Manganese Sulfide Research Articles

Crystal Form-Dependent MnS for Diabetic Wound Healing: Performance and Mechanistic Insights.

In pharmaceuticals, the structural and functional alterations induced by biotransformation are well-documented. Many pharmaceuticals exist in various crystal forms, which govern their transformation and significantly impact their activity. However, in the field of inorganic nanomedicine, there is a paucity of research focusing on the influence of crystal form-dependent "metabolism" (transformation) on their activity and biomechanism. This study delves into the distinct performances of two crystal forms of manganese sulfide (MnS), namely α-MnS and γ-MnS, in bacteria-infected diabetic wound healing. In the initial stage of a wound, where the environment is neutral to slightly alkaline, MnS partially converts to MnxOy (comprising Mn2O3 and Mn3O4) and concurrently produces hydrogen sulfide (H2S); the conversion efficiency of γ-MnS significantly surpasses that of α-MnS. Additionally, γ-MnS is more soluble than α-MnS, which allows it to generate more Mn2+. These components collectively contribute to the superior bacteriostatic properties of MnS. In wound related cells, MnS stimulates the production of collagen I and vascular endothelial growth factor (VEGF), promote the M1 macrophages polarizing to the M2 phenotype, for extracellular matrix (ECM) remodeling. Notably, different transformation products have distinct functions. Consequently, the activity of MnS is dependent on its original crystal form related solubility and transformation efficiency.

Enhanced hydrogen evolution performance of twinned Mn0.65Cd0.35S with Zn-doped cadmium selenide under visible light irradiation

The cadmium manganese sulfide, despite being recognized as a highly efficient photocatalytic semiconductor for hydrogen evolution, faces significant challenges in terms of charge recombination when used solely as a catalyst for photocatalytic hydrogen production. The construction of heterojunction photocatalysts is regarded as one of the effective strategies to enhance the efficiency of photocatalytic hydrogen production. In this work, Zn-doped CdSe was adopted to enhance the photocatalytic active sites of the twinned Mn0.65Cd0.35S. As results, the photocatalytic hydrogen evolution of Zn–CdSe-1/T-MCS-40 can reach approximately 47447.15 μmol g−1 after 5 h, representing a 15 times increase compared to Mn0.65Cd0.35S. Besides, the hydrogen evolution rate shows almost no significant attenuation after four consecutive cycles (20 h). The significant achievement can be largely attributed to the successful construction of an S-scheme heterojunction of Zn–CdSe-1/T-MCS-40, which effectively minimized the charge transfer distance and suppressed the recombination of photo-generated electron-hole pairs. Additionally, the incorporation of Zn-doped CdSe significantly expands the response range to visible light, thereby providing a conceptual framework for advancing the design of solar-to-chemical energy conversion and effectively guiding the fabrication of metal sulfide-based photocatalytic heterojunctions.

Investigation of Sulfur Influence on the Atomization of Stainless Steels

In this study, the alloying of stainless steels with various sulfur contents is investigated to obtain steel powders with significantly reduced mean diameters without changing the operational parameters of the atomizing unit. The steels are produced in a VIM12 furnace and atomized on a VIGA‐1B setup with high‐pressure argon. The desired reduction in the mean diameter is attributed to the decrease in surface tension with increasing sulfur content, which is in good agreement with previous findings. A transition from a positive to a negative thermal gradient of the surface tension is observed, along with a shift to higher temperatures with increasing sulphur concentration. In addition, the chemical assessment of the powders reveals a lower evaporation of manganese and a reduced increase in nitrogen content with increasing sulfur content. The sphericity and flowability are not affected by the addition of sulfur. Viscosity and density measurements are also conducted to characterize the steels thoroughly. Scanning electron microscopy reveals the presence of manganese sulfide, which was submicron in size and well distributed. Iron sulfides, mostly attributed to hot shortness, were not observed, which was also confirmed by thermodynamic modeling using Thermo‐Calc software.

Preparation of MnS/NiCo2S4 composite nanosheets self-supported electrode and the performance in water-system asymmetric supercapacitors

Abstract In this paper, the MnS@NiCo2S4 composite self-supporting electrode was designed and prepared with a mixture of nickel, cobalt, and manganese sulfide as the research object. The capacitance of the electrode can reach 2, 372.7 F g−1 at the current density of 1 A g−1, and the voltage window can also be widened to 0-0.6 V and maintains a multiplier performance of 62.1% at 10 A g−1. Following 5, 000 cycles of charging and discharging, the electrode exhibits a capacity retention of 78.2% relative to its initial capacity, with the coulombic efficiency consistently hovering around 100%. This performance indicates that the electrode can carry out stable and reversible electrochemical processes. A supercapacitor assembled with 1 M KOH as the electrolyte, activated carbon as the anode, and MnS/NiCo2S4 as the cathode, delivers an energy density of 46.9 W h kg−1. In the life test of the charge and discharge cycle, the discharge capacity after 10, 000 cycles is 89.2% of the initial capacity, indicating that the device has good cycle stability. This study provides an idea for the potential application of metal sulfide-based electrodes with wide potential windows and high electrochemical properties in water asymmetric supercapacitors.

Remaining Fatigue Strength of an Orthotropic Steel Deck with Respect to a Repair Method by Cold Joining Techniques

AbstractThe increased traffic loads of the last decades led to an overload of the existing infrastructure. Especially for orthotropic steel decks of bridges, which are prone to fatigue fractures, this have led to structural damages of different categories. With respect to category 2 damages and their retrofit, this paper presents results of fatigue tests on the nonwelded constructional details of an old, demolished orthotropic steel deck. The samples were extracted from a highway bridge with an orthotropic steel deck built in Germany in the 1970s. In comparative fatigue tests on identical constructional details made of new material with the same steel grade, the remaining fatigue strength was determined. Based on the problem of manganese sulfides in old steels the potential of the repair method by cold joining techniques was emphasized. Characteristic load‐bearing capacities for a Eurocode 3‐compliant design of a structural blind fastener were determined and their use in a pilot project was reported.

Hydrometallurgical Synthesis of Cuboidal Manganese Sulfide (MnS) from Low-Grade Manganese Ores and Their Application as Energy Material

Hydrometallurgical Synthesis of Cuboidal Manganese Sulfide (MnS) from Low-Grade Manganese Ores and Their Application as Energy Material

Binder-free copper manganese sulfide nanoflake arrays electrodeposited on reduced graphene oxide-wrapped nickel foam as an efficient battery-type electrode for asymmetric supercapacitors

In the current study, 2D interconnected copper manganese sulfide (CMS) nanoflake arrays are successfully electrodeposited on nickel foam (NF) and reduced graphene oxide-coated NF (NF/rGO). A pulsed current electrodeposition method is used to prepare a uniform and homogeneous coverage of rGO on NF. By using rGO as a conductive carbon-based template, an ultrathin nanoflake structure of CMS with smaller dimensions and higher electrochemically active surface area (ECSA) is achieved. The results reveal the battery-type behavior of the as-synthesized CMS electroactive materials. At a current density of 5 A g−1 this electrode delivers a significant specific capacity of 667 C g-1 and maintained a considerable proportion of its initial capacity, with a retention value of 83.2 % even after undergoing 3000 charge/discharge cycles. In addition, an asymmetric supercapacitor is fabricated by setting up the synthesized NF/rGO/CMS sample as the positive electrode and activated carbon as the negative electrode. The constructed device not only delivers an impressive energy density of 63.3 Wh kg-1 accompanied by an outstanding power density of 11214.5 W kg−1, but also exhibits a considerable cycling durability, enduring only a 12 % decline in specific capacitance after 3000 charge/discharge cycles at a current density of 5 A g−1.

Assemble of porous heterostructure thin film through CuS passivation for efficient electron transport in dye-sensitized solar cells

Three different modified solar cells have been passivated with copper sulfide (CuS) on a TiO2 electrode and manganese sulfide (γ‐MnS) hexagonal as photon absorbers. The MnS were prepared using (a-c) bis(N‐Piperl‐N‐p‐anisildithiocarbamato)Manganese(II) Complexes Mn[N-Piper‐N‐p‐Anisdtc] as (MnS_1), N‐p-anisidinyldithiocarbamato Mn[N‐p-anisdtc] as (MnS_2) and N‐piperidinyldithiocarbamato Mn[N‐piperdtc] as (MnS_3). The corresponding passivated films were denoted as CM-1, CM-2, and CM-3. The influence of passivation on the structural, optical, morphological, and photochemical properties of the prepared devices has been investigated. Raman spectra show that the combination of this heterostructure is triggered by the variation in particle size and surface effect, thus resulting in good electronic conductivity. The narrow band gaps could be attributed to good interaction between the passivative materials on the TiO2 surface. CM-2 cells, stability studies show that the cell is polarized and current flows due to electron migration across the electrolyte and interfaces at this steady state. The cyclic voltammetry (CV) curve for the CM-3 with the highest current density promotes the electrocatalytic activity of the assembled solar cell. The catalytic reactions are further confirmed by the interfacial electron lifetimes in the Bode plots and the impedance spectra. The current–voltage (J–V) analysis suggests that the electrons in the conduction band of TiO2/CuS recombine with the semiconductor quantum dots (QDs) and the iodolyte HI-30 electrolyte, resulting in 5.20–6.85% photo-conversions.

Al2O3-MnS Inclusions and Pitting Corrosion in the Weld Heat-Affected Zone

Manganese sulfide inclusions have been identified as a key factor contributing to the degradation of pitting corrosion resistance in both carbon and stainless steels. However, the precise reasons behind the differential reactivity of various sulfides, with some serving as active sites for pitting while others remain inactive, are not yet fully understood. The effect of debonding occurring at the interface between these inclusions and the steel matrix in relation to pitting corrosion has not been extensively investigated. In this study, an examination of a service-exposed pipeline girth weld was conducted. Immersion testing in blowdown water and multiscale characterization techniques investigated the inclusion-matrix interface debonding within the heat-affected zone. Our findings suggest that interfacial debonding is more likely at the Al2O3- MnS cluster interface. This observation offers a rationale for the selective reactivity of sulfides that form clusters with oxides, highlighting the likelihood that only sulfides clustering with oxides act as active pitting initiation sites.

Effect of small amounts of cerium on impact toughness and tensile properties of industrial Al-killed steel Q355D

The influence of cerium (Ce) on the mechanical properties of industrial steel was meaningful. And inclusions, grains, impact toughness, and tensile properties of industrial aluminium-killed Q355D were investigated by adding varying amounts of Ce. It was found that (i) inclusion of the sample without Ce was mainly manganese sulphide (MnS) and Al2O3-Mn(Ca)S, inclusion of the sample with adding 0.0017% Ce was mainly MnS- and Ce-based inclusions of CeAlO3–Ce2O2S–CaS, and inclusion of the sample with adding 0.0025% Ce was mainly MnS- and Ce-based inclusions of CeAlO3–Ce2S3–Mn(Ca)S; (ii) the number of MnS inclusions had decreased and shortened by increasing Ce. Meanwhile, Ce-based inclusions moved in the direction of decreasing size by increasing Ce; (iii) the grains were refined by adding Ce. In particular, fine acicular ferrite was formed by adding 0.0017% Ce; and (iv) the low-temperature impact toughness was best, and yield strength was the highest for the sample with adding 0.0017% Ce, which was attributed to the contribution of fine acicular ferrite and Ce2O2S inclusion.

Effects of oxygen content, Mn/S ratio, Cu content, hot-rolling, and annealing on morphology/distribution of MnS inclusions and microstructure/mechanical properties of free-cutting stainless steel

Free-cutting steel, renowned for its exceptional machinability, is susceptible to the impact of manganese sulfide (MnS) and other non-metallic inclusions on the cutting performance and mechanical properties. The composition, morphology, and distribution of these inclusions are influenced by the total oxygen content and doping elements in free-cutting steel. This study focused on three S303 free-cutting steels with different S, Mn, and Cu contents, and the as-received samples were subjected to deoxidation and oxidation remelting, respectively, using a high-vacuum arc melting furnace to control the oxygen content. Thermo-Calc simulations were employed to predict the phases and phase proportions under different processing conditions and to compare with measurements. While the oxygen content was found to subtly affect the distribution and morphology of MnS inclusions, the Mn/S ratio notably affected the size and quantity of MnS inclusions, consequently impacting the mechanical properties of the steel. Higher Cu contents resulted in Cu segregates in the matrix but did not exist in MnS or form CuO; however, it significantly reduced strain hardening. Comparisons between hot-rolled and annealed samples revealed that the most significant changes in mechanical properties resulted from the release of residual stresses. In nanoindentation tests, it was observed that the hardness of MnS inclusion was influenced mainly by residual stresses not doping elements.

Research on hydrogen sulfide removal from water using a hydroejector

The war in Ukraine has significantly impacted the country's water resources, leading to deteriorated water quality, threats to drinking water supplies, and long-term environmental issues. Intensive pollution of surface water sources has necessitated increased use of groundwater for drinking purposes. The quality of groundwater in Ukraine varies greatly, often containing concentrations of iron, manganese, hardness salts, and hydrogen sulfide that exceed acceptable limits. Hydrogen sulfide concentrations in different regions range from 1 to over 20 mg/dm³, far exceeding the permissible limit of 0.05 mg/dm³ for drinking water. In the southern regions of Ukraine, such as Kherson, Mykolaiv, and Odesa oblasts, hydrogen sulfide levels exceed the norm by more than 100 times. Existing water purification methods for hydrogen sulfide require the construction of expensive aeration facilities with various loadings, biological reactors, and oxidation filters, which entail significant capital and operational costs. Moreover, these facilities do not always ensure the desired water quality. Therefore, developing new methods and technologies aimed at intensifying hydrogen sulfide removal from water, along with various devices and structures for their implementation, is a pressing issue related to supplying the population with quality water. Among the developed approaches, the use of aeration as an independent method for purification is notable; however, it is used for low hydrogen sulfide concentrations and is most effective at low water pH levels. This article presents the results of experimental studies on the purification of groundwater from hydrogen sulfide by aeration using a hydroejector. Optimal parameters for the hydrogen sulfide removal process, depending on its concentration and water pH, were determined. The effectiveness of water purification using the hydroejector was substantiated and investigated. The key operational parameters of the hydroejector were established.

Designing high-performance hybrid supercapacitors and electrochemical sensors with carbon nanotube-embedded silver manganese sulfide@AC@NF composites

Recently, there has been a lot of interest in hybrid supercapacitors due to their amazing capacity to store energy, surpassing the energy storage capability of both conventional supercapacitors and batteries. In this work, physical integration of silver manganese sulphide (AgMnS) into carbon nanotubes was achieved using hydrothermal synthesis. A comprehensive evaluation was conducted on the material's electrical characteristics. With this composite functioning as the positive electrode and activated carbon (AC) acting as the negative, an asymmetric device configuration was used. The AgMnS@CNT composite demonstrated a notable specific capacity of 358.0C/g at a 2.0 A/g rate. The material demonstrated a remarkable 49.5 Wh/kg energy density and a remarkable 1505.0 W/kg power density. 83.3 % of the initial capacity of the composite material remained even after 5000 cycles. This illustrates its continued stability and suggests that its operating lifetime may be increased. Besides; the hybrid electrode is used to detect the glucose in the specimen up to 0 mM to 2 mM. The electrochemical device showed a remarkable value of sensitivity of 1402 μA·cm−2 mM−1. As the field of energy storage technology develops, this dynamic composite may reveal completely new and exciting options.

Separation of Damage Mechanisms in Full Forward Rod Extruded Case-Hardening Steel 16MnCrS5 Using 3D Image Segmentation.

In general, formed components are lightweight as well as highly economic and resource efficient. However, forming-induced ductile damage, which particularly affects the formation and growth of pores, has not been considered in the design of components so far. Therefore, an evaluation of forming-induced ductile damage would enable an improved design and take better advantage of the lightweight nature as it affects the static and dynamic mechanical material properties. To quantify the amount, morphology and distribution of the pores, advanced scanning electron microscopy (SEM) methods such as scanning transmission electron microscopy (STEM) and electron channeling contrast imaging (ECCI) were used. Image segmentation using a deep learning algorithm was applied to reproducibly separate the pores from inclusions such as manganese sulfide inclusions. This was achieved via layer-by-layer ablation of the case-hardened steel 16MnCrS5 (DIN 1.7139, AISI/SAE 5115) with a focused ion beam (FIB). The resulting images were reconstructed in a 3D model to gain a mechanism-based understanding beyond the previous 2D investigations.

CoMnS@rGO nanocomposite grown on NF for high-performance supercapacitor-battery hybrid device and advancing electrochemical sensitivity

The co-electrodeposition approach has been widely used to synthesize the transition metal sulfides/oxides because of remarkable performance of the energy storage devices. In this research, cobalt manganese sulfide (CoMnS) binary compounds are synthesized using the co-electrodeposition approach. The main objective is to investigate the optimal number of depositing periods in cyclic voltammetry while maintaining a constant scan rate. The electrodes without binders are produced using a rapid synthesis approach, which involves assessing binary metal sulfide to achieve a significantly enhanced energy storage capacity. Further, the rGO is incorporated into the CoMnS to enhance the electrochemical properties. The CoMnS@rGO electrode showed the specific capacitance (Cs) of 2357 F/g because of the small equivalent series resistance values as determined through electrochemical impedance spectroscopy (EIS) measurement, indicating a higher level of conductivity. The hybrid electrode showed high values of energy and power densities of 50.8 Wh/kg and 3440 W/kg, respectively. Besides, the nanocomposite electrode is used as a chemical sensor and precisely detects the multiple elements. The estimated value of R2 is 0.994 because of the high sensitivity. The hybrid electrode showed a signal-to-noise ratio (S/N) of 5. Furthermore, based on four observations, the comparative standard deviation (RSD) is calculated to be 1.9 %. The device showed high electrochemical glucose detection sensitivity. The nanocomposite-based electrodes provide a platform for designing novel multifunctional devices.

Self-assembled nano-MnS@N,P dual-doped lignite based carbon as high-performance sodium-ion batteries anode

Manganese sulfide (MnS) is a suitable electrode material for use in sodium-ion batteries (SIBs) due to its high theoretical capacity and low cost. However, its practical application is still hampered by disadvantages such as large volume expansion during charging/discharging and limited cycle life. Therefore, reasonable structural design is of great importance in order to achieve an excellent sodium storage performance of the electrode materials for SIBs. Herein, nano-MnS@N,P dual-doped lignite based porous carbon (MnS@N,P-LPC) composite with a single MnS cube encapsulated in an N,P dual-doped lignite derived porous C is successfully prepared as superior anode material for SIBs. The multilayer pore structure and the combined effect of N and P dual-doping can enhance electrochemical performance by supplying more sodium storage sites. After 200 cycles at 0.1 A g−1, the composite complex produced a maximum capacity of 519 mA h g−1 and demonstrated a capacity of 392.5 mA h g−1 even at 1.6 A g−1. It exhibits outstanding cycling stability and superior rate performance. This excellent electrochemical performance is ascribed to the presence of the multilayer pore N,P dual-doped C skeleton, which effectively addresses the volume expansion of MnS particles during charging/discharging and facilitates efficient transport of ions and electrons through an effective conductive network.

Continuous and controllable synthesis of MnO2 adsorbents for H2S removal at low temperature

H2S is an extremely noxious impurity generated from nature and chemical industrial processes. High performing H2S adsorbents are required for chemical industry and environmental engineering. Herein, α-, γ-, and δ-MnO2 adsorbents with high sulfur capacity were synthesized through a continuous-flow approach with a microreactor system, achieving much higher efficiency than hydrothermal methods. The relationship between crystal structure and synthesis conditions such as residence time, reaction temperature, concentration of K+ in solution and reactant ratio is discussed. According to the H2S breakthrough tests at 150 °C, continuously prepared α-, γ-, and δ-MnO2 exhibited sulfur capacities of 669.5, 193.8 and 607.6 mg S/g sorbent, respectively, which was at a high level among the reported adsorbents. Such enhanced performance is related to the large surface area and mesopore volume, high reducibility, and a large number of oxygen species with high reactivity and mobility. Manganese sulfide and elemental sulfur were formed after desulfurization, which indicated the reaction consisted of two steps: redox and sulfidation of the sorbents. This study provides an innovative design strategy for the construction of nanomaterials with high H2S adsorption performances.

High-temperature treatment of functional Heusler alloy Ni46Mn41In13 thin foils for microsystem devices and electronics

In this study, the high-temperature transformation in a thin foil of non-stoichiometric Heusler alloy based on Ni-Mn-In is investigated using in-situ TEM. The highly ordered cubic L21 phase undergoes decomposition upon heating, forming a phase with a composition close to Ni75Mn25, which is identified as disordered FCC-Ni3Mn and secondary phases, mainly manganese oxides and sulfides. All phases formed upon heating to a temperature of 1173 K are preserved during the in-situ cooling experiment to a temperature of 123 K.

A Novel CRISPR/Cas9‐Encapsulated Biomimetic Manganese Sulfide Nanourchins for Targeted Magnetic Resonance Contrast Enhancement and Self‐Enhanced Chemodynamics‐Gene‐Immune Synergistic Tumor Therapy

AbstractCRISPR/Cas9 gene editing systems are widely studied in cancer therapy, however, it is still challenging to improve the gene editing efficiency and enhance the anticancer efficacy. Herein, a novel self‐assembled manganese sulfide nanourchin with CRISPR/Cas9 and hybrid membrane encapsulation (MCRT) is developed to highlight the synergistic mechanism of hydrogen sulfide (H2S) and CRISPR/Cas9 in cancer therapy. The special structure and cationic surface of nanourchins facilitate the loading of CRISPR/Cas9 with the large size and the encapsulation of erythrocyte‐tumor cell hybrid membrane, endowing the nanoplatform with long circulation and precise tumor targeting. MCRT with pH‐response can effectively decompose into H2S and Mn2+, and release CRISPR/Cas9 in acidic tumor microenvironment. H2S can up‐regulate intracellular hydrogen peroxide level by inhibiting the activity of catalase, which enables self‐enhanced chemodynamic therapy (CDT) of Mn2+. In addition, H2S can synergize with the released CRISPR/Cas9, co‐downregulating the level of intracellular anti‐apoptotic protein survivin, achieving self‐enhanced gene therapy. Furthermore, systemic delivery of MCRT displays significantly tumor magnetic resonance imaging (MRI) contrast enhancement. Importantly, H2S‐enhanced CDT‐gene therapy simultaneously induces immunogenic cell death and triggered a robust anti‐tumor immune response. Thus, MCRT has a potential application for the targeted MRI and self‐enhanced CDT‐gene‐immune synergistic tumor therapy.

Effect of Metal Carbides on Hydrogen Embrittlement: A Density Functional Theory Study

This study uses plane wave density functional theory (DFT) to investigate the effect of certain metal carbides (Niobium carbide, Vanadium carbide, Titanium carbide, and Manganese sulfide) on hydrogen embrittlement in pipeline steels. Our results predict that the interaction of hydrogen molecules with these metal carbides occurs in the long range with binding energy varying in the energy window [0.043 eV to 0.70 eV].In addition, our study shows the desorption of H2 molecules from these metal carbides in the chemisorptions. Since atomic state hydrogen interacts with NbC, VC, TiC, and MnS to cause embrittlement, we classified the strength of the hydrogen trapping as TiC + H > VC + H > NbC + H> MnS + H. In addition, our study reveals that the carbon site is a more favorable hydrogen-trapping site than the metal one.