‐NPCF, SeS5.76 @ 3D‐NPCF, and SeS2.46 @ 3D‐NPCF) are proposed and systematically investigated. Due to the introduction of Se and its synergistic effect with S, their physical and electrochemical properties are manipulated; in particular, by optimizing the Se content in these composites, SeS5.76 @ 3D‐NPCF shows a capacity of 1222 mAh g−1 and flat plateau of 0.71 V at 0.2 A g−1, reaching an ultrahigh energy density of 867.6 Wh kg−1 (based on SeS5.76), superior rate capacity of 713 mAh g−1 at 5 A g−1, and stable cycling of 75% capacity retention after 500 cycles. In addition, the Zn storage kinetics is determined by the discharge process, during which SeS5.76 @ 3D‐NPCF is converted into ZnSe and ZnS. More importantly, theoretical calculations reveal that Se can tailor the electron density difference, band structure, and reaction energy of S, which increase its conductivity and reactivity to facilitate the electrochemical reaction with Zn. This work explores high performance conversional cathode materials for aqueous Zn metal batteries and presents an effective strategy to modify their intrinsic properties.

SYNTHESIS AND CHARACTERIZATION OF N-(4-ACETYLPHENYL)-N-(DIPHENYLPHOSPHINO)- P,P-DIPHENYLPHOSPHINOUS AMIDE DERIVATIVES: APPLICATION OF A Pd(ΙΙ) DERIVATIVE AS A PRE-CATALYST IN THE SUZUKI CROSS-COUPLING REACTION

The reaction of p-aminoacetophenone with two equivalents of chlorodiphenylphosphine yields the (p-CH3CO)C6H4N(PPh2)2 ligand (1) in a good yield. The oxidation of 1 with elemental sulfur or grey selenium gives the corresponding disulfide and diselenide bis(phosphanyl)amine ligands (p-CH3CO)C6H4N(P(E)Ph2)2 (E = S(2), Se(3)), respectively. Reactions of 1 with group-10B metals afford $$cis\text{-}M\text{C}{{\text{l}}_{\text{2}}}[\mathbf{1}-{}_{k}^{2}P,P]\ (M=\text{Pd}\,(\mathbf{4}),\ \text{Pt}\,(\mathbf{5})),$$ respectively. Compounds 1-5 are identified and characterized by multinuclear NMR spectroscopy (1H, 13C, 31P, 77Se NMR), IR spectroscopy, and the elemental analysis. Crystal structure determinations are carried out for 2 and 3. The application of the Pd(II) complex as a pre-catalyst in the Suzuki cross-coupling reaction is also investigated.

Effect of selenium–sulfur interaction on the anabolism of sulforaphane in broccoli

The effects of S (as sulphate) and Se (as selenite) treatment (S mM/Se μM: 1/0, 1/50, 1/100, 1/150, 4/0, 4/50, 4/100, and 4/150) on the production of sulforaphane (an anticancer compound), the accumulation of its precursor substance, and the expression of genes related to glucoraphanin biosynthesis in broccoli were examined. Sulforaphane yield and myrosinase activity increased significantly with the combined application of 4 mM S and 100 μM Se on broccoli. Furthermore, the concentrations of glucoraphanin (a sulforaphane precursor) and methionine (a glucoraphanin substrate) slightly changed after Se application. And the strong anticancer activity of compound Se–SMC was further improved. Analysis of related gene expression showed that MY, which encodes myrosinase, was strongly induced by Se treatment. Thus, the myrosinase activity induced by Se treatment is the dominant factor affecting sulforaphane yield from glucoraphanin hydrolyzation. Selenium–sulfur biofortification provides a technical support for the cultivation of broccoli with high sulforaphane and high anti-cancer selenium compounds.

Cover Feature: Symmetric Mixed Sulfur–Selenium Fused Ring Systems as Potential Materials for Organic Field‐Effect Transistors (Chem. Eur. J. 13/2020)

Cover Feature: Symmetric Mixed Sulfur–Selenium Fused Ring Systems as Potential Materials for Organic Field‐Effect Transistors (Chem. Eur. J. 13/2020)

Selenium Incorporation to Amino Acids in Chlorella Cultures Grown in Phototrophic and Heterotrophic Regimes.

Microalgae accumulate bioavailable selenium-containing amino acids (Se-AAs), and these are useful as a food supplement. While this accumulation has been studied in phototrophic algal cultures, little data exists for heterotrophic cultures. We have determined the Se-AAs content, selenium/sulfur (Se/S) substitution rates, and overall Se accumulation balance in photo- and heterotrophic Chlorella cultures. Laboratory trials revealed that heterotrophic cultures tolerate Se doses ∼8-fold higher compared to phototrophic cultures, resulting in a ∼2-3-fold higher Se-AAs content. In large-scale experiments, both cultivation regimes provided comparable Se-AAs content. Outdoor phototrophic cultures accumulated up to 400 μg g-1 of total Se-AAs and exhibited a high level of Se/S substitution (5-10%) with 30-60% organic/total Se embedded in the biomass. A slightly higher content of Se-AAs and ratio of Se/S substitution was obtained for a heterotrophic culture in pilot-scale fermentors. The data presented here shows that heterotrophic Chlorella cultures provide an alternative for Se-enriched biomass production and provides information on Se-AAs content and speciation in different cultivation regimes.

Synthesis and characterization of N-(4-acetylphenyl)-N-(diphenylphosphino)-P,P-diphenylphosphinous amide derivatives: application of a Pd(ΙΙ) derivative as a pre-catalyst in the Suzuki cross-coupling reaction

The reaction of p-aminoacetophenone with two equivalents of chlorodiphenylphosphine yields the (p-CH3CO)C6H4N(PPh2)2 ligand (1) in a good yield. The oxidation of 1 with elemental sulfur or grey selenium gives the corresponding disulfide and diselenide bis(phosphanyl)amine ligands (p-CH3CO)C6H4N(P(E)Ph2)2 [E = S(2), Se(3)], respectively. Reactions of 1 with group-10B metals afford cis-MCl2[1 – 2kP,P] (M = Pd (4), Pt (5)) respectively. Compounds 1—5 are identified and characterized by multinuclear NMR spectroscopy (1H, 13C, 31P, 77Se NMR), IR spectroscopy, and the elemental analysis. Crystal structure determinations are carried out for 2 and 3. The application of the Pd(II) complex as a pre-catalyst in the Suzuki cross-coupling reaction is also investigated.

Electron Microscopy of Sulfur Selenium Alloy with High –K Dielectric Properties.

Electron Microscopy of Sulfur Selenium Alloy with High –K Dielectric Properties.

Double-layered hollow carbon spheres embedded in 3D conductive network as an efficient Se0.4S0.6 host for advanced lithium batteries

Selenium–sulfur solid solutions show unique advantages beyond sulfur and selenium as cathode materials for lithium batteries. Herein, we propose a dual-confined SexSy-based cathode with a three-dimensional (3D) network structure where Se0.4S0.6 is first encapsulated in double-layered hollow carbon spheres (DLHCs) and embedded by 3D graphene-like material (3DG) shells. The dissolution of polysulfides/polyselenides in the cathode is effectively inhibited through dual confinement from DLHCs and 3DG as well as chemical binding between sulfur and selenium. Benefiting from the indispensable advantages of Se0.4S0.6 and the uniquely designed host architecture, the 3DG-DLHC-Se0.4S0.6 cathode delivers a high reversible capacity of 627 mAh g−1 at 0.2 A g−1 after 200 cycles, good rate capability of 533 mAh g−1 at 2 A g−1, and outstanding long cycling stability over 500 cycles with Coulombic efficiency almost reaching 100%.

Adopting Mixed Sulfur and Selenium Chalcogenides As High Energy Density Copolymer Cathodes in Rechargeable Sodium Metal Systems

The ever increasing demand for energy storage has encouraged exploration of battery systems with higher energy density and lower cost than Li-ion batteries.1 This work reveals the very first demonstration of a room temperature, sodium/polymeric mixed-chalcogenide battery. The chemistry is enabled by crosslinking of sulfur and selenium, which maintains the elemental mixture in long chains instead of crystalline rings, for a mechanistically different conversion cathode. Room temperature Li-S batteries, which boast ultra-high energy density (~2600 Wh/kg) and low cost/highly abundant sulfur, are expected to succeed the intercalation Li-ion battery (<400 Wh/kg), but to-date deliver impractical cycle life due to active material dissolution. The novel chain assembly provided by crosslinking prevents this behavior, enabling extensive cycle life.2 Herein the crosslinker type and molecular ratio are modulated for optimal chain length and performance. Furthermore, selenium delivers 20 orders of magnitude greater electrical conductivity than sulfur.3 The atomic ratio of sulfur to selenium is modulated for a balance of electrical conductivity and energy density. Notably, these cathodes are simplistically processed at temperatures below 200 ˚C. The crosslinked, mixed chalcogenide cathodes are paired with metallic sodium anodes, that are 3 orders of magnitude more abundant than lithium metal,1 and exhibit favorable plating behavior in the system-prescribed, ether-based electrolytes.4 This full cell touts a theoretical energy density of ~1000 Wh/kg and effective incorporation of highly abundant raw materials. Hong, X.; Mei, J.; Wen, L.; Tong, Y.; Vasileff, A. J.; Wang, L.; Liang, J.; Sun, Z.; Dou, S. X., Nonlithium Metal–Sulfur Batteries: Steps Toward a Leap. Advanced Materials 0 (0), 1802822.Simmonds, A. G.; Griebel, J. J.; Park, J.; Kim, K. R.; Chung, W. J.; Oleshko, V. P.; Kim, J.; Kim, E. T.; Glass, R. S.; Soles, C. L.; Sung, Y.-E.; Char, K.; Pyun, J., Inverse Vulcanization of Elemental Sulfur to Prepare Polymeric Electrode Materials for Li–S Batteries. ACS Macro Letters 2014, 3 (3), 229-232.Abouimrane, A.; Dambournet, D.; Chapman, K. W.; Chupas, P. J.; Weng, W.; Amine, K., A New Class of Lithium and Sodium Rechargeable Batteries Based on Selenium and Selenium–Sulfur as a Positive Electrode. Journal of the American Chemical Society 2012, 134 (10), 4505-4508.Seh, Z. W.; Sun, J.; Sun, Y.; Cui, Y., A Highly Reversible Room-Temperature Sodium Metal Anode. ACS Central Science 2015, 1 (8), 449-455.