Excess Sulfur Research Articles

Impact of Sulfur Deficiency and Excess on the Growth and Development of Soybean Seedlings.

Sulfur is a critical element for plant growth and development, serving as a component of amino acids (cysteine and methionine), iron-sulfur clusters, proteins, glutathione, coenzymes, and auxin precursors. Deficiency or low concentrations of sulfur in the soil can lead to significant growth retardation in plants. The objective of our study was to examine the effects of sulfur (S) deficiency and excess on morphological symptoms, sulfur and nitrogen (N) metabolism, as well as antioxidant activity in soybean. We found that S starvation decreased the fine root length, biomass, and activity, and the chlorophyll content was reduced, while excess sulfur promotes lateral root growth. In contrast to sulfur excess, sulfur deficiency inhibits N and S metabolism levels in both subsurface and above-ground parts, and induced the expression of some sulfur transporters (SULTRs). In this study, we created soybean hairy root lines overexpressing the SULTR gene (GmSULTR2;1a) to observe metabolic changes following sulfur deficiency treatment. The results showed that GmSULTR2;1a saved the sulfur-deficient phenotype, and the antioxidant enzyme activity was much higher than that of the wildtype in the absence of sulfur. Our study revealed the important role of sulfur element in soybean growth and development and the regulation of sulfur deficiency by GmSULTR2;1a.

An Acid-Activatable Fluorescent Probe for Sulfur Dioxide in Traditional Chinese Medicines and Living Cells.

Excessive sulfur dioxide (SO₂) disturbs physiology of lysosomes causing diseases and threatening human health. A fluorescent probe has been regarded as one of the most attractive approaches, which is compatible with living cells and possesses high sensitivity. However, most of fluorescent probes' reaction sites are activated before they reach the destination. In this work, an acid-activatable fluorescent probe PT1 was synthesized, characterized, and used for SO2 detection. The introduction of oxazolines in PT1 enables the intelligent response of probe to release the activation stie for SO2 derivatives through Michael addition upon exposure to acid. In vitro studies showed a remarkable selectivity of PT1 to SO₂ derivatives than other biothiols with a limit of detection as low as 62 nM. By using this acidic pH-controlled fluorescence responsiveness to SO₂, precise spatiotemporal identification of lysosomal SO2 fluctuations has been successfully performed. Furthermore, probe PT1 can be applied for monitoring SO₂ derivatives in traditional Chinese medicines.

Collapse of G+/G- bands, modification of Breit–Wigner–Fano signals and structural amorphization in single wall carbon nanotube networks under great excess of sulfur

The identification of superconductivity and ferromagnetic to superconductive transitions in sulfur-modified carbons has recently attracted an important attention. Additional work is however needed to better understand the structural modification of the graphitic interfaces in presence of sulfur. Here we report on an advanced methodology which involves soaking of large amounts (in the order of 500 mg) of sulfur through several annealing cycles into bundles comprising of hollow single-wall/few-wall carbon nanotubes (SWCNTs). TEM, HRTEM, XRD and Raman spectroscopy characterization analyses reveal the presence of structural amorphization of the SWCNTs, with dramatic impact on the intensity of the G+ and a progressive vanishing of the G- signal-contribution. We demonstrate the presence of high sulfur content by employing both point and mapping energy dispersive X-rays (EDX maps) acquisitions, with high local quantities of sulfur in the order of 16 %. Interestingly, a complex variation in the contribution of the Breit-Wigner-Fano (BWF) band, with appearance of extra D, G+ and C-S band-contributions, is revealed by deconvolution-analyses. The appearance of these structural features is a clear indicator of structural amorphization of the CNTs, with consequential formation of C-S hybrid structures, which we analyze systematically with the aid of energy dispersive X-ray spectrum mapping and Raman point/mapping spectroscopy approaches.

Investigations on optical properties of synthesized covellite CuS hollow nano cubic structures

In this work, hollow nanocubes of CuS were synthesized by employing a chemical route via Kirkendall effect. The influence of sulphur concentration on the optical and structural properties of CuS by varying the amount of sulphur during synthesis was investigated. The synthesized hollow cubes were characterized by using Scanning Electron microscope (SEM), X-Ray Diffraction (XRD) Analysis, Ultra Violet -Visible (UV-Vis.) Spectroscopy, Photoluminescence (PL) Spectroscopy, Raman Spectroscopy and X-ray photoelectron Spectroscopy (XPS). The formation of cubic morphology was affirmed by SEM analysis in all three samples. The length of the sidesthe of the cube lies in the range of 500-600 nm. XRD studies confirmed the formation of the pure phase of covellite CuS. Also, XPS analysis validated the presence of excess sulphur in the sample with Cu:S as 1:150 along with variation in the stoichiometric ratio of 1: 0.5. Since, this was not the case for Cu:S as 1:100, as it showed the desired stoichiometry of 1.1: 0.9 that supports the pure phase of CuS. Raman spectra further confirmed the purity of the sample. Absorption analysis revealed a well-defined bandgap with the absence of an intermediate defect state with a bandgap of 1.4 eV in the optimized sample. PL spectra displayed a decent recombination rate and minimum non-radiative losses in the 1:100 sample. These outcomes assurances the sample with Cu:S as 1:100 could be used as a potential material for solar cell applications.

Computationally Predicted New Solid-State Electrolyte (Li5+x PS4+x Cl2-x : 0 ≤ x ≤ 2) and Poly Sulfide Cathodes (Li3+y PS9 or Li5+y PS9Cl2: 0 ≤ y ≤ 9) for High Performance Li Metal Anode Batteries

We used Molecular Dynamics (MD) simulations to study the structures and conductivity of sulfide-based ceramics from the superionic conductor argyrodite family for applications as solid-state electrolyte and cathode materials. These studies combined quantum mechanics (QM) and ReaxFF reactive force field based MD, where the ReaxFF parameters were developed from QM MD.[1]Currently Li10GeP2S12 (LGPS) demonstrates one of the highest Li-ion conductivity for solid state electrolyte, 12 mS/cm at 300K, but it is highly reactive with the Li-metal anode, and it is expensive due to the presence of Ge. We studied the Li ion diffusion mechanism and ionic conductivity of the promising Li6(PS4)SCl solid state electrolyte, predicted to have a conductivity of s = 6 mS/cm, close to experiment (4 mS/cm). We find that Li migration in this electrolyte occurs via conjugated substitutional type diffusion involving rearrangements of three (or more) Li-ions and ~ 3 vacant sites in a 3D matrix of anions that are essentially stationary at 298K (over 20 ns of simulation). We carried out 10 ns of MD simulation to predict a Li-ion conductivity for a single phase Li6(PS4)SCl of 5.9 mS/cm in agreement with solid state NMR measurements of 3.9 mS/cm. Our calculated activation energy of 0.24 eV is within experimentally reported range.[2]We report here the computationally predicted structure of Li5PS4Cl2, a new sulfide Li-superionic conductor with the highest Li-ion conductivity at solid state, which we predict to have Li-ion conductivity of 20 mS/cm at 298 K. We also predicted the directional ionic conductivity and Li-migration barrier in it. This Li5PS4Cl2 has not yet been synthesized and studied experimentally.We also report our results on QM and ReaxFF MD for new polysulfide cathodes, Li3+y PS4+n and Li5+y PS4+nCl2 , both based on Li3PS4. Here, n is the number of excess sulfur atoms in the fully charged polysulfide cathode per formula unit with y=0 and y is the excess Li added to the cathode during discharge processes. We evaluated the performance of these cathode electrolyte systems in terms of interfacial stability and discharge voltages.Li3PS4+5 is a potential cathode for lithium-sulfur batteries. We predicted the structures of Li3PS4+5 finding extra S3 and S7 chains attached to one S atom of each PS4 group. This leads to a density of 2.2 g/cm3. As the cathode is discharged, the lithium atoms fill up all the gaps between S atoms, leading to Li3+9 PS4+5, with 1.7 g/cm3. We studied the dynamics of the discharge as lithium ions from the metal move into the material and react with the S-S bonds to make Li2S. Our predicted discharge curve agrees well with the experimental data (Figure 1).[3]We extended these studies to design a new polysulfide cathode Li5PS4+5Cl2 to be used with our newly predicted Li-superionic conductor electrolytes. The interfacial stability of the Solid electrolyte with S-based cathode and with Li-anode were studied (Figure 2).Our work presents a new strategy for designing materials and processes for solid-state batteries using computational screening and chemical substitution. This demonstrates the potential of using lithium PS4 based superionic conductors with PS4 based cathodes for applications in solid-state batteries. We also addresses some of the key challenges in accelerating solid-state battery development, such as phase stability, transport properties, electrode compatibility etc. This work demonstrates how computational studies can guide new avenues for experimental developments to advance of solid-state battery technology for applications ranging from grid storage to electric vehicles.Acknowledgements:We acknowledge the support from Hong Kong Quantum AI Lab, AIR@InnoHK of Hong Kong Government.

Advancing sustainability with inverse vulcanization of waste sulfur catalyzed with TiO2

There is a need for sustainable valorization solutions for the problem of excess sulfur arising from abundant natural sources of sulfur and the production of millions of tons of sulfur annually as a byproduct of refineries. Developing sulfur-based polymers with enhanced mechanical properties using the process of inverse vulcanization could be a valuable endeavor, since the poor mechanical properties of current sulfur polymers limit their scale-up and widespread application. Herein, we studied the performance of titanium oxide (TiO2) in improving the mechanical properties of the sulfur polymer through copolymerization with oleic acid. To study the efficacy of TiO2 and oleic acid in copolymerization with sulfur. we used laboratory experiments and a computational approach geared toward the use of the density functional theory (DFT). Based on the DFT results, the coordination of the third and fourth ligands (oleic acid chains) to the Ti4+ ion are not as strong as the coordination of the first two ligands mainly because of the high steric hindrance around the metal ion. The low values of binding energy for Ti2+–di oleate and Ti+–tri oleate make them more accessible to sulfur chains. This in turn, promotes the cross-linking reactions in a process of inverse vulcanization. This was further reflected in an increase of up to 637.3% in sulfur–oleic acid blends in presence of TiO2. This study contributes to the sustainable use of abundant sulfur and the sustainable development of the polymer industry.

Influence of atmospheric conditions on the formation and structural properties of two-dimensional SbSI films

Two-dimensional heavy pnictogen chalcohalides, such as SbSI, SbSeI, and BiSI, are promising materials for solar energy harvesting (SEH) devices. In this paper, we report the influence of atmospheric conditions on the formation and structural properties of SbSI films fabricated under N2 and air atmospheres using a modified two-step method. Under N2 atmosphere, a preferentially (121)-oriented SbSI film without impurities formed. In contrast, under air atmosphere, a film with mixed crystalline phases of SbSI and secondary Sb2O3 formed. The Sb2O3 phase could be reduced by applying excess sulfur. These results provide a fundamental step toward optimizing the properties of chalcohalides for SEH device applications.

Synthesis of copper sulfide (CuxS) films by one-step thermal reduction of copper formate–amine–sulfur complex pastes with low sulfur ratios

A one-step thermal-reduction method was used to synthesize copper sulfide (CuxS, x = 1–2) films using copper formate–sulfur–amine pastes with low sulfur ratios (sulfur/copper formate = 0.5–1.0). The synthesized films were mixtures of Cu + Cu2S, Cu2S + Cu1.8S, or Cu1.8S + CuS, depending on the sulfur ratio. Cu1.8S alone films were synthesized from the paste with a sulfur ratio of 0.75 at 200 °C. The films comprised single-crystal nanoparticles with a size of 10–20 nm, which were covered with excess sulfur and agglomerated to form pillar-like structures. The amount of excess sulfur increased with an increasing sulfur ratio in the paste. The formation of pillar-like structures was due to the individual nanoparticles being connected by excess sulfur and the evaporation of CO2, H2O, and amine during the thermal reduction of copper formate.

Wet deposition of sulfur and nitrogen in the Jiuzhaigou World Heritage Site, China: Spatial variations, 2010–2022 trends, and implications for karst ecosystem conservation

Excessive sulfur and nitrogen deposition is a threat to natural ecosystems. This study investigated the spatio-temporal changes of wet sulfur and nitrogen deposition in Jiuzhaigou to understand the responses of wet deposition chemistry to local and national air pollutant emission changes and to assess relevant ecological risks. The results show that local emission sources (e.g., tourism, post-earthquake reconstruction, and vegetation damages) largely elevated the concentrations of SO42−, NO3−, NH4+, and Ca2+ at the non-background sites during 2021–2022; However, the gaps of annual sulfur and nitrogen wet deposition fluxes among the background, semi-background, and non-background sites were reduced by annual precipitation. The pH was also higher at the non-background sites due to stronger acid neutralization capacities from crustal dust there, and acid precipitation (pH < 5.6) was not detected at all the sites. During the 2010 to 2022 period, the wet deposition of SO42− and TIN (i.e. total inorganic nitrogen) and the equivalent ratio of SO42−: NO3− generally presented a declining trend at the background and semi-background sites, as a result of regional and national emission reductions. The TIN reduction from 2015 to 2016 to 2021–2022 at the background site was more from wet NH4+ deposition and the site's NO3− concentrations and fluxes were relatively stable. Compared to the critical loads (CLs) of sulfur and nitrogen for acidification and eutrophication, the annual wet and wet+dry deposition fluxes of sulfur and nitrogen were lower in almost the entire watershed, except for the CLmin of nitrogen for acidification in considerable areas. However, all the wet deposition samples were calcite-unsaturated and had annual TIN concentrations higher than the national environmental standard of total nitrogen for surface water. More field investigations are needed to better assess the ecological risks.

Adapting to seasonal temperature variations: A dynamic multi-subunit strategy for sulfur autotrophic denitrification bioreactors

Elemental sulfur autotrophic denitrification (S0AD) processes are temperature-sensitive, presenting a substantial challenge for the practical implementation of S0AD bioreactors. In this study, a comprehensive methodology for designing and operating S0AD bioreactors was developed, effectively managing fluctuations in nitrogen removal efficiency caused by seasonal temperature variations. Initially, the nitrate removal rate was correlated with simulated on-site temperature and nitrate loading, revealing correlation coefficients of k1, k2, k3, and A as 5.42×10−4, −0.41, 0.04, and 0.13, respectively, to establish a mathematical model for predicting S0AD efficiency. Subsequently, by considering influence factors such as dissolved oxygen and dynamic sulfur consumption, the model was employed to accurately design a pilot-scale S0AD bioreactor for a case study. By utilizing an alternative multi-subunit operation, a stable effluent nitrate concentration of less than 8 mg-N/L was maintained throughout the year. Importantly, this approach resulted in a substantial reduction of 76.8% in excessive nitrate removal, sulfur consumption, and sulfate production. This study aims to provide an optimal design and operation strategy for the practical application of S0AD bioreactors, thereby enhancing reliability and cost-effectiveness in the face of seasonal temperature changes.

Analysis of the thermal regime of converting of copper-lead matte with high-sulfur copper concentrate

According to the earlier conclusions about the possibility of direct processing of high-sulfur copper concentrates with copper-lead matte, analysis of the thermal regime of converting was carried out. It is shown that the traditional calculation methods used to calculate autogenous smelting are not entirely correct and require taking into account the effect of excess sulfur on the temperature regime of the process. It has been established that in the process of converting copper-lead mattes, a wide range of temperature variation is observed - from 1027 0С to 1300 0С. When the concentrate is combined with the matte, the temperature regime of the process is stabilized, which ensures the optimal level of SO2 concentration in the gases required for the production of sulfuric acid. Based on the calculation of the material balance of converting copper-lead mattes using the existing technology and with the addition of a concentrate, the structure of the heat balance of the converting process was established. A strong change in the structure of the heat balance is shown, which is explained by the reduction of magnetite with excess sulfur and an increase in heat due to the oxidation of an additional amount of iron sulfide introduced with the concentrate. A comparative analysis of the technological parameters of the 1st converting period of copper-lead mattes calculated by the proposed method with the practical data of a specific metallurgical unit allows assessing the degree of approximation of the processes occurring in the unit until the thermodynamic equilibrium.

Co/CoS2 Heterojunction Embedded in N, S-Doped Hollow Nanocage for Enhanced Polysulfides Conversion in High-Performance Lithium-Sulfur Batteries.

Modulating the electronic configuration of the substrate to achieve the optimal chemisorption toward polysulfides (LiPSs) for boosting polysulfide conversion is a promising way to the efficient Li-S batteries but filled with challenges. Herein, a Co/CoS2 heterostructure is elaborately built to tuning d-orbital electronic structure of CoS2 for a high-performance electrocatalyst. Theoretical simulations first evidence that Co metal as the electron donator can form a built-in electric field with CoS2 and downshift the d-band center, leading to the well-optimized adsorption strength for lithium polysulfides on CoS2 , thus contributing a favorable way for expediting the redox reaction kinetics of LiPSs. As verification of prediction, a Co/CoS2 heterostructure implanted in porous hollow N, S co-doped carbon nanocage (Co/CoS2 @NSC) is designed to realize the electronic configuration regulation and promote the electrochemical performance. Consequently, the batteries assembled with Co/CoS2 @NSC cathode display an outstanding specific capacity and an admirable cycling property as well as a salient property of 8.25mAhcm-2 under 8.18mgcm-2 . The DFT calculation also reveals the synergistic effect of N, S co-doping for enhancing polysulfide adsorption as well as the detriment of excessive sulfur doping.

Use of Sulfur Waste in the Production of Metakaolin-Based Geopolymers

This preliminary study introduces the incorporation and chemical stabilization of sulfur waste into a geopolymer matrix and explores the concept of material production for further environmental and engineering solutions. In this study, a novel synthesis procedure for sulfur-based geopolymers was introduced, and the role of sulfur in geopolymers and its optimal content to obtain a stable structure were explored. Geopolymers were synthesized by dissolving sulfur in an alkaline activator in different proportions. The alkaline solution was then mixed with metakaolin to synthesize the geopolymer matrix. Adding sulfur in amounts from 0 wt.% to 5 wt.%, compared with metakaolin, led to an increase in the compressive strength of the geopolymers from 22.5 MPa to 29.9 MPa. When sulfur was between 5 wt.% and 15 wt.%, a decrease in the compressive strength was observed to 15.7 MPa, which can be explained by defects and voids in the geopolymer’s microstructure due to the solubility of excess sulfur. Because of the incorporation of sulfur into the geopolymers, a compact and dense microstructure was formed, as reported in the SEM analysis. An XRD analysis showed that, besides quartz and analcime, a new phase, Al2·H10·O17·S3, was also formed as a result of sulfur dissolution in the alkaline activator of the geopolymers.

Elucidating the Volcanic-Type Catalytic Behavior in Lithium-Sulfur Batteries via Defect Engineering.

Defects are generally considered to be effective and flexible in the catalytic reactions of lithium-sulfur batteries. However, the influence of the defect concentration on catalysis remains ambiguous. In this work, molybdenum sulfide with different sulfur vacancy concentrations is comprehensively modulated, showing that the defect level and the adsorption-catalytic performance result in a volcano relationship. Moreover, density functional theory and in situ experiments reveal that the optimal level of sulfur defects can effectively increase the binding energy between molybdenum sulfide and lithium polysulfides (LiPSs), lower the energy barrier of the LiPS conversion reaction, and promote the kinetics of Li2S bidirectional catalytic reaction. The lower bidirectional catalytic performance incited by excessive or deficient sulfur defects is mainly due to the deformed geometrical structures and reduced adsorption of key LiPSs on the catalyst surface. This work underscores the imperative of controlling the defect content and provides a potential approach to the commercialization of lithium-sulfur batteries.

Melatonin Reverses High-Temperature-Stress-Inhibited Photosynthesis in the Presence of Excess Sulfur by Modulating Ethylene Sensitivity in Mustard.

Melatonin is a pleiotropic, nontoxic, regulatory biomolecule with various functions in abiotic stress tolerance. It reverses the adverse effect of heat stress on photosynthesis in plants and helps with sulfur (S) assimilation. Our research objective aimed to find the influence of melatonin, along with excess sulfur (2 mM SO42-), in reversing heat stress's impacts on the photosynthetic ability of the mustard (Brassica juncea L.) cultivar SS2, a cultivar with low ATP-sulfurylase activity and a low sulfate transport index (STI). Further, we aimed to substantiate that the effect was a result of ethylene modulation. Melatonin in the presence of excess-S (S) increased S-assimilation and the STI by increasing the ATP-sulfurylase (ATP-S) and serine acetyltransferase (SAT) activity of SS2, and it enhanced the content of cysteine (Cys) and methionine (Met). Under heat stress, melatonin increased S-assimilation and diverted Cys towards the synthesis of more reduced glutathione (GSH), utilizing excess-S at the expense of less methionine and ethylene and resulting in plants' reduced sensitivity to stress ethylene. The treatment with melatonin plus excess-S increased antioxidant enzyme activity, photosynthetic-S use efficiency (p-SUE), Rubisco activity, photosynthesis, and growth under heat stress. Further, plants receiving melatonin and excess-S in the presence of norbornadiene (NBD; an ethylene action inhibitor) under heat stress showed an inhibited STI and lower photosynthesis and growth. This suggested that ethylene was involved in the melatonin-mediated heat stress reversal effects on photosynthesis in plants. The interaction mechanism between melatonin and ethylene is still elusive. This study provides avenues to explore the melatonin-ethylene-S interaction for heat stress tolerance in plants.

THERMAL-POWER-PLANT CONDENSER-TUBE CORROSION ANALYSIS

The thermal-power-plant condenser tubes, conducting cooling seawater, experienced frequent leakages, prompting the hereby presented failure analysis. Visual inspection of the corroded/ruptured tube segments revealed that localized corrosion may be linked to seawater sediments and thick layers of corrosion products at the tube water side. Sediments were found along the tube bottom and thick corrosion products were found adjacent to the point of contact between the baffle plates and the exterior tube walls. Underdeposit corrosion, accelerated due to sulphate-reducing bacteria, was diagnosed based on the excess sulphur found at the pit bottom using EDX, the FT-IR spectrum indicating the presence of biofilm and SEM determining the featuring corrosion products based on the biofilm. It was proposed that the corrosion initiating deposits were linked to the condenser shutdown and startup periods. Results showed that pitting corrosion occurred under the influence of biofilm microorganisms tolerant to copper. The main goal of this research was achieved by defining a systematic procedure for avoiding a shutdown of the thermal power plant.

Toolbox of Advanced Atomic Layer Deposition Processes for Tailoring Large-Area MoS2 Thin Films at 150 °C.

Two-dimensional MoS2 is a promising material for applications, including electronics and electrocatalysis. However, scalable methods capable of depositing MoS2 at low temperatures are scarce. Herein, we present a toolbox of advanced plasma-enhanced atomic layer deposition (ALD) processes, producing wafer-scale polycrystalline MoS2 films of accurately controlled thickness. Our ALD processes are based on two individually controlled plasma exposures, one optimized for deposition and the other for modification. In this way, film properties can be tailored toward different applications at a very low deposition temperature of 150 °C. For the modification step, either H2 or Ar plasma can be used to combat excess sulfur incorporation and crystallize the films. Using H2 plasma, a higher degree of crystallinity compared with other reported low-temperature processes is achieved. Applying H2 plasma steps periodically instead of every ALD cycle allows for control of the morphology and enables deposition of smooth, polycrystalline MoS2 films. Using an Ar plasma instead, more disordered MoS2 films are deposited, which show promise for the electrochemical hydrogen evolution reaction. For electronics, our processes enable control of the carrier density from 6 × 1016 to 2 × 1021 cm-3 with Hall mobilities up to 0.3 cm2 V-1 s-1. The process toolbox forms a basis for rational design of low-temperature transition metal dichalcogenide deposition processes compatible with a range of substrates and applications.

Effects of Sulfate on the Physiology, Biochemistry, and Activity of Group 1 Sulfate Transporters in Seedlings of Brassica pekinensis

It is well known that some plants have the capability of taking up sulfur as a nutrient from the atmosphere through foliar absorption and can survive well in polluted environments. In order to observe the effects of the relationship between atmospheric hydrogen sulfide (H2S) deposition and soil sulfur nutrition, the current study used Brassica pekinensis as a model plant. The objective in conducting this study was to understand the regulatory mechanisms engaged in the uptake and assimilation of sulfate (SO42−) in plants by studying the modulation of transcription levels of sulfate transporter genes (STGs) (Sultr1;1 and Sultr1;2), changes in growth physiology, and the potential of roots to uptake the SO42− when allowed to grow in the presence or absence of SO42− in a hydroponic nutrient solution. Changes in growth, physico-chemical parameters, and gene expression levels of Group 1 STGs were observed when sulfur-treated and non-treated plants were exposed to phytotoxic H2S levels in the air. Sulfur deficiency enhanced nitrate and free amino acid (FAA) concentrations in the shoot and root regions of the plant. However, there was a significant decrease in the biomass, shoot/root ratio (SRR), chlorophyll content, and thiol content, with p-values &lt; 0.01. This, in turn, increased the sulfur-uptake capacity of plants from the atmosphere through foliar absorption. When the sulfur-uptake capacity of plants increased, there was an increase in the expression level of Group 1 sulfate transporter genes (Sultr1;1 and Sultr1;2), which regulate sulfur transportation through roots. The growth, physico-chemical characteristics, and level of gene expression of Group 1 STGs were unaffected by the availability of excess sulfur in the atmosphere of up to 0.3 μL l−1.

Improving the quality of converting products by the joint smelting of high-sulfur copper concentrate with copper-lead matte

The paper presents the results of studies on the processing of copper-lead mattes with high-sulfur copper concentrate in a converter. The effect of high-sulfur copper concentrate on the quality of converting products is shown. Based on the obtained results, a comparative analysis of the technological indicators of the 1st period of converting copper-lead mattes according to the existing technology and in the joint processing of copper-lead mattes with copper concentrate was carried out. It has been established that when the high-sulfur copper concentrate is used as a sulfidizing agent, excess sulfur released as a result of the dissociation of higher sulfides is completely absorbed by the slag melt. It is shown that elemental sulfur, interacting with oxides of non-ferrous metals and impurities, has a significant effect on the equilibrium distribution of metals between the converting products and their extraction into targeted products. The influence of sulfur on the destruction of magnetite in the process of converting was also established. New data on the distribution of non-ferrous and associated metal impurities (As, Sb, etc.) were obtained during the conversion of copper-lead mattes with high-sulfur copper concentrate. High values were established for the extraction of non-ferrous metals and impurities into targeted products: copper into matte - up to 98%, lead, zinc, arsenic, and antimony into dust - 87%, 91%, 84%, and 38%, respectively. The possibility of a significant improvement in technical and economic indicators, the quality of converting products, and environmental protection during the joint smelting of high-sulfur copper concentrate with a copper-lead matte are shown. The developed technology for converting copper-lead mattes, with high-sulfur copper concentrate, is easily integrated into the plant structure of Kazzinc LLP without any special material costs.

Heat Soaking for Improving Rollover From S at the Back of CIGSSe Solar Cells

A simple method of low-temperature heat-soaking (HS) treatment on copper indium gallium sulfur selenide (CIGSSe) solar cells is investigated for mitigating the rollover effect. Excessive sulfur accumulation on the backside of the CIGSSe absorber leads to downward valence band bending and forms a Schottky barrier, resulting in the rollover current–voltage characteristic at room temperature. HS treatment effectively reduces current saturation in the first quadrant of the current–voltage curves and improves cell efficiency on average by more than 6%. The depth profile on exfoliated CIGSSe absorbers from the Auger electron spectroscopy analysis demonstrates the elemental redistribution, indicating that HS treatment can change the profile gradient of sulfur. The width of sulfur accumulation is significantly reduced after HS, which enables Fowler–Nordheim tunneling by Schottky barrier width shortening. This study showcases a straightforward process and easy-to-implement strategy to reduce the second reverse diode effect caused from the sulfurization process.