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Photo-assisted energy storage systems, by which solar energy can be both converted and stored, have been of interest in the past few years. Novel energy conversion and storage technology is offered by photo-supercapacitors through the combination of an energy collecting unit and a supercapacitor. This dual-application system effectively generates and stores power in a single device, which makes it appropriate for various purposes. In this work, the electrochemical anodization-electrodeposition has been employed to fabricate manganese-nickel sulfide (Mn–Ni–S) nanostructures on titania nanotubes (TNs) and used them as photoelectrodes in photo-supercapacitors. The high surface area and improved properties make TNs considerably important for energy production and storage. Photoelectrochemical analysis was carried out in a three-electrode system under a xenon (Xe) lamp irradiation using the film prepared as the photoelectrode. The highest photocurrent and photovoltage were shown by MnNiS-3/TN electrode, indicating its superior photosensitivity. Upon illumination under a 0.7 mA/cm2 current density, the area-specific capacitance of MnNiS-3/TN electrode increased from 388.3 to 723.3 mF/cm2, which is 2.0, 3.6, and 12.8 times higher than the corresponding values for NiS/TN, MnS/TN, and bare TN electrodes under similar conditions, respectively. This indicates the considerable enhancement of the capacitance of this electrode induced by light. The desirable light-sensitive properties of MnNiS/TN make it capable of simultaneous solar energy harvesting and storage. Light sensitivity makes it possible to charge MnNiS/TN optically. More importantly, upon light irradiation, the capacity can be increased from 374.7 to 630.2 mF/cm2 (current density 0.5 mA/cm2) compared to the corresponding value in the dark. Using MnNiS-3/TN as the best photoelectrode and MnS/FTO, NiS/FTO, MnNiS-1/FTO, MnNiS-2/FTO, and MnNiS-3/FTO as the counter electrodes, photo-charged through light illumination on their surfaces, five asymmetric solid-state photo-supercapacitors (ASSPS) were prepared. MnNiS-3/TN//MnNiS-3/FTO device showed the largest CV curve area, which indicated its highest areal capacitance. High capacitance gain under irradiation (155.7% at 2.0 mA/cm2) and outstanding capacitance maintenance (97.9% over 10000 cycles) were shown by this ASSPS. Furthermore, a great energy density of 4855.4 mWh/cm2 was shown by the MnNiS-3/TN//MnNiS-3/FTO device under light irradiation. This research introduces a novel approach to the development of powerful solar energy conversion/storage devices. [Display omitted] • Mn–Ni sulfides with various Mn/Ni ratios have been grown on titania by co-electrodeposition. • The highest photocurrent and photovoltage were shown by MnNiS-3/TN. • Upon illumination, the area-specific capacitance of MnNiS-3/TN electrode increased from 388.3 to 723.3 mF/cm2. • Using MnNiS-3/TN as the best photoelectrode, five asymmetric solid-state photo-supercapacitors (ASSPS) were prepared. • High capacitance gain under irradiation (155.7% at 2.0 mA/cm2) and outstanding capacitance maintenance (97.9% over 10000 cycles) were shown by this ASSPS. [ABSTRACT FROM AUTHOR]

A high performance lamellar structured Fe-doped MnS/graphene anode has been developed for sodium-ion storage. Due to the synergistic positive effect of graphene confinement, strong Mn S C bonding and Fe-doping, the composite exhibits excellent rate performance and long-term stability. A prototype sodium-ion capacitor fabricated with Fe-MnS/PG anode and nitrogen-doped carbon cathode can deliver both high energy and high power densities. [Display omitted] Manganese sulfide (MnS) is a promising converion-type anode for sodium storage, owing to the virtues of high theoretical capacity, coupled with it crustal abundance and cost-effectiveness. Nevertheless, MnS suffers from inadequate electronic conductivity, sluggish Na+ reaction kinetics and considerable volume variation during discharge/charge process, thereby impeding its rate capability and capacity retention. Herein, a novel lamellar heterostructured composite of Fe-doped MnS nanoparticles/positively charged reduced graphene oxide (Fe-MnS/PG) was synthesized to overcome these issues. The Fe-doping can accelerate the ion/electron transfer, endowing fast electrochemical kinetics of MnS. Meanwhile, the graphene space confinement with strong Mn S C bond interactions can facilite the interfacial electron transfer, hamper volume expansion and aggregation of MnS nanoparticles, stabilizing the structural integrity, thus improving the Na+ storage reversibility and cyclic stability. Combining the synergistic effect of Fe-doping and space confinement with strong Mn S C bond interactions, the as-produced Fe-MnS/PG anode presents a remarkable capacity of 567 mAh/g at 0.1 A/g and outstanding rate performance (192 mAh/g at 10 A/g). Meanwhile, the as-assembled sodium-ion capacitor (SIC) can yield a high energy density of 119 Wh kg−1 and a maximum power density of 17500 W kg−1, with capacity retention of 77 % at 1 A/g after 5000 cycles. This work offers a promising strategy to develop MnS-based practical SICs with high energy and long lifespan, and paves the way for fabricating advanced anode materials. [ABSTRACT FROM AUTHOR]

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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.

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. [ABSTRACT FROM AUTHOR]

Copyright of Iron Steel Vanadium Titanium is the property of Iron Steel Vanadium Titanium Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The crystallographic, optical, and electrical properties of manganese sulfide thin films depend on the control of the temperature precursors in the synthesis process, as shown by the results of this work. MnS thin films were deposited on glass substrates using the SILAR method and over an additional layer of CdS synthesized by chemical bath deposition (CBD) to acquire a p-n heterojunction. SILAR is an inexpensive method performed with a homemade robot in this case. Temperature in the solution precursors varied from 20 to 80 °C in four experiments. The morphology and structure of MnS and FTO/CdS/MnS thin films were studied through scanning electron microscopy (SEM) and grazing-incidence X-ray diffraction (GIXRD); the results indicate that materials showed a polycrystalline behavior, a diffraction peak of α- MnS cubic phase was observed with lattice constants values, ranging from 4.74 to 4.75 Å.Additionally, Raman spectroscopy showed a signal corresponding to the transversal optical phonons of MnS at a wavenumber near 300 cm−1. UV–vis spectroscopy showed optical bandgap values of 3.94, 4.0, 4.09, and 4.26 eV for thin films obtained at 20°, 40°, 60°, and 80 °C.respectively. Results indicated 80 °C as an optimal cationic precursor process temperature, achieving optical transmittance T% and good film quality according to SEM and GIXRD for the synthetization of MnS. The current–voltage (I–V) characterization in the heterojunction showed a characteristic diode curve with an open circuit voltage (VOC) of 300 mV under illumination, which indicated that the manganese sulfide behaves as p-type material contributing with positive charge carriers, while CdS behaves as n-type material.

Supercapattery has emerged as one of the possibilities in the electrochemical energy storage system as a consequence of the expansion of technological advancement and the electrical vehicle sector. Manganese sulfide (MnS) nanoflakes were produced by hydrothermal technique at various heating temperatures (100, 110, 120, and 130 °C). The existence of MnS is revealed by the X-ray diffraction (XRD) diffractogram, and α- and γ-MnS crystals were effectively grown on a nickel (Ni) foam. MnS nanoflakes were seen under a field emission scanning electron microscope (FESEM). The crystalline structure of MnS nanoflakes is susceptible to variation depending on the heating temperature, and at 120 °C, MnS produced nanoflakes with additional wrinkles. Through Brunauer–Emmett–Teller (BET) analysis, the thermal and physical adsorption investigations demonstrated the high total surface area and thermal stability of MnS electrodes. The findings of BET studies demonstrate that MnS-120 has the highest surface BET (SBET) and the smallest pore size distribution (PSD), which later increases the total surface area of MnS nanoflakes for an effective energy storage mechanism. MnS is structurally stable below 200 °C, according to thermogravimetric analysis (TGA). MnS-120 electrode has a maximum specific capacity of 1003.5 C/g at 5 A/g and a 49% rate capability. Supercapattery devices were created in a MnS-120//activated carbon (AC) configuration to assess the real-time performance of the material. The MnS-120//AC demonstrated better efficiency by offering a specific energy of 69.24 Wh/kg at 2953 W/kg. The life cycle test confirmed that MnS-120//AC is stable with a capacity retention value of 96% after 4000 cycles. [ABSTRACT FROM AUTHOR]

A composite of manganese sulfide doped iron oxychloride (MnS-FeOCl) was successfully synthesized for the first time and applied to activate H2O2 to degrade isoniazid under different pH values. The MnS-FeOCl structure was characterized by various analytical methods such as X-ray diffraction (XRD), scanning electron microscopy, energy-dispersive X-ray spectroscopy, Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy, indicating manganese sulfide (MnS) doping greatly changed the physicochemical property of FeOCl. The Fenton-like reaction showed that MnS doping could enhance the Fenton activity of FeOCl in the pH range of 6-9, and 5% MnS-FeOCl composite had the highest activity. Isoniazid (20 mg/L) could be degraded by 89.90% in 5 min at an initial pH of 6.0 by 5% MnS-FeOCl/H2O2. However, the high performance of 5% MnS-FeOCl composite was at the cost of decrease of its stability. The result of XRD analysis indicated that the crystallinity of 5% MnS-FeOCl was poorer than that of pristine FeOCl, thus leading to its decreased stability. It is of great significance for the further study on the modification of FeOCl catalyst in Fenton-like reaction. [ABSTRACT FROM AUTHOR]

Studying the X-ray absorption near-edge structure shows that cation substitution of a MnS matrix with lanthanide atoms does not significantly affect the character of the local environment of metal (manganese, dysprosium, thulium and ytterbium) and sulfur atoms in lanthanide-doped Ln0.05Mn0.95S (Ln = Dy, Tm, Yb) solid solutions. Comparison of the experimental and theoretical data obtained by the finite-difference method has revealed that the main contributions of the unoccupied p- and d-states of manganese and p-states of sulfur are localized at the conduction-band bottom, both in the case of the initial MnS matrix and in the case of lanthanide-substituted Ln0.05Mn0.95S solid solutions. The main contributions of unoccupied f‑states of ytterbium and thulium in Ln0.05Mn0.95S (Ln = Tm, Yb) solid solutions are shifted to the high-energy region of the conduction band, while the f-states of dysprosium in dysprosium-doped Dy0.05Mn0.95S solid solutions are localized near the conduction-band bottom. According to the calculated model spectra, it is found that the contributions of the free lanthanide d-states in Ln0.05Mn0.95S (Ln = Dy, Tm, Yb) solid solutions are shifted to the region of the conduction-band bottom with an increase of the atomic number of the lanthanide atom. [ABSTRACT FROM AUTHOR]

The morphology of MnS inclusion is one of the key elements influencing the machinability of steel. Herein, it is shown in the thermodynamic analysis results that the interaction coefficient causes a 1.2% deviation for the precipitation of MnS in low‐sulfur‐content steel (S1), while the deviation is 14% in high‐sulfur steel (S2), and the content of C and Si is the main element causing the deviation. The microstructure of medium‐carbon steel is mainly pearlite and ferrite. The increase of manganese and sulfur content leads to the decrease of ferrite content and increase of pearlite content. Almost all MnS inclusions in S1 are polyhedral, while S2 contains spherelike, cluster, and polyhedral MnS inclusions. Manganese and sulfur mainly affect the nucleation rate of MnS inclusion, where the number density of MnS in S2 is higher than that in S1, which increases the probability of viscous sintering of MnS inclusions in S2, and form spherelike‐ and rodlike‐polycrystalline MnS particles. Polyhedron inclusions are mostly octahedron, and it is the final equilibrium morphology of sulfide in S1 and S2. [ABSTRACT FROM AUTHOR]

The location of the defect in the CL65 wheel rims was determined by ultrasonic detection, and workblank samples containing the defect were taken out and processed into fatigue samples. Through the fatigue test carried out on Shimadzu electro-hydraulic servo fatigue testing machine, the fatigue life of samples with defects was obtained.After the test, the shape, size and chemical composition of defects were analyzed. The results show that the main component of shrinkage defects is MnS and the main component of inclusion defects is hard oxides. The fatigue life of samples with shrinkage defects is longer than that of samples with inclusion defects. To analyze the difference between the influence of the two defects on the fatigue properties of wheel materials, the finite element models were established based on the tessellated stress theory. Compared with inclusion defects, the tessellated stress at the interface between shrinkage defects and the matrix is significantly reduced and the extent of stress concentration around defects is small. Therefore, the damage of shrinkage defects containing MnS on the fatigue properties of wheel materials is significantly less than that of oxide inclusions.

The construction of hollow nanostructure by compositing with carbonaceous materials is generally considered an effective strategy to mitigate the drastic volume expansion of transition metal sulfides (TMSs) with high theoretical specific capacity in the process of lithium storage. However, designing well‐controlled architectures with extended lithiation cyclic stability, and ease the expansion of the electroactive materials into the reserved hollow spaces still needs to be developed. Herein, using MnS as an example, the hollow double‐shell carbon‐coated TMSs architecture is designed to achieve the controllable operation of shell thickness to regulate interfacial stress. The functional architecture enables the high‐capacity MnS to reach reversible capacities and extended lithiation cycling stability at high current densities. In situ transmission electron microscopy, optical observation characterizations and finite elements are used to analyze the nanoconfined expansion behavior of hollow MnS@C anodes. The as‐designed hollow structure with a carbon shell thickness ≈12.5 nm can effectively restrict the drastic expansion of MnS nanoshell into inner voids with compressive stress. This study demonstrates a general strategy to design functional carbon coating metal sulfides with tailored interfacial stress. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Mechanical Strength / Jixie Qiangdu is the property of Zhengzhou Research Institute of Mechanical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Considering its relatively large specific capacity along with low cost advantages, manganese sulfide (MnS) emerges as a competitive lithium-ion host material. However, some excruciating issues such as inevitable volume expansion and inherent insufficient conductivity always result in a low specific capacity, limited cycling life and poor rate capability. Rational morphology and structure design is vital to achieve superior Li-storage performance. Herein, a heterostructured composite with small MnS embedded on glycine-derived N, S-doped amorphous carbon sheets (MnS@NSC) has been synthesized through an annealing and sulfuration route. MnS nanoparticles are well confined by carbon matrix, which is conductive to an effective suppression on volume change and reservation of integrated structure. Meanwhile, porous carbon framework supplies desirable expressway for fast electron delivery and reduces the distance for lithium ions diffusion. Consequently, the MnS@NSC anode delivers a remarkably elevated lithium-storage performance. [ABSTRACT FROM AUTHOR]

A way to synthesize a Mn2+‐ coordinated polymer precursor ligated by sulfur atoms with acetate counter ions (Mn‐DTOGA) is proposed, which is achieved by an imine formation reaction between dithiooxamide and glutaraldehyde in the presence of manganese (II) acetate. MnS/MnO decorated N, S‐doped carbon nanoparticles (MnS/O‐SNC) are then prepared by calcination of the Mn ion‐coordinated polymer for the practical applications of catalytic reactions. The Mn‐DTOGA and MnS/O‐SNC structures prepared at different temperatures (700, 800, and 900 °C) are characterized using various physical and electrochemical and chemical analyses. The nanoparticles prepared at 900 °C reveal the best performance for the catalytic oxidation of Hydrogen peroxide (H2O2) and bisphenol A. The decomposition potentials of H2O2 (1.0 mm) and bisphenol A (100.0 µm) on the catalyst modified electrode are observed to be +0.40 and +0.15 V (versus Ag/AgCl), respectively. It is observed that the catalytic performances to the oxidation reactions are mainly related to MnO decorated outside the SNC particles compared to MnS formed inside the particles. The electrode reveals a wide dynamic range with the low detection limits for H2O2 (0.08 (±0.02) µm) and bisphenol A (0.17 (±0.04) µm). This study will provide essential clues for the future catalyst design. [ABSTRACT FROM AUTHOR]

In this study, the marine alga Sargassum siliquastrum was used for the first time as a stabilizer for the preparation of manganese sulfide nanoparticles (MnS NPs). After characterization, the resulting MnS NPs were literature-first applied for adsorption of malachite green (MG) cationic dye. Characterizations indicated the formation of a spherical, monodispersed, mesoporous mixture of γ-MnS (56%) and α-MnS (46%) with a small crystallite size of 19 nm and a high surface area of 156.7 m2/g. After stepwise optimization of various parameters affecting the adsorption process, MG was 99.7% removed within 60 min from neutral solution by 0.2 g/L of MnS NPs at 298 K. The data of MG adsorption are best fitted by Langmuir isotherm (R2 ≥ 0.99) with a maximum adsorption capacity of 432.2 mg/g at 328 K. Pseudo-second order (R2 = 0.99) is the most appropriate to describe adsorption kinetics. In addition, thermodynamic results revealed that the adsorption is endothermic and spontaneous. Stability and interference studies showed that MnS NPs are highly stable and more selective for MG removal than other dyes. Upon these results, MnS NPs can be applied for the effective removal of MG from various water samples. [ABSTRACT FROM AUTHOR]

Aiming to achieve high-efficiency bifunctional catalysts, doping engineering is applied to construct bifunctional catalysts for oxygen electrodes in Zn-air batteries to strengthen the catalytic kinetics of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Herein, MnS doped cobalt nitride catalyst (MnS/CoN x) with divergent fiber morphology is prepared by low temperature nitriding for the self-assembling layered double hydroxides (LDH). The MnS/CoN x shows excellent electrical conductivity and improved catalytic activity on ORR and OER with low overpotential of 290 mV at 10 mA cm−2 and a good half-wave potential of 0.80 V in ORR compared with CoNx and MnO/CoN x. The contribution of the increased bifunctional catalytic performance is possible from the more active center Co3+ and Mn4+, and the elevated electron transport resulted from the opportune high conductive MnS doping. The MnS/CoN x catalyst-driven Zn-air battery achieves a higher power density of 228 mW cm−2 and the excellent long-term stability of 500 h at 20 mA cm−2 far surpassing the commercial Pt/C+RuO 2 catalyst. • Heteromolecule doping engineering achieves the bifunctional catalyst MnS-doped CoN x. • High conductive MnS doping motivates the abundant Mn4+ beneficial for the catalytic activity of ORR. • MnS doping tends to induce cobalt oxide with increased high valence Co3+ on CoN x beneficial for the catalytic activity of OER. • Zn-air battery with MnS/CoN x catalyst achieves a higher power density of 228 mW cm−2 and a superior cycle stability over 500 h. [ABSTRACT FROM AUTHOR]

This study investigates a sandwich-like CuS x /MnS x electrode fabricated through electrodeposition technique on nickel foam (NF) substrate for hydrogen evolution reaction (HER) in seawater splitting. The synthesized electrode exhibits plenty of active sites, substantial specific surface area, and a distinctive morphology reminiscent of a tuberose-type nanostructure. Moreover, synergistic activity between the copper and manganese components enhances the rate of electron transfer process, thereby augmenting the electrocatalytic performance. Partial oxidation serves to increase active sites and control the morphology of the nanoparticles. The optimized electrode exhibits a minimal overpotential of 144 mV at 10 mA/cm2 for saline water splitting. The Tafel slope of 197 mV/dec and a transfer coefficient (α) of 0.3 indicate that the rate-determining step for the HER is likely the initial Volmer reaction. A higher electrochemical surface area (ECSA) of 2268 cm2, a solution resistance of 0.84 Ω, and a charge transfer resistance of 5.18 Ω suggest improved ion diffusion in the synthesized electrode. The electrocatalytic performance was also investigated by carrying out experiments with varying alkalinity in natural seawater electrolytes. The catalyst demonstrated robust stability for HER in natural seawater splitting with constant current density after 50 h of chronoamperometric analysis. The facile electrodeposited electrocatalyst exhibits energy-efficient and sustainable performance, effectively catalyzing reactions in a seawater-based electrolyte during the HER. Graphical Abstract Caption: Figure: Synthesis process of sandwich-like CuS x /MnS x electrode for hydrogen evolution in saline water splitting. [Display omitted] • A sandwich-like CuS x /MnS x electrode was prepared for hydrogen evolution in saline water splitting. • Facile electrodeposition approaches were employed for electrode synthesis. • The synthesized electrode exhibited a minimal overpotential of 144 mV at 10 mA/cm2 for saline water splitting. • The catalyst showed 50 h of robust stability in natural seawater splitting activity. [ABSTRACT FROM AUTHOR]

Chemical deposition is used to form thin-film layers of manganese-doped zinc sulfide (ZnS(Mn)) on frosted glass substrates. The films are ~220 nm thick and composed of lenticular-shaped grains with sizes smaller than those of ZnS films. It is found that introducing manganese(II) chloride into the reaction mixture preserves the excess content of the metal over the content of chalcogen. Manganese in amounts of 2.5 ± 0.25 at. % is detected in a film formed at the maximum concentration of MnCl2 in the reactor. X-ray diffraction reveals the formation of amorphous ZnS and ZnS(Mn) layers with short-range order of the environment of atoms with a B4-type hexagonal structure (space group P63mc). The band gap of the films, calculated from optical spectroscopy data, falls from 3.68 to 3.54 eV upon an increase in the content of manganese. It is shown that incorporating manganese into a film results in photoluminescence in the range of 580–620 nm. At the maximum content of manganese, the photoluminescence is approximately double that of ZnS. Luminescence quenching is independent of the concentration of dopant for all film samples and is characterized by a decay period of 13–15 μs. [ABSTRACT FROM AUTHOR]

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 Mn x O y (comprising Mn 2 O 3 and Mn 3 O 4 ) and concurrently produces hydrogen sulfide (H 2 S); 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 Mn 2+ . 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., (© 2024 Wiley‐VCH GmbH.)

The necessity to develop renewable energy resources that are highly durable and flexible with superior energy density and capacitance ability has attracted considerable interest in the field of solar cell research. Semiconducting compound materials that are easily available, hazard-free and cost-effective are emerging as potential solutions to tackle this challenge. Herein, we present multiple molecular precursors used to grow manganese sulfide nanoparticles through a proficient one-step heat-up approach. For all of the tested samples, the X-ray diffraction peaks correspond to a γ-MnS hexagonal wurtzite structure. UV-Vis spectroscopy yielded absorption wavelengths of 359–420 nm and band-gap energies of 3.78–4.0 eV. Photoluminescence analysis shows characteristics of red and blue shift from 451–602 nm. High-resolution transmission electron microscopy (HRTEM) and selected-area electron diffraction (SAED) reveal a narrow size distribution with nanosticks and large contact areas, which are critical for improved catalytic performance. The current study provides an improved pathway to a well-grown and uniform nanocrystal structure for applications in energy devices. [ABSTRACT FROM AUTHOR]

Nanostructured manganese sulfide (MnS) has been verified to be effective to address the issues of MnS as next‐generation anode material in high energy lithium‐ion batteries (LIBs). The scale‐up fabrication, however, is still challenged by the multistep and rigid processes of synthesizing MnS nanoparticles. Herein, by using micro‐sized MnS as low‐cost MnS source, we present a facile, cost‐effective and scalable strategy to prepare a sub‐micrometer sized MnS@NSC composite, in which MnS nanoparticles are encapsulated into N,S‐codoped carbon matrix (NSC) deriving from polyacrylonitrile (PAN). The NSC matrix combined with homogeneously distributed MnS nanoparticles crushed from micro‐MnS provide fast access of lithium ion/electron and robust structure, leading to remarkable cycling stability (551.6 mAh g−1 at 0.5 A g−1 even after 400 cycles) and desirable rate capability (624 mAh g−1 at 0.1 A g−1 and around 300 mAh g−1 at 2 A g−1). Particularly, the assembled LIB full cell by coupling the anode with LiFePO4 (LFP) cathode presents an encouragingly cycling retention of 96 % after 100 cycles. This work provides a new possibility for design and industrial implementation of MnS as advanced anode materials for LIBs. [ABSTRACT FROM AUTHOR]

The effect of Ta addition on the pitting corrosion resistance of duplex stainless steels was investigated in both cases without and with deoxidization/desulfurization by the addition of Al and Ca. The pitting corrosion resistance was improved by the addition of Ta with two proposed mechanisms. For steels without Al and Ca, the MnS inclusions which act as initiation sites of the pitting corrosion are modified to the electrochemically-stable (Ta,Mn) oxysulfides. For steels with Al and Ca, the pitting initiation sites (CaS and (Al,Ca)oxides) are coated with the stable Ta-containing nitrides resulting in the suppression of pitting corrosion propagation. [ABSTRACT FROM AUTHOR]

A concept model for nitrate removal mechanism in MSLAD systems. [Display omitted] • The feasibility of desulfurized products of Mn ore for NO 3 −-N removal was explored. • MSLAD system showed superior NO 3 −-N removal as compared with SLAD and MLAD systems. • MnS and S0 as coupled electron donors showed synergistic effect in denitrification. • γ-MnS showed higher reactivity in nitrate removal than that of α-MnS. Despite the great potential of sulfur-based autotrophic denitrification, an improvement in nitrate removal rate is still needed. This study used the desulfurized products of Mn ore to develop the MnS-S0-limestone autotrophic denitrification system (MSLAD). The feasibility of MSLAD for denitrification was explored and the possible mechanism was proposed. The nitrate (100 mg/L) was almost removed within 24 h in batch experiment in MSLAD. Also, an average TN removal of 98 % (472.0 mg/L/d) at hydraulic retention time of 1.5 h in column experiment (30 mg/L) was achieved. MnS and S0 could act as coupled electron donors and show synergistic effects for nitrate removal. γ-MnS with smaller particle size and lower crystallinity was more readily utilized by the bacterium and had higher nitrate removal efficiency than that of α-MnS. Thiobacillus and Sulfurimonas were the core functional bacterium in denitrification. Therefore, MnS-S0-limestone bio-denitrification provides an efficient alternative method for nitrate removal in wastewater. [ABSTRACT FROM AUTHOR]

With the low electronegativity of sulfur to oxygen, metal sulfides have become of much interest in energy storage system application, due to their high redox reactive sites and structure stability. However, composite of two or more metal sulfides is considered one of the strategies to improve the electrochemical properties, by utilizing the synergistic effect of the individual metal sulfides components. Here, MnS@Bi 2 S 3 composites were obtained via three-step hydrothermal synthesized method. The MnS@Bi 2 S 3 composite exhibited superior electrochemical performance with specific capacitance 185 F g−1, compared to MnS (22 F g−1) and Bi 2 S 3 (45 F g−1) at current density 1 A g−1. Additionally, after 5000 cycles, MnS@Bi 2 S 3 exhibited superior capacitance retention of 92 % compared to 40 % and 73 % for MnS and Bi 2 S 3 , respectively. The superior performance of MnS@Bi 2 S 3 composite can be attributed to its higher specific surface area and the synergistic effect of MnS and Bi 2 S 3. • MnS@Bi 2 S 3 nanosheets composite was obtained by three-steps hydrothermal synthesis methods. • MnS@Bi 2 S 3 exhibits excellent electrochemical properties with high specific capacitance (185 Fg-1) and higher cycling performance (92 %) compared to MnS and Bi 2 S 3. • The microstructure of MnS@Bi 2 S 3 is in the form of loose and porous nanospheres, which improves the overall conductivity of the material. [ABSTRACT FROM AUTHOR]

The necessity to develop renewable energy resources that are highly durable and flexible with superior energy density and capacitance ability has attracted considerable interest in the field of solar cell research. Semiconducting compound materials that are easily available, hazard-free and cost-effective are emerging as potential solutions to tackle this challenge. Herein, we present multiple molecular precursors used to grow manganese sulfide nanoparticles through a proficient one-step heat-up approach. For all of the tested samples, the X-ray diffraction peaks correspond to a γ-MnS hexagonal wurtzite structure. UV-Vis spectroscopy yielded absorption wavelengths of 359–420 nm and band-gap energies of 3.78–4.0 eV. Photoluminescence analysis shows characteristics of red and blue shift from 451–602 nm. High-resolution transmission electron microscopy (HRTEM) and selected-area electron diffraction (SAED) reveal a narrow size distribution with nanosticks and large contact areas, which are critical for improved catalytic performance. The current study provides an improved pathway to a well-grown and uniform nanocrystal structure for applications in energy devices.

Nano MnS and ZnS samples are prepared through a simple thermolysis procedure. The effect of synthesis temperature on the different phases formed and their percentages, and on the lattice parameters and crystallite size of MnS and ZnS is examined using Rietveld analysis for X‐ray diffraction patterns. The minimum synthesis temperature at which MnS can be formed by the present simple procedure is 250 °C, while ZnS can be prepared at a lower temperature of 200 °C. For manganese sulfide, traces of Mn3O4 phase appear at 300 °C and increase with temperature, while ZnS resists oxidation until 500 °C; pure ZnO forms at 700 °C. The MnS and ZnS samples, obtained at all temperatures, are found to be biphasic; cubic and hexagonal. The nano nature of the samples and the particle morphology are investigated by high‐resolution transmission electron microscopy. Fourier‐transform infrared spectroscopy is applied to follow the characteristic vibration bands in both systems. The values of the different energy gaps depend on the crystallite size, phases' percentages, and the preparation temperature. The photoluminescence intensity and the emitted colors from MnS and ZnS depend on the synthesis temperature. [ABSTRACT FROM AUTHOR]

Hot compression tests of 3% Si steel with a true strain range of 0.02–0.92 at a strain rate of 1 s−1 and a temperature of 1173 K, based on the Gleeble‐1500 thermo–mechanical simulator, are conducted. The effect of strain on the strain‐induced precipitation behavior of MnS is investigated via cold field‐emission ultrahigh resolution scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The experimental results obtained indicate that the volume density of MnS precipitates increases, whereas the mean diameter of MnS precipitates decreases with the increase in strain during the transient deformation stage. However, during the steady deformation stage, these parameters remain nearly constant. The precipitation behavior of MnS during the transient deformation stage is attributed to the increase in dislocation density with the increase in strain. More dislocations create a larger number of nucleation sites, which, in turn, increase the nucleation rate. At the same time, a model about static recovery affecting the dislocation density in the matrix after deformation is also proposed to elucidate the mechanism of the evolution of MnS in the aging process. [ABSTRACT FROM AUTHOR]

Manganese sulfide nanospheres (MnS‐NSs) prepared in situ via sonochemical process were characterized to investigate the effect of nanoscale MnS on antifungal potential against mycopathogens of rice viz. Fusarium verticillioides, Drechslera oryzae and Curvularia lunata. MnS‐NSs dispersed in aqueous medium resulted in significant inhibition of growth of all the test fungi (ED50 ≤ 18 μg/ml) at concentration much lower than standard commercial fungicides (captan and carbendazim with ED50 ≥ 230 μg/ml) against respective fungi. The maximum per cent inhibition (98 ± 1.4) was recorded against C. lunata with a minimum ED50 value of 14 μg/ml, followed by D. oryzae and F. verticillioides with ED50 values of 17 and 18 μg/ml, respectively. Nanopriming of rice seeds with MnS‐NSs at 35 μg/ml for 8 hr resulted in significant reduction in seed rot (76%) and seedling blight (89.13%) along with enhancement in percent germination, root length, shoot length, dry weight and vigour index of seedlings by 33.7%, 55%, 66.3%, 85.3% and 89.3%, respectively, compared with control. Hydropriming of seeds was found to control the seed health parameters less effectively than nanopriming. [ABSTRACT FROM AUTHOR]

The process of brazing of different steel grades by pure liquid copper foil was studied to reveal the critical conditions when cracks do or do not appear in the braze upon cooling without any external load. Steel grades C45 (S 0.030 wt.%, no Mn and no Cr), S103 (Mn 0.25 wt.% and S 0.020 wt.% with no Cr), CK60 (0.75 wt.% Mn, 0.07 wt.% S and 0.15 wt.% Cr) and EN 1.4034 (Cr 12 wt.%, Mn 1.0 wt.% and S 0.035 wt.%) are studied under identical conditions using copper foils of 70-microns-thick. The samples were held above the melting point of copper at 1100 °C under high vacuum for different time durations (between 180 and 3600 s) and then cooled spontaneously. The joints were found cracked during cooling after a certain critical holding time. This critical holding time for cracking was found to decrease with increasing the Mn content and the S content of steel. It is observed that cracking is due to the precipitation of a critical amount of MnS phase upon cooling. The MnS/Cu interface is the weakest interface in the joint (with adhesion ensured only by van-der-Waals bonds), which is broken/separated upon cooling due to difference in heat expansion coefficients of the sulfide and copper phases. Higher is the Mn and S content, shorter is the probable time required for crack to appear in the joint. The braze integrity diagram is constructed as function of solubility product of MnS in steel and holding time showing a stable crack-free technological region and an unstable technological region with high probability of crack formation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Poly-cyclodextrin-coated manganese-dysprosium-sulfide and manganese sulfide nanoparticles are synthesized. • Manganese and dysprosium sulfide nanocomposite displays a crystallinity index of 95.18%. • Manganese-dysprosium sulfide nanoparticles demonstrate weak saturation magnetization. • 5-Fluorouracil is released sustained from the nanoparticles and it is pH-dependent. • The 5-fluorouracil-loaded Mn-Dy-sulfide nanoparticles exhibit a low IC 50 of 7.9 ± 0.5 μg mL−1 on MCF-7 cells. Sulfide nanoparticles are an intriguing class of nanomaterials, employed in various biomedical applications including cancer diagnosis and treatment. The current study explores the multifaceted characteristics and potential applications of poly-β-cyclodextrin (poly-CD)-coated manganese-dysprosium-sulfide (Mn-Dy-sulfide) and manganese sulfide nanoparticles. The Mn-Dy-sulfide nanoparticles exhibit an average crystallite size of 21.97 nm, signifying their nanoscale nature. In terms of magnetic properties, these nanoparticles demonstrate weak saturation magnetization values and positive magnetic susceptibility, with a notable M S of 0.6019 emu/g and a coercivity value of 277.95 Oe for the poly-CD coated Mn-Dy-sulfide nanoparticles. Moreover, these nanoparticles serve as effective drug carriers, with drug loading contents of 7.35 % and an impressive drug encapsulation efficiency of 77.93 %. Their drug release profile reveals approximately 50 % drug release at around 110 h (pH 7.4) and 160 h (pH 6.0), offering controlled drug delivery capabilities. Crucially, the anticancer activity of these nanoparticles is evident in their IC 50 values. Mn-Dy-sulfide nanoparticles loaded with 5-fluorouracil exhibit a low half-maximal inhibitory concentration (IC 50) of 7.9 ± 0.5 μg mL−1, demonstrating their potential as effective anticancer agents. Precisely, these poly-CD coated Mn-Dy-sulfide nanoparticles exhibit exceptional characteristics, including nanoscale size, high crystallinity, magnetic responsiveness, optical properties, drug delivery capabilities, and potent anticancer activity. [ABSTRACT FROM AUTHOR]

Precipitation of MnS inclusions in steel affects the mechanical properties of the material significantly. The evolution of MnS inclusions along the continuous casting slab thickness and its influencing factors has not been clearly established and comprehensively studied. In this paper, solidification macrostructure, sulfur segregation and MnS inclusions in the continuous casting slab of medium carbon structural steel 45# were studied by various methods, including the metallographic observations, elemental analysis, scanning electron microscope (SEM) with Energy Dispersive Spectrometer (EDS) observation, automatic particle analysis, and thermodynamic calculations. The 2D/3D morphologies of MnS inclusions suggest that the sulfides turn from globular to rodlike, and further to dendritic shape along the slab thickness progressively. Furthermore, it was found that MnS inclusions are remarkably aggregated in the columnar crystals and the equiaxed crystals mixed zone, where the sulfides have the largest average diameter of 6.35 μm and the second maximum area fraction of 0.025% along the slab thickness. In order to reveal the mechanism of this phenomenon, the precipitation temperature of MnS inclusion in the 45# steel was clarified by thermodynamic calculation and experimental observation, and the quantitative relationships among the distribution of sulfur content, secondary dendrite arm spacing (SDAS), and precipitation area fraction of MnS inclusions were discussed. Moreover, the inclusion size was numerically predicted to compare with the measured value. The results indicate that the large SDAS, high sulfur content and low cooling rate accounting for the large-size aggregated MnS inclusions in the mixed zone. Unfortunately, the dendritic MnS inclusions, even if the average diameter exceeds 52 μm, can act as the nucleation sites for ferrites, and the distribution of the sulfides promotes uneven microstructure in the steel.

In most steels, tin (Sn) is a tramp element due to its hot shortness at grain boundaries and the surface, although Sn also has a vital influence on free-cutting steel, electrical sheets, cast iron, and stainless steel. If the problem of hot shortness is solved, scrap recycling will become much easier and Sn can even be used as an important alloying element. As such, it is most important to investigate the forms of Sn precipitation in C-Mn steels at high temperatures. In this study, Fe-5% Sn and Fe-1.5% Sn-0.2% S steels were investigated to clarify the types of Sn precipitates. The morphology, size, and structure of Sn precipitates were characterized by scanning electron microscopy with energy dispersive spectroscopy and transmission electron microscopy. The influence of heat treatment temperature on the type of Sn precipitates was also investigated. The results show that Sn-riched particles precipitate at grain boundaries and in grains in Fe-5% Sn steels, whereas in Fe-1.5% Sn-0.2% S steels, heterogeneous Sn particles precipitate in the size of spherical MnS inclusions with diameters ranging between 2-4 μm. The transmission electron microscopy analysis and heat treatment experimental results show a FeSn2 structure with a tetragonal system for Sn precipitates in Fe-5% Sn and Fe-1.5% Sn-0.2% S steels.

The crystallographic, optical, and electrical properties of manganese sulfide thin films depend on the control of the temperature precursors in the synthesis process, as shown by the results of this work. MnS thin films were deposited on glass substrates using the SILAR method and over an additional layer of CdS synthesized by chemical bath deposition (CBD) to acquire a p-n heterojunction. SILAR is an inexpensive method performed with a homemade robot in this case. Temperature in the solution precursors varied from 20 to 80 °C in four experiments. The morphology and structure of MnS and FTO/CdS/MnS thin films were studied through scanning electron microscopy (SEM) and grazing-incidence X-ray diffraction (GIXRD); the results indicate that materials showed a polycrystalline behavior, a diffraction peak of α - MnS cubic phase was observed with lattice constants values, ranging from 4.74 to 4.75 Å. Additionally, Raman spectroscopy showed a signal corresponding to the transversal optical phonons of MnS at a wavenumber near 300 cm -1 . UV-vis spectroscopy showed optical bandgap values of 3.94, 4.0, 4.09, and 4.26 eV for thin films obtained at 20°, 40°, 60°, and 80 °C. respectively. Results indicated 80 °C as an optimal cationic precursor process temperature, achieving optical transmittance T% and good film quality according to SEM and GIXRD for the synthetization of MnS. The current-voltage (I-V) characterization in the heterojunction showed a characteristic diode curve with an open circuit voltage (VOC) of 300 mV under illumination, which indicated that the manganese sulfide behaves as p-type material contributing with positive charge carriers, while CdS behaves as n-type material., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

Photocatalytic hydrogen production from hydrogen sulfide (H 2 S) splitting has been considered as an appealing and sustainable approach to resolve both energy crisis and environment problem. It remains challenging to quest suitable photocatalysts for highly efficient H 2 S splitting. Herein, a series of graphene oxide (GO)/MnS-Mn 3 O 4 composites were successfully prepared via a mild method. The results demonstrated that the GO plays three roles in enhancing the photocatalytic H 2 S splitting performance (i) enhancing sunlight response, (ii) promoting electrons transfer, (iii) inducing manganese oxide specie (Mn 3 O 4) in-situ produced for hole trapping. As a result, the GO/MnS-Mn 3 O 4 composites exhibit enhanced visible-light photocatalytic H 2 S splitting activity, which is 6 folds higher than that of bare MnS. Finally, the photocatalytic mechanism is proposed over GO/MnS-Mn 3 O 4 composites. This work provides a facile strategy for fabricating double cocatalyst on metal sulfides to realize improved photocatalytic H 2 S splitting activity. Constructing GO/MnS-Mn 3 O 4 dual cocatalysts system via GO-induced strategy for enhancing photocatalytic hydrogen production from hydrogen sulfide. Unlabelled Image • The GO/MnS-Mn 3 O 4 dual cocatalysts system was successfully constructed by a mild approach. • GO/MnS-Mn 3 O 4 showed enhanced carrier separation by the synergistic effect of GO and Mn 3 O 4. • The formation of C-O-Mn bond is favorable for further inhibiting the carrier recombination. • The optimized GO/MnS-Mn 3 O 4 exhibited 6 times higher H 2 evolution rate than pure MnS. (λ > 420 nm). [ABSTRACT FROM AUTHOR]

The oxidation state studies of Mn 1-x Ln x S (Ln = Dy, Tm, Yb; x = 0; 0.01; 0.05) solid solutions was carried out for the first time using X-ray photoelectron and emission spectroscopy. The binding energy of the S(2 p)-, Ln(4 d)-, multiplet splitting analysis of Mn(3 s)-level and the S K α 1 -line energy position allow one to determine atoms oxidation state. The lanthanide atoms were found to be in the trivalent, while the manganese and sulfur atoms were in the divalent state. The near-surface layers contain sulfur atoms in the 0, +4 and +6 oxidation states. The obtained data on the oxidation state were compared with those in lanthanide sulfides Ln 2 S 3 (Ln = Dy, Tm, Yb). The additional 4f -electrons emerged after cationic substitution are assumed to be delocalized in the conduction band and affect physical properties of doped manganese monosulfide. The oxidation state of lanthanide and manganese atoms both on the surface and in the bulk was found to be the same in the compounds studied. The surface layer doesn't contain an additional metal oxidation states (magnetic scattering centers) that significantly affect the colossal magnetoresistance. • Oxidation state study of Mn 1-x Ln x S was carried out using XPS and XES. • The lanthanide atoms in the bulk are +3, the Mn and S atoms are in divalent state. • The S atoms on the samples surface give an significant contributions in the S(2 p)-region. [ABSTRACT FROM AUTHOR]

Energy density and power density are two key parameters of the supercapacitor. Selecting suitable positive electrode materials and negative electrode materials to construct asymmetric supercapacitor is an effective way to improve energy density. Here, a novel asymmetric supercapacitor was assembled by using α-Fe2O3/rGO nanocomposites as negative electrode and α-MnS/rGO nanocomposites as positive electrode. The fabricated α-MnS/rGO//α-Fe2O3/rGO asymmetric supercapacitors (ASCs) showed a largest potential window of 1.6 V when 3 M KOH was used as electrolyte. The ASCs displayed a maximum specific capacitance of 161.7 F g−1 at a current density of 1 A g−1, and the highest energy density of 57.5 Wh kg−1 at the power density of 800 W kg−1. These encouraging performances of the α-MnS/rGO//α-Fe2O3/rGO ASCs shed light on the use of α-Fe2O3/rGO nanocomposites and α-MnS/rGO nanocomposites as promising candidate materials for asymmetric supercapacitor applications. [ABSTRACT FROM AUTHOR]

Although transition metal sulfides have gotten extensive attention due to their high electrical conductivity, fast charge transfer kinetics, outstanding mechanical stability, the performances of them applied separately to supercapacitors are not satisfactory, and one solution is to hybridize with other metal sulfide materials. Therefore, in the study, the flower-like structure Cu-Mn bimetallic sulfide on Ni-foam (CuS/MnS@NF) was firstly synthesized by a hierarchical two-step solvothermal reaction to our knowledge, which was directly utilized as electrodes without binders or conductive agents. The CuS/MnS@NF electrode possesses flower-like morphology, superior electrical conductivity, and there are the synergistic effect and intense interaction between CuS and MnS. They can display higher specific capacitance of 1517.07 F g−1 at 1 A g−1 and excellent cyclic stability with specific capacity retention of 115.6% at 10 A g−1 after 3000 cycles, which is more admirable than their individual metal sulfide electrodes (CuS@NF and MnS@NF) and other recently reported metal-based electrodes. In short, the CuS/MnS@NF electrodes are promising candidate when used in battery-type supercapacitors. Image 1 • The CuS/MnS@NF electrodes were firstly synthesized by a hierarchical two-step solvothermal synthesis. • The CuS/MnS@NF electrodes display higher specific capacitance and excellent cyclic stability. • The CuS/MnS@NF electrodes possess flower-like morphology and superior electrical conductivity. • There is the synergistic effect and an intense interaction between CuS and MnS in CuS/MnS@NF. [ABSTRACT FROM AUTHOR]

With high power density and promising possibilities for high energy density, the electrochemical capacitor has become an indispensable energy storage device to satisfy the future energy demands. Here in, we report on synthesis of graphene nanosheets (GNS) supported manganese sulfide (MnS) hybrid (GNS-MnS) nanocomposite by a simple, facile hydrothermal process. The resultant GNS-MnS hybrid nanocomposite with robust electronic amalgamation facilitates swift transfer of both ions and electrons across the interface between electrode surface and electrolyte ions than pristine MnS. Benefiting from the better conduction along with improved active sites of the MnS in GNS-MnS hybrid nanocomposite, a high ratio surface/near-surface reactions is dominated by high specific capacity even at high current rate. As such, the GNS-MnS hybrid nanocomposite exhibited a maximum specific capacitance of 792 F g−1 at 2 A g−1 along with better retention rate of 58% at 15 A g−1, is significantly higher than that of pristine MnS (423 F g−1 at 2 A g−1 and 37% retention at 15 A g−1). In addition, the fabricated symmetric GNS-MnS hybrid nanocomposite cell delivered a high energy density of 25 W h kg−1 and power density of 7160 W kg−1. Moreover, specific capacitance of 91.1% is retained after 15000th cycles with columbic efficiency of ∼100% at 20 A g−1. The remarkable electrochemical performance of GNS-MnS hybrid nanocomposite electrode demonstrated its potential as a key material for developing high energy supercapacitors. Image 1 • Facile synthesis of graphene nanosheets - manganese sulfide (GNS – MnS) hybrid nanocomposite by a simple hydrothermal method. • GNS - MnS hybrid nanocomposite exhibited a maximum specific capacitance of 792 F g−1 at 2 A g−1 than the pristine MnS. • GNS-MnS hybrid nanocomposite symmetric cell delivered a high energy density of 25 W h kg−1and power density of 7.16 kW kg−1. • The symmetric cell showed ∼91% electrochemical stability for 15,000 cycles. [ABSTRACT FROM AUTHOR]

Self-powered energy devices are essential devices for application in future portable electronics. The self-powered applications of photo-supercapacitors (PSCs), as dependable energy harvesting devices, have been investigated using the photovoltaic effect of supercapacitors. In this work, a simple electrodeposition method has been used to successfully prepare novel, flower-like MnS@V 2 O 5 -BiVO 4. Different analytical methods have been used to study the phase composition, morphology, and photoelectrochemical properties of the prepared samples. The best MnS@V 2 O 5 -BiVO 4 electrode (sample S1) showed a high average 41.6 F/g specific capacitance at a current density of 10 µA/cm2, which is 7.5 times the equivalent value for the bare V 2 O 5 -BiVO 4 electrodes. An improved photocurrent density of 115 µA/cm2 was also shown by this sample after 1 cycle of MnS deposition, which is about 3.3 times higher than the corresponding value for the bare sample. The poor electron-hole separation of bare samples can be overcome by the improved photocurrent density. The effect of light illumination on charge storage performance was investigated by different electrochemical techniques in the dark and under light illumination. The best MnS@V 2 O 5 -BiVO 4 electrode synthesized, sample S1, showed real capacitance values of 10 and 6.3 F/g (@20 mV/s) and 41.6 and 6.3 F/g (@10 μA/cm2) prior to and following light illumination, respectively, due to the extension of the discharge time by the charge carriers produced under light excitation and contribution of excess generated electron-hole pairs to the charge storage. In addition, a symmetric supercapacitor has been prepared using the best MnS@V 2 O 5 -BiVO 4 with a maximum energy density of 7.0 Wh/kg at a 250 W/kg power density (@0.1 mA/cm2) and stable capacitance retention after 3000 cycles. In addition, the best MnS@V 2 O 5 -BiVO 4 electrode and MnS/graphite asymmetric supercapacitors have been prepared with 3.0 × 3.0 cm2 dimensions. The device is charged under light irradiation and can easily turn on LED light, which indicates its potential practical applications as an appealing energy storage device. The remarkable performance makes MnS@V 2 O 5 -BiVO 4 a promising compound for energy storage purposes. • MnS@V 2 O 5 -BiVO 4 electrodes were prepared via electrodeposition. • A 6.6-fold increase in the charge storage on light were observed. • The charged photo-supercapacitor under light can turn on LED light. [ABSTRACT FROM AUTHOR]

In-situ observation of the behavior of MnS inclusions in non-quenched and tempered steel with a sulfur mass fraction of 0.065% was performed during tensile tests by using a laser confocal scanning microscope (LCSM) to investigate the effects of the morphology and distribution of MnS inclusions on the tensile property anisotropy of the steel. The result shows that there exist a large number of rod-like MnS inclusions in the forged steel, which have different orientations with the load during transverse and longitudinal tensile tests. The rod-like MnS inclusions separate much easier from the steel base during transverse tensile tests to form initial cracks, and then the cracks spread along the MnS inclusions. In this way, the cracks grow up and lead to the fracture of the steel. In contrast, the MnS inclusions have little effects on the longitudinal tensile properties because the length direction of MnS is parallel to the tensile force. MnS inclusion aggregation promotes the assembling and growth of single cracks, thus accelerating the fracture of the steel during tensile tests.

We investigated how the outcome of the solvothermal synthesis of manganese(II) sulfide (MnS) nanocrystals (NCs) is affected by the type and amount of long chain surfactant present in the reaction mixture. Prompted by a previous observation that a larger than stoichiometric amount of sulfur is required [Puglisi, A.; Mondini, S.; Cenedese, S.; Ferretti, A. M.; Santo, N.; Ponti A. Chem. Mater. 2010, 22, 2804–2813], we carried out a wide set of reactions using Mn(II) carboxylates and Mn2(CO)10 as precursors with varying amounts of sulfur and carboxylic acid. MnS NCs were obtained provided that the S/Mn ratio was larger than the L/Mn ratio, otherwise MnO NCs were produced. Since MnS can crystallize in three distinct phases (rock salt α-MnS, zincblende β-MnS, and wurtzite γ-MnS), we also investigated whether the surfactant affected the NC polymorphism. We found that MnS polymorphism can be controlled by appropriate selection of the surfactant. γ-MnS nanocrystals formed when a 1:2 mixture of long chain carboxylic acid and amine was used, irrespective of the presence of carboxylic acid as a free surfactant or ligand in the metal precursor. When we used a single surfactant (carboxylic acid, alcohol, thiol, amine), α-MnS nanocrystals were obtained. The peculiar role of the amine seems to be related to its basicity. The nanocrystals were characterized by TEM and electron diffraction; ATR-FTIR spectroscopy provided information about the surfactants adsorbed on the NCs.

The morphology, size, composition, and number of inclusions in pipeline steel were characterized by scanning electron microscopy and energy dispersive spectroscopy. The characteristics of the inclusions with different Ti/Mg ratios as well as the influence of sulfur content and the number of deoxidation products on the precipitation behavior of MnS were investigated, and the corresponding thermodynamic calculations were carried out. It is found that the core of the inclusions is mainly composed of MgO-Al2O3-Ti2O3, MgO-Ti2O3 or MgO, and then MnS wraps or locally precipitates on them. The inclusions have the average size smaller than 1.3 txm and the number of 300 to 450 mm-2; moreover, their morphology is diverse such as round, polygonal and square. When the Ti/Mg atomic ratio is 0.05 to 0.2, the inclusions are round and small. With the decrease of sulfur content, MnS less tends to precipitate during solidification, its ways of precipitation on the inclusion surface will change from wrapped to local precipitated. A great number of oxides is conducive to the heterogeneous nucleation of more finely MnS on the surface of complex oxides. The Ti-Mg complex deoxidation products are small and dispersed, can become the heterogeneous nucleation core of MnS, and may reduce the harm of MnS and oxides at the same time.

Improving the adsorption selectivity, enhancing the extraction capacity, and ensuring the structural stability of the adsorbent are the key to realize the high efficiency recovery of uranium. In this work, we utilized the strong Lewis acid-base interaction between S 2- and U(VI)O 2 2+ coupling rapid electron transfer at the MnS/U(VI)O 2 2+ solid-liquid interface to achieve excellent selectivity, high adsorption capacity, and rapid extraction of uranium. The as-synthesized MnS adsorbent exhibited an ultrahigh uranium extraction capacity (2457.05 mg g -1 ) and a rapid rate constant ( K = 9.11 × 10 -4 g h -1 mg -1 ) in seawater with 100.7 ppm of UO 2 (NO 3 ) 2 electrolyte. The kinetic simulation reveals that this adsorption process is a chemical adsorption process and conforms to a pseudo-second-order kinetic model, indicating electron transfer at the MnS/U(VI)O 2 2+ solid-liquid interface. The relevant (quasi) in situ spectroscopic characterization and theoretical calculation results further revealed that the outstanding uranium extraction property of MnS could be attributed to the highly selective UO 2 2+ adsorption of MnS with lower adsorption energy as a result of the strong interaction between S 2- and UO 2 2+ and the rapid mass transfer and interface electron transfer from S 2- and low-valent Mn(II) to U(VI)O 2 2+ .

Lead sulfide (PbS)/manganese sulfide (MnS) heterojunction is synthesized by a simple two-step chemical bath deposition technique. The as-synthesized heterojunction is studied based on the optical and electrical analyses. The optical absorbance spectrum of the test structure confirms dual peaks at two different wavelengths, which has prompted consideration of the two band gaps of the structure. The origin of dual peaks in the absorbance plot is attributed to the existence of the PbS base layer and the MnS window layer. The band gaps are estimated using the conventional Tauc's method (Eg = 1.75 eV and 2.9 eV) and also by the absorbance spectrum fitting method (Eg = 1.82 eV and 2.97 eV). In the dc analyses, the PbS/MnS heterojunction possesses low dark current and high dynamic resistance. However, under illumination (400-700 nm) a distinct photo-response is observed, showing a substantial rise in device current with the reduction of dynamic resistance. The photo-response of the heterojunction is examined at 635-699 nm, 514-538 nm and 410-452 nm wavelengths by analyzing the photo-current and photo-resistance. The device is found to be more photosensitive at lower wavelength illuminations compared to the higher wavelength exposures. [ABSTRACT FROM AUTHOR]

Abstract A comprehensive study of the valence state and the local coordination character of Mn 1−x Yb x S (x = 0; 0.01; 0.05) solid solutions has been performed using X-ray absorption spectroscopy combined with finite difference method calculations. The good agreement between experimental and calculated data indicates that cationic substitution does not lead to significant changes in the manganese local coordination character. The ytterbium atoms are found to be in the trivalent state, while the manganese and sulfur atoms are in the divalent state. Graphical Abstract According to the experimental and calculated data, the ytterbium atoms are in the trivalent state, the manganese and sulfur atoms are in divalent state in the cation-substituted solid solutions Mn 1−x Yb x S (x = 0; 0.01; 0.05). Unlabelled Image Highlights • Charge state studies of Mn 1−x Yb x S performed using XANES, XES and quantum chemistry. • The Yb atoms are in the trivalent state, the Mn and S atoms are in divalent state. • The Mn → Yb substitution does not changes the local environment structure of Mn. [ABSTRACT FROM AUTHOR]