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Sulfur can be deposited on porous platinum black gas diffusion cathodes to influence the course of the electrogenerative reduction of nitric oxide. Polarization (performance) curves and reactor selectivity data are compared for untreated cathodes and thos

Porous Pt nanostructure decorated sulfur microparticles (Pt@S) are fabricated using sulfur as the template. The Pt@S electrode shows a higher volumetric specific capacity of 520 mA h cm-3 and improved cyclability with only 15% capacity fading a

A recently discovered series of quaternary compounds of the general type [Km(ROH)n][MxSnySez] (R = H, Me), containing ternary anions with [SnSe4]4-- coordinated transition metal centers (M = Co, Mn, Zn, Cd, Hg) has now been extended by the synthesis and characterization of the two ortho-thiostannate- coordinated species, [Na10(H2O)32][M 5Sn(μ3-S)4(SnS4) 4]·2H2O (M = Zn (1), Co (2)). The central structural motifs of compounds 1 and 2 are highly charged [M5Sn(μ 3-S)4(SnS4)4]10- anions, being the first T3-type supertetrahedral ternary anions reported to date. The exposure of single crystals of 2 to a dynamic vacuum for several hours resulted in the reversible formation of a partially dehydrated, but still monocrystalline material of the composition [Na10(H2O) 6][Co5Sn(μ3-S)4-(SnS 4)4] (3). The loss of 28 of the 34 water molecules only slightly affects the internal structure of the ternary anion in 3 and leads to a significant compacting of the crystal structure with closer linkage of the [Co5Sn5S20]10- cluster units via the Na+ cations. Magnetic measurements on 3 show that the ground state of the Co/Sn/S cluster is S = 1/2, indicating a significant antiferromagnetic coupling between the Co centers, which has also been rationalized by DFT investigations of the electronic situation in the ternary subunits of 1-3.

Kinetics of recovery of metals from the wastes and poor ores, which contain oxide and sulfide minerals of copper, vanadium, and silver with an azomethine solution in organic solvent was studied. The optimal parameters of the recovery were suggested.

The electrocatalytic activity of selenium-, and sulfur-modified polycrystalline Pt electrodes for O2 reduction in acid media has been examined using rotating ring-disk electrode techniques. The results obtained indicated that, within a rather narrow range of coverages, both Se-, and S-modified Pt surfaces promote O2 reduction via a two-electron pathway to yield hydrogen peroxide at close to 100% faradaic efficiency over a wide potential region. Also presented in this work is an experimental procedure for Se-modification of high area, unsupported Pt particles based on fluidized packed bed reactor principles. Such a strategy could be readily scaled up opening new prospects for the development of large scale hydrogen peroxide generation in acid media, including electrochemically based, room temperature, Nafion-based oxygen concentrators.

The disappearance rate of S2, which was produced from the pyrolysis of COS, was measured behind incident shock waves by monitoring the UV emission in the temperature range of 4500-6000 K and in the pressure range of 0.32-0.5 atm.It was found that two proc

Adsorption of hydrogen sulfide, sulfur dioxide, and their mixtures on four different catalysts has been studied by infrared spectroscopy of the catalyst surfaces. The four catalysts, which show a wide range of acidity and are all active for the Claus reaction (2H2S + SO2 → 3S + 2H2O), were γ-alumina (the main constituent of commercial bauxite catalysts), γ-alumina doped with NaOH, sodium Y zeolite, and hydrogen Y zeolite. All catalysts showed physical adsorption of both reactants with strong hydrogen bonding to surface OH groups. This would suggest that the role of the catalyst is primarily to bring the reactants together in suitable orientation. On the other hand, γ-alumina shows, on heating with SO2, a chemisorbed SO2 species which may be a reaction intermediate. The NaOH-treated γ-alumina shows a second chemisorbed SO2 species which is irreversibly adsorbed and thus may be a catalyst poison.

The paper deals with the properties of a new 4H-SnS2 phase (N-phase) synthesized together with berndtite 4H-SnS2 by a mechanochemical route from elemental tin and sulphur. The surface and bulk properties of SnS2 phases were verified by surface area measurements, particle size analysis, electron microscopy, XRD, M?ssbauer spectroscopy and chemical dissolution methods. The particles of synthesized product are 12-18 nm in size and during milling, secondary particles (aggregates) are formed that are 20-60 μm in size. The particle size and a high developed surface area (7-21 m2 g-1) greatly influence the solid-liquid reaction and solid transformations of mechanosynthesized tin sulphide products.

A novel simple process for preparing MoS2 by a mechanochemical route under the normal temperature and pressure has been developed. In this method, the mechanochemical solid-state reaction was completed in a high-energy planetary ball mill filled with pure argon. The effects of milling time and speed were discussed and the product was characterized by XRD, DSC and TEM. It is found that the as-obtained samples are MoS2 with short low stacked layers less than 10 nm, which have potential application in the highly active catalysts. Crown Copyright

A sulfur-coated carbon nanofiber (CNF-S) composite cathode material was prepared by a chemical deposition method in an aqueous solution. This CNF-S material was evaluated as the cathode material in lithium/sulfur cells with three different binders. The results of the SEM and TGA measurements reveal that CNF-S has a typical core-shell structure, containing 75.7 w/o sulfur coated uniformly on the surface of the CNFs. The effects of different binders on the potential profiles, electrode capacity and capacity retention with cycling were investigated. The electrode prepared with CMC + SBR binder has the best performance compared with PVdF and PEO binders, exhibiting a specific capacity of up to 1313 mAh g-1 S at the initial discharge and a specific capacity of 586 mAh g-1 S after 60 cycles.

Single-photon excitation spectra from the lowest singlet D 21 level of sulfur atoms were recorded with a tunable vacuum ultraviolet (VUV) radiation source generated by frequency tripling in noble gases. The photolysis of CS2 at 193 nm was used to produce the singlet S (D 21) sulfur atoms that were then excited to neutral superexcited states with the tunable VUV radiation. These superexcited states undergo autoionization into the first ionization continuum state of S+ (S 32 o4) + e-, which is not directly accessible from the S (D 21) state via an allowed transition. The excitation spectra were recorded by monitoring the S+ signal in a velocity imaging apparatus while scanning the VUV excitation wavelength. Three new lines were observed in the spectra which have not been previously reported. The full widths at half maximum (FWHM) of each of the observed transitions were determined by fitting the profiles of each absorption resonances with the Fano formula. Autoionization lifetimes τ of these singlet superexcited states were obtained from FWHM using the Uncertainty Principle. Abnormal autoionization lifetimes were found for the 3 s2 3 p3 (D o2) nd (D 21) and the 3 s2 3 p3 (D o2) ns (D 21) Rydberg series, in which τ (5d) and τ (7s) are shorter than τ (4d) and τ (6s), respectively. This is contrary to the well-known scaling law of τ (n*) ∝ n*3, which should be followed within a series unless there exist perturbations from other series or new channels open up to which some members of the series can decay. Possible perturbations from the nearby triplet series are suspected for causing the broadening of the 5d and 7s levels.

Experiments on liquid-phase oxidation of H2S with oxygen in the presence of catalysts, cobalt phthalocyanine sulfonates [CoPc(SO 3Na)n], were performed on a laboratory static installation in order to find conditions under which a stationary oxidation mode can be established at pH ≥ 8. The influence exerted by additional introduction of a soluble salt of Mn2+ (MnSO4, MnCl2) into the reaction mixture at various pH values was studied.

A new method is described that combines a tunable coherent vacuum ultraviolet (VUV) radiation source and an ion velocity imaging apparatus to study the autoionization of superexcited sulfur atoms. The photolysis of CS 2 at 193 nm is used to produce metastable sulfur atoms in the 1D2 state. The S(1D2) atom is then directly excited to the neutral superexcited state 3s23p 3(2D°)4d (1D2°) at 11.317 eV with a tunable VUV photon at ～121.896 nm. This excited state then undergoes autoionization into the first ionization continuum state of S+( 4S3/2°) + e-, which is not directly accessible from the S(1D2) state through optical transition. By monitoring the S+ signal in the time-of-flight mass spectrometer while scanning the excitation wavelength, the line profile of the 3s23p34d 1D2° ← 3s 23p4 1D2 transition is recorded and found to have a full width at half maximum (FWHM) of 0.9 cm-1. This has been used to determine an autoionization lifetime of the neutral superexcited 3s 23p34d 1D2° state of 5.9 ps. The accurate measurement of the autoionization lifetime provides a benchmark for testing fundamental theoretical models of processes occurring in excited states of atoms.

Lanthanum oxide by itself has been reported to be inactive for the reduction of SO2 by CO; however, we discovered that La2O3 can be activated in a reaction gas atmosphere if previously hydrated. The active phase of the activated lanthanum oxide was identified to be lanthanum oxysulfide by using X-ray diffraction. This showed that the activation was in essence a sulfidization of the oxide. An activation mechanism is proposed based on the surface acidic and basic properties resulting from the dehydroxylation of the lanthanum hydroxide.

Mixtures of alumina and iron powder provide efficient catalysts for the interaction of low concentrations of SO//2 with CO. The catalytic reaction rate at 500 C depended significantly on the iron content of the binary catalyst mixture. Mixtures containing 43% freshly reduced iron exhibited a sharp peak in the catalytic activity at 500 C when compared with other catalyst compositions. The normalized reaction rate per gram of iron, instead of per gram of total catalyst, still portrayed a sharp maximum when plotted against the weight fraction of iron in the catalyst.

Unsupported molybdenum disulfide catalysts with unique morphological pore structure were synthesized from tetraalkyammonium thiometalates precursors by in situ activation during the hydrodesulfurization (HDS) of dibenzothiophene. The precursors used in this study are ammonium thiomolybdate (ATM), tetrapropylammonium thiomolybdate, tetrapentylammonium thiomolybdate, tetrahexylammonium thiomolybdate, tetraheptylammonium thiomolybdate (THepATM), and tetraoctylammonium thiomolybdate. The thermogravimetrical analysis carried out under nitrogen demonstrated that all precursors yield MoS2 bulk structure at 623 K, after one or two decomposition steps. The morphology of these catalysts observed by scanning electron microscopy presents large hemispherical or ovoid cavities with a cheese-like porous arrangement, high surface area (from 255 up to 329 m2/g), high content of carbon (C/Mo = 2.7-4.0), and type IV adsorption-desorption isotherms of nitrogen. The nature of the alkyl group affects the surface area, the pore size distribution, and the HDS selectivity. The highest selectivity for direct C-S bond cleavage is observed for the molybdenum disulfide catalyst formed from THepATM. X-ray diffraction studies showed that the catalysts are poorly crystallized, with a very weak intensity of the (002) line of 2H-MoS2 characteristic of exfoliated samples.

Electrochemical techniques, complemented by weight change and ex situ X-ray spectroscopic measurements, were employed to characterize the corrosion of nickel in concentrated H2SO4 solutions. By use of a rotating cylinder electrode, it was found that corrosion is a mass-transport controlled process with the convective diffusion of nickel cations from a saturated NiSO4 layer as its rate-determining step. The oxidizing nature of the acid solution leads to the formation of additional corrosion products including metastable NiS, and elemental sulfur along with NiSO4, none of which is protective. When present on the surface, NiS establishes a galvanic interaction with the uncovered metal, significantly polarizing the anodic metal dissolution reaction. Since corrosion is mass-transport controlled, the resultant corrosion rate of the metal is unaffected during the galvanic-induced polarization.

Pb5S2I6 whiskers and tubules were synthesized from the reaction among lead chloride, thiourea, and excess sodium iodide under hydrothermal conditions at 200 °C for 20-40 h. XRD, SEM, XPS, ICP-AES, and TEM characterized the final products. Most products are whiskers with structure of 3-4 mm in length, 0.5-2.0 μm in diameter for a singular one. Meanwhile, about 10% tubules are produced in the process. The tubules are 3-6 mm in length, 8-20 μm in diameter, and 1-3 μm in thickness. Nanowhiskers were also produced in the route at 180-200 °C for 8-10 h. Raman spectra show that the Pb5S2I6 crystals have complex vibrational modes of PbS and PbI2.

The behavior of zinc sulfide in the system HNO3-Fe(NO 3)3-H2O at 25, 55, and 80°C was studied using the simplex-lattice design method.

Excitation functions for the title reactions were determined from 0.6 to 6 kcal/mol. Contrary to the analogous reaction of O(1D), it appears that the reaction of S(1D) proceeds solely through insertion over this energy range. Compared to other reactions, an intriguing H/D isotope effect was revealed. The propensity of the intramolecular H/D branching found under thermal conditions for A + HD reactions appears to be reverse for a supersonically cooled HD reagent. This finding implies that the reagent rotation could have profound influences on radical reactivity not only for an activated abstraction reaction, but for a barrierless inserted one.

An in situ sulfur deposition route has been developed for synthesizing sulfur-carbon composites as cathode materials for lithium-sulfur batteries. This facile synthesis method involves the precipitation of elemental sulfur at the interspaces between carbon nanoparticles in aqueous solution at room temperature. The product has been characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, charge-discharge measurements, and electrochemical impedance spectroscopy. The sulfur-carbon composite cathode with 75 wt.% active material thus obtained exhibits a remarkably high first discharge capacity of 1116 mAh g-1 with good cycle performance, maintaining 777 mAh g-1 after 50 cycles. The significantly improved electrochemical performance of the sulfur-carbon composite cathode is attributed to the carbon-wrapped sulfur network structure, which suppresses the loss of active material during charging/discharging and the migration of the polysulfide ions to the anode (i.e., shuttling effect). The integrity of the cathode structure during cycling is reflected in low impedance values observed after cycling. This facile in situ sulfur deposition route represents a low-cost approach to obtain high-performance sulfur-carbon composite cathodes for rechargeable Li-S batteries.

This work is part of our studies on the reactivity and crystal engineering of (1-diaminomethylene)thiourea (HATU). Structure and other properties of the selected products of the interaction of HATU with transition metal halides, also in the presence of 3%

The heat capacity of CuS has been measured by adiabatic shield calorimetry from 5 to 840 K.The heat capacity increases regularly up to about 750 K and then more strongly as the decomposition temperature (780.5 K) of covellite into high-digenite and sulfur is approached.The molar enthalpy and molar entropy of decomposition are 2149.3R*K and 2.755R.Above 780.5 K the uptake of sulfur in the high-digenite causes a further rise in the heat capacity.The low-temperature values increase more strongly than expected from the Debye relation with a Debye temperature estimated from the intermediate-temperature behavior.This phenomenon as well as a small bump in the heat capacity around 55 K are discussed.The resulting molar enthalpy and molar entropy at 298.15 and 825 K are 1136.6R*K, 8.101R, and 6744.2R*K, 17.393R, respectively.

The kinetics of the electrochemical deposition and desorption of sulfur monolayers on highly oriented Au(111) and polycrystalline Au electrodes in aqueous solutions containing sodium sulfide was studied by cyclic voltammetry, chronocoulometry, and chronoamperometry. Cyclic voltammetry experiments reveal that underpotential deposition (upd) and stripping of sulfur takes place at two different potentials at polycrystalline Au substrates leading to two oxidative and two reductive peaks. However, sulfur upd consists of only one oxidative and reductive peak at single crystalline Au(111) substrates. Electrosorption valancy measurements and pH dependency showed that the upd of sulfur involved two-electron and one-step mechanism. The charge corresponding to one monolayer of sulfur was determined by cyclic voltammetry and chronocoulometry, indicating a 0.33 coverage. The chronoamperometric results at polycrystalline Au electrodes indicates that deposition takes place in a Langmuir-type mechanism, whereas the stripping of sulfur follows a two-dimensional nucleation and growth mechanism which is accompanied by Langmuir adsorption. Although the appearance of current transients, observed for the deposition of sulfur on Au(111), was similar to what seen for deposition on polycrystalline Au substrates, the stripping process was totally different from deposition, involving only a two-dimensional nucleation and growth mechanism, at pH 12. From an analysis of the desorption current transient, we describe the stripping mechanism as instantaneous. Chronoamperometry experiments suggest that sulfur is first adsorbed on to a Au(111) surface randomly, then reorganizes itself to form a well-ordered structure, and finally strips off in a two-dimensional nucleation and growth mechanism.

Several synthetic and naturally occuring metal sulphides react with the system dimethyl sulphoxide-sulphur dioxide to give metal hydrogen sulphates or sulphates, in contrast with the reaction of sulphides with aqueous sulphur dioxide, which yields mainly thiosulphate.

Based on the comparison of reactant conversions in pulses on the stationary surface of the catalyst, the Claus reaction is found to occur via a stepwise mechanism. The nature of interaction of the SO2 and H2S molecules with the catalyst surface was studied by FTIR and UV-VIS spectroscopy and the reactivity of the adsorbed species was studied in situ. The intermediate adsorbed reactant species are determined. A scheme of the reaction mechanism over the Sn-Mo oxide catalyst is discussed.

Several thermal and photochemical reactions of sulfhydryl raducals, either in their monomeric (S radical/HS radical) or dimeric (H2S2(1-) radical) form, have been studied by using the pulse radiolysis technique.The dimer form is shown to react with O2 and methylviologen (MV(2+)).The tautomer reacts with O2 to produce a transient addition product, SO2(1-) radical, which further proceeds to give superoxide radicals.The dimer reacts slower with O2 by elecron transfer.The reaction of S(1-) radical/SH radical with MV(2+) yields several addition products which strongly absorb at λmax = 485 nm.These are partially converted to MV(1+) radical, either through a unimolecular process or by reaction with another MV(2+) molecule.Implications of these observation for the photocorrosion of semiconductor colloidal sulfides are discussed.In particular, the possibility of reduction processes by surface-adsorbed sulfydryl radicals, produced by hole trapping at the colloid surface, is considered.

The complex, K2.5Na2NH4[Mo2O2S 2(cit)2]-5H2O (1), was obtained by crystallization from a solution of (NH4)2MoS4, potassium citrate (K3cit) and hydroxyl sodium in methanol and water under an atmosphere of pure nitrogen at ambient temperature. The crystals are triclinic, space group PI, a = 7.376 (3)A, b = 14.620 (2) A, c = 14.661 (1) A, a = 71.10 (1)°, β= 81.77 (1)°, γ = 78.27(2)°, R = 0.0584 for 2545 observed (I > 2σ (I)) reflections. Single crystal structure analysis reveals that citrate ligand coordinated to molybdenum atom through two carboxylato oxygens and one deprotonated hydroxyl oxygen together with two bridging sulfur atoms and a terminal oxygen atom completes distorted coordination octahedron around each molybdenum atom. Principal dimensions are Mo = O1, 1.707 A (av); Mo-Sb, 2.341 A (av); Mo-O(hydrcoxyl), 2.021 A (av); Mo-O(α-carbaxyl), 2.1290 A (av) and Mo-O(β-carbaxyl), 2.268(av) A. IR spectrum is in agreement with the structure. Elsevier,.

Sequential two-photon photoexcitation of SO2 at 248 nm is found to lead to a number of primary fragments including S(3P) and SO(X 3Σ-).Further excitation of some of these photoproducts was also observed, occurring by both linear and two-quantum mechanisms.The resulting molecular X3P 3S vacuum ultraviolet emission from S atoms were detected and an analysis of the energy flow patterns was made.

We have determined the optimum geometry of the S-passivated InP(100)-(1x1) surface by dynamical low-energy electron-diffraction analysis. S atoms bond to In by occupying the bridge site that continues the zinc-blendestacking sequence of the substrate. Oth

A calorimetric method for determining the enthalpy of the aqueous oxidation of sulfide minerals at high temperatures and oxygen pressures has been developed and evaluated under conditions relevant to industrial pressure oxidation operations. This informat

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H2S selective catalytic oxidation technology is a prospective way for the treatment of low concentration acid gas with simple process operation and low investment. However, undesirable results such as large formation of SO2 and catalyst deactivation inevitably occur, due to the temperature rise of fixed reaction bed caused by the exothermic reaction. Catalyst with high activity in wide operating temperature window, especially in high temperature range, is urgently needed. In this paper, a series of copper-substituted hexaaluminate catalysts (LaCux, x = 0, 0.5, 1, 1.5, 2, 2.5) were prepared and investigated for the H2S selective oxidation reaction at high temperature conditions (300-550°C). The LaCu1 catalyst exhibited excellent catalytic performance and great stability, which was attributed to the best reductive properties and proper pore structure. Besides, two facile deep processing paths were proposed to eliminate the remaining H2S and SO2 in the tail gas.

Modulation of A-site defects is crucial to the redox reactions on ABO3 perovskites for both clean air application and electrochemical energy storage. Herein we report a scalable one-pot strategy for in situ regulation of La vacancies (VLa) in LaMnO3.15 by simply introducing urea in the traditional citrate process, and further reveal the fundamental relationship between VLa creation and surface lattice oxygen (Olatt) activation. The underlying mechanism is shortened Mn?O bonds, decreased orbital ordering, promoted MnO6 bending vibration and weakened Jahn–Teller distortion, ultimately realizing enhanced Mn-3d and O-2p orbital hybridization. The LaMnO3.15 with optimized VLa exhibits order of magnitude increase in toluene oxidation and ca. 0.05 V versus RHE (reversible hydrogen electrode) increase of half-wave potential in oxygen reduction reaction (ORR). The reported strategy can benefit the development of novel defect-meditated perovskites in both heterocatalysis and electrocatalysis.

Nanosheets incorporated with biological reducing agents are widely used to minimize the toxic effects of chemicals. Biologically amalgamated metal oxide nanomaterials have crucial importance in nanotechnology. In this study, bare and bismuth (Bi)-doped molybdenum disulfide (MoS2) nanosheets were synthesized via a hydrothermal method. Different Bi weight ratios of 2.5, 5, 7.5 and 10% were incorporated in a fixed amount of MoS2 to evaluate its catalytic and antimicrobial activities. Doped nanosheets were characterized using XRD, FTIR and UV-vis spectroscopy, FESEM, HRTEM, Raman, PL, DSC/TGA, EDX, XRF and XPS analysis. The XRD spectra confirmed that the doped nanosheets exhibit a hexagonal structure and their crystallite size increases gradually upon doping. The morphology and interlayer d-spacing of doped MoS2 were determined by FESEM and HRTEM. The presence of functional groups in the doped nanosheets was confirmed using FTIR, PL and Raman analysis. The absorption intensity increased and the corresponding measured band gap energy decreased with doping. The thermal stability and weight loss behaviour of the prepared samples were studied using DSC/TGA. The doped MoS2 nanosheets showed a higher catalytic potential compared to undoped MoS2. The doped Bi nanosheets exhibited higher antimicrobial activity against Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli) at different concentrations of Bi (0.075 and 0.1), showing a tendency to counter the emerging drug resistance against pathogenic bacterial diseases. Consequently, significant inhibition zones were recorded against (MDR) S. aureus ranging from 2.25 to 3.3 mm and 3.25 to 5.05 mm at low and high concentrations of doped-Bi nanosheets and against Gram-negative E. coli ranging from 1 to 1.45 mm at high concentrations. In conclusion, the Bi-doped MoS2 nanocomposite has exhibited significant potential for use in industrial dye degradation applications. Its antibacterial properties can also mitigate health risks associated with the presence of several well-known pathogens in the environment.

Splitting of hydrogen sulfide is achieved to produce value-added chemicals. Upon irradiation at 254 nm in the gas phase and in the absence of catalysts or photocatalysts at near room temperature, H2S splits into stoichiometric amounts of H2 and S with a quantum efficiency close to 50 %. No influence of the presence of CH4 and CO2 (typical components in natural gas and biogas in which H2S is an unwanted component) on the efficiency of overall H2S splitting was observed. A mechanism for the H2 and S formation is proposed.

All over the world researchers in accelerating to development the new and modern methods of desulfurization process to overcome the presence of residual sulfur compounds in the crude oil, which has harmful effects and undesirable. Out of these important r

5-Chloro-1,2,3,4-thiatriazole has been investigated in the gas phase for the first time by mid-infrared and He I photoelectron spectroscopy. The ground-state geometry has been obtained from quantum chemical calculations at the CCSD(T) and B3LYP levels using aug-cc-pVTZ basis set. Ionization potentials have been determined and the electronic structure has been discussed within the frame of molecular orbital theory. IR and photoelectron spectroscopies, supported by quantum chemical calculations at the B3LYP and SAC-CI levels, provide a detailed investigation into the vibrational and electronic character of the molecule. Thermal stability of 5-chloro-1,2,3,4-thiatriazole has been studied both experimentally and theoretically. Flash vacuum thermolysis of the molecule produces fast quantitatively N2, ClCN, and sulfur. Theoretical calculations at the CCSD(T)//B3LYP level predict competitive decomposition routes, starting either with a retro-cycloaddition reaction leading to N2S and ClCN or with a ring opening to chlorothiocarbonyl azide intermediate, to produce finally N2, S, and ClCN. Calculations also predict that N2S is reactive and decomposes in bimolecular reactions to N2 and S2.

A new strategy is reported for the synthesis of supported metal sulfides with high dispersion by sulfidation in dielectric barrier discharge (DBD) plasma under ambient conditions. According to the characterization data obtained by XRD, BET, UV-vis, TEM, XPS, ICP, and elemental analysis, the DBD plasma method not only reduces the preparation time but also achieves an increased dispersion, small particle size and uniform distribution compared to the traditional thermal method. These results prove that the plasma preparation method is a facile and flexible approach for the synthesis of metal sulfides. The plasma-prepared CdS/Al2O3 and ZnS/Al2O 3 catalysts exhibited high performances for hydrogen production from H2S with reduced energy costs. The enhancement might be attributable to the smaller particle size, higher surface area and dispersion, which enhances the semiconductor catalytic efficiency. the Partner Organisations 2014.

A model of photolysis of PbS2O3 aqueous solutions has been proposed on the basis of identified photolysis products and semiempirical quantum-chemical calculations. The degradation of PbS2O3 starts with the dissociation of the sulfur-sulfur bond in the thiosulfate group via photochemical excitation and transition of the system a whole to the activated state, which is decomposed by the solvent. The interaction of the primary photolysis products with PbS2O3 results in the formation of final products.

The crosstalk between two biologically important signaling molecules, nitric oxide (NO) and hydrogen sulfide (H2S), proceeds via elusive mechanism(s). Herein we report the formation of H2S by the action of NO on synthetic [2Fe-2S] clusters when the reaction environment is capable of providing a formal H? (e-/H+). Nitrosylation of (NEt4)2[Fe2S 2(SPh)4] (1) in the presence of PhSH or tBu3PhOH results in the formation of (NEt 4)[Fe(NO)2(SPh)2] (2) and H2S with the concomitant generation of PhSSPh or tBu3PhO ?. The amount of H2S generated is dependent on the electronic environment of the [2Fe-2S] cluster as well as the type of H ? donor. Employment of clusters with electron-donating groups or H? donors from thiols leads to a larger amount of H 2S evolution. The 1/NO reaction in the presence of PhSH exhibits biphasic decay kinetics with no deuterium kinetic isotope effect upon PhSD substitution. However, the rates of decay increase significantly with the use of 4-MeO-PhSH or 4-Me-PhSH in place of PhSH. These results provide the first chemical evidence to suggest that [Fe-S] clusters are likely to be a site for the crosstalk between NO and H2S in biology.

The electrochemical reduction of N,N′-dithiobisphthalimide and N,N′-thiobisphthalimide is investigated using electrochemical techniques and theoretical calculations. The results are rationalized using adequate electron transfer theories. The reduction leads to the ejection of diatomic sulfur and involves an interesting autocatalytic mechanism. This mechanism is dependent on the concentration of the initial compound and the cyclic voltammetric scan rate. The starting material is reduced both at the electrode and through homogeneous electron transfer from the produced sulfur. The initial electron transfer follows a stepwise mechanism involving the formation of the corresponding radical anion. This is supported by both the electrochemical data and the theoretical calculation results. The radical anion of the N,N′-dithiobisphthalimide dissociates through cleavage of the N-S chemical bond and not the S-S chemical bond. Application of the extension of the dissociative electron transfer theory to the dissociation of radical anions shows that the N-S chemical bond dissociates despite being stronger than the S-S chemical bond. This is due to the large difference in the oxidation potentials of the two potential anions (the phthalimidyl anion and the phthalimidyl thiyl anion). The electrochemical reduction of N,N′-thiobisphthalimide involves the intermediate formation of N,N′-dithiobisphthalimide and hence the autocatalytic process is less efficient.

Dimethyl sulfoxide is used as an oxidizing agent to oxidize hydrogen sulfide to solid sulfur at room temperatures and normal pressures, in which, β-cyelodextrin plays an important role in this reaction. in this work, when GC-MS, SEM and FTIR spectroscopic

Single crystal silicon nanoparticles (Si-NPs) of 20 nm were produced via laser pyrolysis with a virtually complete conversion from SiH4 to Si-NPs. SF6 was used as the photosensitizer to transfer laser beam energy to silicon precursor

We present new chalcogenide compounds, Ag2Te(MS 2)3 (M = V, Nb), built up of alternating planes of [MS2] and [Ag2Te]. The Ag and Te atoms are linearly coordinated by S atoms in the [MS2] layers and held in place by covalent interactions. Structural polymorphism was found by single crystal X-ray diffraction studies, where long-range ordering or disorder of the Ag and Te atoms within the hexagonal planar [Ag2Te] layer yielded two distinct crystal forms. When the Ag and Te atoms are ordered, the two isostructural compounds crystallize in the non-centrosymmetric P6I...2m space group, with a = 5.5347(8) A, c = 8.0248(16) A, and V = 212.89(6) A3 for α-Ag2Te(VS2)3 and a = 5.7195(8) A, c = 8.2230(16) A, and V = 232.96(6) A3 for α-Ag2Te(NbS2)3. For the occupationally disordered Ag/Te arrangement, a subcell of the ordered phase that crystallizes in the non-centrosymmetric P6I...m2 space group, with a = 3.2956(6) A (=aa/(3)1/2), c = 8.220(2) A, and V = 77.31(3) A3 for β-Ag 2Te(VS2)3, was identified. Furthermore, pair distribution function analysis revealed local distortions in the [Ag 2Te] layer. Band structure calculations at the density functional theory level were carried out to investigate the electronic structure of Ag 2Te(MS2)3. Electronic transport measurements on Ag2Te(MS2)3 show that they exhibit p-type metallic behavior. Thermal analyses and temperature-dependent powder X-ray diffraction studies were focused on the stability and transformation/ decomposition of the Ag2Te(MS2)3 phases. Magnetic susceptibility data are also reported. The new intercalated Ag 2Te(MS2)3 system features a unique hypervalent Te with a three-center, four-electron bonding environment isoelectronic to that found in I3-.

The aldol condensation reaction over sulfated zirconia led to the production of diacetone alcohol, which was further dehydrated forming mesityl oxide. The sulfated zirconia was obtained from zirconium acetate ethane sulfonate as a single source precursor. Oxides were obtained by calcinations of the precursors at 550-650 C, while the self-condensation reaction of acetone was carried out at 150 C. The precursor and the produced oxides were characterized using various characterization techniques. The precursors were synthesized with different acetate to ethane sulfonate ratio, ranging from 1 to 3. The major products obtained from the condensation reaction over the resulted oxide were mesityl oxide, mesitylene isophorone, naphthalene, and pentamers. The selectivity of mesityl oxide was approximately 100 % at the initial time-on-stream.

Technetium disulfide was prepared by reaction between the elements in a sealed tube at 450 °C, by reaction between Tc2(O 2CCH3)5 and H2S gas in a flowing system at 450 °C and by reaction between K2TcCl6 and H2S gas in sulfuric acid. The samples were analysed by X-ray absorption fine structure (XAFS) spectroscopy. The Royal Society of Chemistry 2013.

Oxo-sulfido- and oxo-selenido-molybdenum(vi) complexes with an ene-1,2-dithiolate ligand are generated as models of the active sites of molybdenum hydroxylases. The sulfide and selenide groups are highly reactive toward triphenylphosphine in the order of Se > S.

The gas phase ion chemistry of sulfuryl fluoride is studied by ion trap mass spectrometry and ab initio calculations. Reactions of ions of atmospheric relevance with neutral SO2F2 mainly result in SO 2F2 depletion by dissociative electron transfer. In few cases, a different reaction mechanism involving F-abstraction is invoked, since dissociative ion products are observed despite the electron transfer channel being endothermic. Ab initio calculations revealed a nearly perfect distonic structure for the molecular SO2F2+ ion, whose capability of activating strong HX bonds (X = C, N, O) is ascribable to the high spin density located on the oxygen atoms, in line with literature reports. Among the ions produced by electron ionization of SO2F2, the FSOx+ (x = 0-2) ions are capable of activating the HNH2 bond of ammonia. Theoretical investigation revealed that NH 3 activation by SF+ requires a triplet to singlet conversion along the reaction pathway. This conversion is expected to be fast, the conceivable reaction rate determining step being the subsequent intramolecular hydrogen migration.

A reaction-based colorimetric and ratiometric fluorescent probe based on an ICT-strategy for selective detection of H2S that exploited the H2S-mediated reduction of nitrocompound to amines was explored. And it displayed high selectivity for H2S over other relevant reactive sulfur, oxygen, nitrogen species and other anions with more than 120 nm blue shift and the change of emission intensity ratio inducted by H2S was over 4750.

Catalytic reduction of sulfur dioxide with converted gas obtained by various methods of conversion of natural gas was studied to select the most active reducing agent for SO2. Pleiades Publishing, Ltd., 2012.

Now they are 10! The title compound displays a new type of crystal structure and is labeled clathrate X according to the general classification of clathrate structures. In contrast to typical clathrates, this compound has three-coordinate atoms within the framework and combines distorted 24-vertex polyhedra (see picture, green) centered around tellurium guest atoms with very irregular 10-vertex polyhedra around sulfur atoms (yellow). (Figure Presented).

The Bi2S3 nanomaterials with various morphologies such as nanorods, nanowires, nanowire bundles, urchin-like microspheres and urchin-like microspheres with cavities have been successfully synthesized through a simple hydrothermal method. Experimental results indicate that sulfur sources play crucial roles in determining the morphologies of Bi 2S3 products. Moreover, formation mechanisms of different Bi2S3 nanostructures are discussed based on understanding of the growth habit of Bi2S3 crystal. Finally, we also studied the morphologies-dependent electrochemical and optical properties of the as-synthesized Bi2S3 nanomaterials. The Royal Society of Chemistry 2011.

A new series of heavy metal complexes are prepared. Sn(II), Sb(III), Pb(II) and Bi(III) are the metal ions used in complexation with two thiosemicarbazide ligands. The IR and 1H NMR spectra of the free ligands display their presence in thiole-thione forms coincide with each other. The IR spectra of the complexes support the presence of 2:2 molar ratio (M:HL) with HL1 ligand and 1:1 beside 1:2 with HL2. The ligand coordinates as bi molecules in some complexes and displays two tautomer forms at the same complex molecule 1H NMR spectra of Sn(II) and Sb(III) complexes were done and comes coincide with IR data. The electronic spectral analysis displays a lower shift appearance in n → π* charge transfer band in most isolated complexes. As well as, a new band is shinned in visible region with Sb(III), Bi(III) complexes and Sn(II)-HL2. This band is pointed to its use in spectrophotometric analysis for these metal ions. The TG analysis for all isolated compounds was briefly discussed. The molecular modeling parameters support the stability of thiole form of the free ligands in comparing with their thiones by a small difference. The antibacterial and antifungal activities were studied against some organisms and reveal the priority of most investigated complexes.

Metal phthalocyanine (MPc, M = Mn2+, Fe2+, Co2+, Ni2+ and Cu2+), metal tetrapyridinoporphyrazine, and metal tetrapyrazinoporphyrazine are synthesized by microwave reaction and characterized by elemental analyzer, IR spectroscopy and UV-vis spectroscopy. The catalytic activity of MPc derivatives to Li/SOCl2 battery is evaluated by the relative discharge energy of the battery whose electrolyte contains the compounds. The discharge energy of Li/SOCl2 battery catalyzed by MPc is approximately 0-61% higher than that of Li/SOCl2 battery in the absence of compounds, depending on the central metal ion. To the same central metal ion, the discharge energy of Li/SOCl2 battery catalyzed by MTAP is approximately 60% higher than that by MPc. The discharge energy of Li/SOCl2 battery in which SOCl2 contains MPTpz is approximately 17-19% higher than that of the battery in the absence of compounds, and almost independent of central metal ions. It shows a correlation existing between the structure and the catalytic active sites of MPc derivatives. The double active site model is proposed to interpret the results.

Conditions for the synthesis of the water-soluble lead thiosulfate complex Na6[Pb(S2O3)4] · 6H2O were determined. The complex synthesized was characterized by UV and IR spectroscopy and X-ray phase and thermal a

Three supramolecular coordination polymers (SCPs) [(AgSCN)2L] {L = 4,4′-bipyridine (bpy) (1), trans-1,2-bis(4-pyridyl)ethylene (tbpe) (2) and phenazine (phenz) (3)} have been synthesized and structurally characterized by single-crystal X-ray di

Thermal behaviour of sodium oxo-salts of sulphur: Na2SO 4, Na2S2O7, Na2S 2O6, Na2SO3, Na2S 2O5, Na2S

The bromine-tetrathionate reaction has been studied in the presence of phosphoric acid/dihydrogen phosphate buffer at T = 25 ± 0.1°C and at I = 0.5 M ionic strength with both stopped-flow technique and a conventional diode array spectrophotometer. The sto

Well-crystallized Rh2S3 and Rh17S 15 powders with average particle size of 100nm were solvothermally prepared at 673 K for 10 h with S/Rh ratio of 1.65 and 0.9, respectively. The crystallinity and phase of the r

The conversion of H2S into H2 and S (H2S → H2 + S) is beneficial from both environmental and energy standpoints. Here we report that H2S can be splitted stoichiometrically into hydrogen and sulfur on CdS-based photocatalysts under visible light irradiation using ethanolamine as a H2S solvent and reaction media at room temperature. Raman spectra showed that the produced sulfur existed as S2-4 and S2-6 after photocatalytic reaction. The hydroxyls of the reaction media were found to be crucial for the hydrogen production, and the rate-determining step (RDS) of photocatalytic splitting H2S in diethanolamine is discussed. Electrochemical evaluation showed that the potential of H2S splitting in ethanolamine was greatly lowered and the photogenerated electrons could be fully used to reduce protons for hydrogen production. A free-radical-related one-electron electrochemical oxidation process on platinum electrode is suggested. This work demonstrates the possibility of the direct splitting H2S into S and H2 via photocatalysis.

The photoionization efficiency (PIE) spectra of metastable sulfur (S) atoms in the D1 and S1 states have been recorded in the 73 350-84 950 cm-1frequency range by using a velocity-mapped ion imaging apparatus that u ses a tunable vacuum ultraviolet laser as the ionization source. The S (D1) and S (S1) atoms are produced by the 193 nm photodissociation of C S2. The observed PIE spectra of S (D1) and S (S1) shows 35 autoionizing resonances with little or no contribution from direct photoionization into the S+ (S 32 4) + e- ionization continuum. Velocity-mapped ion images of the S+ at the individual autoionizing Rydberg resonances are used to distinguish whether the lower state of the resonance originates from theD1, S1, or P3 states. The analysis and assignment of the Rydberg peaks revealed 22 new Rydberg states that were not previously known. The autoi onization lifetimes τ of the Rydberg states are derived from the linewidths by fitting the lines with the Fano formula. Deviations from the scaling law of τ (n* ) n*3, where n * is the effective quantum number of the Rydberg state, are observed. This observation is ascribed to perturbations by nearby triplet Rydberg states, which shorten the autoionization lifetimes of the singlet Rydberglevels.

We found new synthetic routes to obtain 1-D quaternary thiophosphate compounds and a 0-D molecular complex containing a Nb2S4 core from a 2-D ternary thiophosphate, Nb4P2S21. When Nb4P2S21 was reactedwith alkali metal halides (ACl; A=Na, K, Rb, Cs) or TlCl at 500-700 &de g;C, the -S-S-S- bridges in 2-D Nb2PS10-S-S10PNb2 were excised to form a 1-D chain, and cations wereinserted between the chains to form ANb2PS10 (A=N a, K, Rb, Cs, Tl). We also found that thallium chloride (TlCl) is an excellent reagent for further excision, and it substitutes chloride ligandsfor the sulfur ligands of 2-D Nb4P2S21 to form the molecular complex Tl5[Nb2S4Cl8]Cl. Crystal data for TlNb2PS10: monoclinic, Pn, a=6.9452(11) ?, b=7.3761(12) ?, 12.873(2) ?, β=104.472(3)°, and Z=2. Crystal data for Tl5[Nb2S4Cl8]Cl: orthorhombic, Immm, a=7.001(5) ?, b=9.509(7) ?, c=15.546(11) ?, and Z=2.

Behavior of silver sulfide in the system Ag2S-Fe(NO 3)3-HNO3-H2O was studied at 25, 55, and 80°C using the method of the simplex-lattice experiment design. The quantitative dependences of Ag2/su

High heating rate thermo-microscopic analysis, analytical atomic-emission technique with inductively coupled plasma and differential dissolution method have been used to investigate solid-liquid and solid-liquid-vapor transitions of refractory chalcogenides La2S3, MoS2, Mo2S3 and LiInSe2. The techniques were effective in determining the total pressure and vapor phase composition over the compounds in large temperature and pressure ranges. As a result, for compounds that evaporate incongruently, the melting points corresponding to their strict stoichiometry, the decomposition pressure-temperature relations, and other new results of the T-x phase diagrams for the La3S4-La2S3, Mo-MoS2, and Li2Se-LiInSe2 systems were obtained.

The dissociation of OCS has been investigated subsequent to excitation at 248 nm. Speed distributions, speed dependent translational anisotropy parameters, angular momentum alignment, and orientation are reported forthe channel leading to S (D21). In agreement with previous experiments, two product speed regimes have been identified, correlating with differ ing degrees of rotational excitation in the CO coproducts. The velocity dependence of the translational anisotropy is also shown to be in agreement with previous work. However, contrary to previous interpretations, the speed dependence is shown to primarily reflect the effects of nonaxial recoil and to be consistent with predominant excitation to the 2 A′1 electronic state. It is proposed that the associated electronic transition moment is polarized in the molecular plane, at an angle greater than ～60° to the initial linear OCS axis. The atomic angular momentum polarization data are interpreted in terms of a simple long-range interaction model to help identify likely surfaces populated during dissociation. Although the model neglects coherence between surfaces, the polarization data are shown to be consistent with the proposed dissociation mechanisms for the two product speed regimes. Large values for the lowand high rank in-plane orientation parameters are reported. These are b elieved to be the first example of a polyatomic system where these effects are found to be of the same order of magnitude as the angular momentum alignment.

The dissociation of OCS has been investigated subsequent to excitation at 248 nm using velocity map ion imaging. Speed distributions, speed dependent translational anisotropy parameters, and the atomic angular momentum orientation and alignment are reported for the channel leading to S (PJ3). The speed distributions and Β parameters are in broad agreement with previous work and show behavior that is highly sensitive to the S-atom spin-orbit state. The data are shown to be consistent with the operation of at least two triplet production mechanisms. Interpretation ofthe angular momentum polarization data in terms of an adiabatic picture has been used to help identify a likely dissociation pathway for the ma jority of the S (PJ3) products, which strongly favors production of J=2 fragment atoms, correlated, it is proposed, with rotationally hot and vibrationally cold CO cofragments. For these fragments, optical excitationto the 2 A′1 surface is thought to constitute the first step, as for the singlet dissociation channel. This is followed by crossing, via a conical intersection, to the ground 1 A′1 state, from where inte rsystem crossing occurs, populating the 1 A′3 1 A″3 (Π3) states. The proposed mechanism provides a qualitative rationale for the observed spin-orbit populations, as well as the S (PJ3) quantum yield and angular momentum polarization. At least one other production mechanism, leading to a more statistical S-atom spin-orbit state distribution androtationally cold, vibrationally hot CO cofragments, is thought to invo lve direct excitation to either the -3 or Π3 states.

The adsorption and reactivity of SO2 on the Ir(1 1 1) and Rh(1 1 1) surfaces were studied by surface science techniques. X-ray photoelectron spectroscopy measurements showed that SO2 was molecularly adsorbed on both the Ir(1 1 1) sur

The decomposition of NO and the reduction of NO by CO on La2O2S were studied using temperature-programmed reaction technique coupled with fast mass spectrometry, powder X-ray diffraction and X-ray photoelectron spectroscopy. The role of SO2 plays in the reduction is explored. It is found that the decomposition of NO is a favorable reaction step for the reduction of NO by CO achieved through a sulfur-assisted path. The oxygen produced in the decomposition is removed by the sulfur in the oxysulfide as SO2, which in turn is reduced back to sulfur by CO on La2O2S. An external supply of sulfur, such as SO2, in the feed is needed to maintain the population of sulfur in the oxysulfide and thus make the reduction sustainable.

The partial photoionization cross sections and asymmetry parameters of Satoms have been measured using constant-ionic-state (CIS) spectroscopy in the photon energy range 10.0-30.0 eV. The ionizations investigated in these CIS experiments are the (3p) -1 ionizations S +( 4 S)←S( 3 P), S + ( 2 D)←S( 3 P), and S + ( 2 P)←S( 3 P). For the first time Rydberg series which converge to the fourth ionization limit have been observed and assignments of these series have been proposed. These correspond to excitations to Rydberg states that areparts of series which converge to the fourth ionization limit, S +( 4 P)← S( 3 P) (3s) -1 , and autoionize to the lower S + ( 4 S), S + ( 2 D), or S + ( 2 P) states. For each series observed in the CIS spectra photoelectron angular distribution studies, combined with other evidence, has allowed the angular momentum character of thefree electron on autoionization to be determined.

We report the synthesis of a thermally stable, highly loaded (15 wt.%) Cu/Ce bimetallic mesoporous silica with high surface area and metal dispersion, which was the first template assisted mesoporous network successfully tested for the simultaneous reduction of SO2 and NO with CO, achieving complete conversion of the reactants to elemental sulfur and N2 at high space velocity 32 000 h-1. The Royal Society of Chemistry 2006.

A novel metal-oxide photocatalyst, ZnBiVO4, was investigated for the photodecomposition of hydrogen sulfide. ZnBiVO4 was prepared using the solid-state method, as well as a solution route for the first time. Oxides of zinc, bismuth, and vanadium were used for the solid-state method, whereas the respective metal salts were used as precursors for the solution route synthesis. The microstructure of the newly prepared ZnBiVO4 was examined using XRD and FESEM. Tetragonal and monoclinic crystallite systems were observed in this ternary oxide system. Nanocrystalline ZnBiVO4 was obtained through the solution route. The catalyst was also characterized using UV-visible diffuse reflectance spectroscopy to evaluate its band gap. Photodecomposition of H2S using this catalyst was observed for the first time. The influence of preparation methods on the photocatalytic activity of ZnBiVO4 was examined and it was observed that the ZnBiVO 4 prepared by the solution route led to a higher photocatalytic activity during H2S decomposition. It is noteworthy that the hydrogen evolution was enhanced by 100% using ZnBiVO4 prepared by the solution route as compared with the ZnBiVO4 prepared by the solid-state method.

The dynamics of the S(1D) + CD4 → SD + CD 3 reaction has been studied in a photolysis-probe experiment. S( 1D) reagent was prepared by laser photolysis of CS2, and the SD(X2Π) product was detected by laser fluorescence excitation. The nascent rotational/fine-structure state distribution of the SD(X 2Π) product was determined. The experimentally determined rotational state distribution within each fine-structure manifold agrees well with the predictions of a statistical 'prior' distribution, while the F 1 to F2 fine-structure branching ratio is higher than predicted statistically. The product state distribution is consistent with reaction through the formation and decay of an energized CD3SD complex.

The normal incidence X-ray standing wave (NIXSW) technique, supported by X-ray photoelectron spectroscopy and near-edge X-ray absorption fine structure (NEXAFS), has been used to determine the local adsorption geometry of SO 2 and SO3 on Ni(1 1 1). Chemical-state specific NIXSW data for coadsorbed SO3 and S, formed by the disproportionation of adsorbed SO2 after heating from 140 K to 270 K, were obtained using S 1s photoemission detection. For adsorbed SO2 at 140 K the new results confirm those of an earlier study [Jackson et al., Surf. Sci. 389 (1997) 223] that the molecule is located above hollow sites with its molecular plane parallel to the surface and the S and O atoms in off-atop sites; corrections to account for the non-dipole effects in the interpretation of the NIXSW monitored by S 1s and O 1s photoemission, not included in the earlier work, remove the need for any significant adsorption-induced distortion of the SO2 in this structure. SO3, not previously investigated, is found to occupy an off-bridge site with the C3v axis slightly tilted relative to the surface normal and with one O atom in an off-atop site and the other two O atoms roughly between bridge and hollow sites. The O atoms are approximately 0.87 ? closer to the surface than the S atom. This general bonding orientation for SO3 is similar to that found on Cu(1 1 1) and Cu(1 0 0) both experimentally and theoretically, although the detailed adsorption sites differ.