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The oxygen evolution reaction (OER), which has slow kinetics and low economic value of the product, seriously reduces the energy conversion efficiency of the overall water electrolysis for hydrogen production and the economic benefits of its practical applications. Therefore, replacing OER with an oxidation reaction that has a lower potential and higher value can effectively reduce the cell voltage and energy consumption for hydrogen production, improve the energy conversion efficiency, and at the same time obtain high-value-added chemical products. This paper establishes a new low-energy-consumption water electrolysis for hydrogen production coupling system based on the oxidative azo coupling reaction of 3,4-diaminofurazan. The specific method is to use a carbon cloth-supported NiS2 catalyst (CC@NiS2) as the cathode hydrogen evolution reaction catalyst and utilize a copper oxide nanocatalyst to drive the anode reaction, thereby constructing the entire coupling system and conducting relevant experimental tests and analyses. This system only requires a cell voltage of 1.45 V to drive a current density of 10 mA cm-2, which is 330 mV lower than that of the traditional water electrolysis system (1.78 V). Among them, the carbon cloth-supported NiS2 catalyst as the cathode hydrogen evolution reaction catalyst can stably operate for more than 20 hours with an overpotential of only 190.5 mV when driving a current density of 10 mA cm-2. Meanwhile, the anode can achieve the electrosynthesis of 3,3'-diamino-4,4'-azofurazan energetic materials. Driven by the copper oxide nanocatalyst, problems such as high danger, high pollution, and high cost that occur in conventional organic synthesis are avoided. This paper provides a new strategy for the safe production of energetic organic compounds and the low-energy-consumption and green preparation of high-purity hydrogen. [ABSTRACT FROM AUTHOR]

Transition metal sulfides as anode materials for sodium‐ion batteries (SIBs) have the advantage of high capacity. However, their cycle‐life and rate performance at ultra‐high current density is still a thorny issue that limit the applicability of these materials. In this paper, the carbon‐embedded heterojunction with sulfur‐vacancies regulated by ultrafine bimetallic sulfides (vacancy‐CoS2/FeS2@C) with robust interfacial C‐S‐Co/Fe chemical bonds is successfully synthesized and explored as an anode material for sodium‐ion battery. By changing the ratio of two metal cations, the concentration of anion sulfur vacancies can be in‐situ adjusted without additional post‐treatment. The as‐prepared vacancy‐CoS2/FeS2@C anode material offers ultrahigh rate performance (285.1 mAh g−1 at 200 A g−1), and excellent long‐cycle stability (389.2 mAh g−1 at 40 A g−1 after 10000 cycles), outperforming all reported transition metal sulfides‐based anode materials for SIBs. Both in‐situ and ex‐situ characterizations provide strong evidence for the evolution mechanism of the phases and stable solid‐electrolyte interface (SEI) on the vacancy‐CoS2/FeS2@C surface. The density functional theory calculations show that constructing heterojunction with reasonable concentration of vacancies can significantly increase the anode electronic conductivity. Notably, the assembled vacancy‐CoS2/FeS2@C//Na3V2(PO4)3/C full‐cell shows a capacity of 226.2 mAh g−1 after 400 cycles at 2.0 A g−1, confirming this material's practicability. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hierarchical core-shelled CoMo-LDH@CuCo 2 S 4 NWAs/NF is prepared by hydrothermal synthesis and electrodeposition. • The electrode exhibits a high specific capacity of 1265.9 C g−1 at 1 A g−1. • The electrode shows a 92.2% capacity retention ratio at 10 A g−1 after 10, 000 cycles. • The energy density of the assembled HSC device is 52.2 Wh kg−1 at the power density of 983.9 W kg−1. The development of core-shelled heterostructures with the unique morphology can improve the electrochemical properties of hybrid supercapacitors (HSC). Here, CuCo 2 S 4 nanowire arrays (NWAs) are vertically grown on nickel foam (NF) utilizing hydrothermal synthesis. Then, CoMo-LDH nanosheets are uniformly deposited on the CuCo 2 S 4 NWAs by electrodeposition to obtain the CoMo-LDH@CuCo 2 S 4 NWAs/NF electrode. Due to the superior conductivity of CuCo 2 S 4 (core) and good redox activity of CoMo-LDH (shell), the electrode shows excellent electrochemical properties. The electrode's specific capacity is 1271.4 C g−1 at 1 A g−1, and after 10, 000 cycles, its capacity retention ratio is 92.2 % at 10 A g−1. At a power density of 983.9 W kg−1, the CoMo-LDH@CuCo 2 S 4 NWAs/NF//AC/NF device has an energy density of 52.2 Wh kg−1. This indicates that CoMo-LDH@CuCo 2 S 4 /NF has a great potential for supercapacitors. [ABSTRACT FROM AUTHOR]

The controlled formation and stabilization of nanoparticles is of fundamental relevance for materials science and key to many modern technologies. Common synthetic strategies to arrest growth at small sizes and prevent undesired particle agglomeration often rely on the use of organic additives and require non-aqueous media and/or high temperatures, all of which appear critical with respect to production costs, safety, and sustainability. In the present work, we demonstrate a simple one-pot process in water under ambient conditions that can produce particles of various transition metal carbonates and sulfides with sizes of only a few nanometers embedded in a silica shell, similar to particles derived from more elaborate synthesis routes, like the sol–gel process. To this end, solutions of soluble salts of metal cations (e.g., chlorides) and the respective anions (e.g., sodium carbonate or sulfide) are mixed in the presence of different amounts of sodium silicate at elevated pH levels. Upon mixing, metal carbonate/sulfide particles nucleate, and their subsequent growth causes a sensible decrease of pH in the vicinity. Dissolved silicate species respond to this local acidification by condensation reactions, which eventually lead to the formation of amorphous silica layers that encapsulate the metal carbonate/sulfide cores and, thus, effectively inhibit any further growth. The as-obtained carbonate nanodots can readily be converted into the corresponding metal oxides by secondary thermal treatment, during which their nanometric size is maintained. Although the described method clearly requires optimization towards actual applications, the results of this study highlight the potential of bottom-up self-assembly for the synthesis of functional nanoparticles at mild conditions. [ABSTRACT FROM AUTHOR]

To realize the practical application of rechargeable Zn–Air batteries (ZABs), it is imperative to develop a non‐noble metal‐based electrocatalyst with high electrochemical performance for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Herein, Ni‐doped Co9S8 nanoparticles dispersed on an inverse opal‐structured N, S co‐doped carbon matrix (IO─NixCo9‐xS8@NSC) as a bifunctional electrocatalyst is presented. The unique 3D porous structure, arranged in an inverse opal pattern, provides a large active surface area. Also, the conductive carbon substrate ensures the homogeneous dispersion of NixCo9‐xS8 nanocrystals, preventing aggregation and increasing the exposure of active sites. The introduction of heteroatom dopants into the Co9S8 structure generates defect sites and enhances surface polarity, thereby improving electrocatalytic performance in alkaline solutions. Consequently, the IO─NixCo9‐xS8@NSC shows excellent bifunctional activity with a high half‐wave potential of 0.926 V for ORR and a low overpotential of 289 mV at 10 mA cm−2 for OER. Moreover, the rechargeable ZAB assembled with prepared electrocatalyst exhibits a higher specific capacity (768 mAh gZn−1), peak power density (180.2 mW cm−2), and outstanding stability (over 160 h) compared to precious metal‐based electrocatalyst. [ABSTRACT FROM AUTHOR]

Transition metal sulfides have garnered significant attention due to their distinctive properties, including electrical, optical, catalytic, and magnetic capabilities, and their potential for use in various applications. The present work discloses the fabrication of CuxMn1-xS (X = 0, 0.5, and 1) nanoparticles (NPs) using the co-precipitation method. The powder X-ray diffraction (PXRD) technique was utilized to characterize the synthesized sample, confirming that it exhibits cubic and hexagonal crystal structures. The Debye-Scherrer formula was applied to determine the average crystallite size of the nanoparticles, while the Williamson–Hall plot was employed to estimate microstrain and particle size. Energy-dispersive X-ray spectroscopy (EDAX) analysis revealed that Cu, Mn, and S were present in the nanoparticles without any impurities. Field Emission Scanning Electron Microscopy (FESEM) was used to determine the material's morphology and effective grain size. UV-vis spectroscopy was employed to measure the optical properties of the sample. The optical bandgap, calculated from the Tauc plot, ranged from 1.6 to 2.8 eV, indicating the presence of photovoltaic properties in the sample. The dielectric constant and loss were observed to change for the sample in the frequency range of 10 KHz to 2 MHz at room temperature. The frequency-dependent electrical conductivity, impedance, and modulus spectroscopy of CuxMn1-xS were also analyzed. The dielectric study results showed that increasing frequency decreases the dielectric constant and dielectric loss. Additionally, MnS, CuS, and CuMnS NPs were screened for their antibacterial activity against gram-negative (-ve) pathogenic bacteria. Among them, CuMnS exhibited the maximum antibacterial activity against Salmonella typhi and Salmonella paratyphi A pathogens. Highlights: CuxMn1-xS nanoparticles were manufactured by co-precipitation approach. The fabricated CuxMn1-xS nanoparticles were analyzed via UV, PXRD, SEM, and EDAX analyses. The structural and optoelectronic properties of the fabricated CuxMn1-xS nanoparticles were studied. The antibacterial performance of the fabricated CuxMn1-xS nanoparticles was tested. [ABSTRACT FROM AUTHOR]

Abstract Rechargeable aluminum-ion batteries (AIBs) stand out as a potential cornerstone for future battery technology, thanks to the widespread availability, affordability, and high charge capacity of aluminum. However, the efficacy of current AIBs on the market is significantly limited by the charge storage process within their graphite cathodes. To fully realize the capabilities of AIBs, the discovery of a new cathode material is essential. Transition metal sulfides present an attractive option for cathode materials, although there has been a variety of conflicting reports regarding the exact nature of their charge storage mechanisms. This paper investigates cobalt sulfide (CoSx) cathodes in AIBs, with a particular focus on deciphering the mechanisms of charge storage. Through synthesis, electrochemical testing, and post-cycling characterization, we illuminate the roles of AlCl4 − intercalation, cobalt sulfide to Al2S3 conversion, and sulfur to Al2S3 conversion in charge storage. As cycling progresses, Al2S3 synthesis from segregated sulfur segments emerged as the predominant mechanism, showcasing its potential to fully leverage the high capacity of aluminum metal and propel AIBs towards higher energy densities. Despite these promising findings, the study also uncovered significant challenges, notably material loss, intra-cathode diffusion limitations, and irreversible reactions that precipitously diminish charge capacity over time. These issues highlight the critical need for enhanced electrode stability, improved electrolyte compatibility, and accelerated aluminum diffusion. The research paves the way for further exploration of transition metal sulfides as cathode materials in AIBs, highlighting the imperative for innovations that bolster mechanical and chemical stability while optimizing ion transport. This work not only contributes to the fundamental understanding of charge storage in AIBs but also charts a course for the development of more durable and efficient battery systems.

The chemical engineering community has shown significant interest in investigating methods to decompose hydrogen sulfide into hydrogen and sulfur. However, there is still a lack of detailed experimental data enabling us to choose the optimal catalyst, reaction, and regeneration conditions, as well as the overall process design. The purpose of this work is to synthesize a series of catalysts and compare their catalytic activity under the same conditions, chosen on the basis of a possible large-scale H2S conversion process. To achieve this, the obtained catalysts were characterized by BET, XRD, SEM, TEM, and XPS before and after the reaction. Decomposition was conducted in a laboratory fixed-bed reactor at a temperature of 500 °C, 10 vol% of H2S in the feed, and a GHSV of 540–1000 h−1. DFT calculations evaluated the H2S bond cleavage on various catalyst surfaces. It was shown that the most promising catalyst was Ni3S2, offering an acceptable H2S conversion of 40%. We also observed that Ni3S2 catalyst regeneration could be conducted at much milder conditions compared to those previously reported in the literature. These results highlight the viability of upscaling the process with the selected catalyst. [ABSTRACT FROM AUTHOR]

Transition metal sulfides (TMS) exhibit significant promise as non‐noble‐metal electrocatalysts for the oxygen evolution reaction (OER) in alkaline environments, notwithstanding their susceptibility to long‐term instability due to the gradual leaching of surface‐reconstructed sulfate ions (SO42−). In this study, a sulfate ion‐assisted strategy is proposed to stabilize the surface‐reconstructed SO42− of FeNiS2. The findings reveal that SO42− experiences considerable loss in KOH due to the infinite concentration gradient of SO42− on the surface. Conversely, in K2SO4/KOH, this strategy mitigates rapid leaching and preserves the predominant surface‐reconstructed SO42−, thereby enhancing stability in both accelerated degradation (5000 cycles) and long‐term (≥120 h) tests, with ≈95% current density retained. Furthermore, the optimal concentration of SO42− proves to be crucial, as supported by both experimental and theoretical results. This approach offers insights into bolstering the long‐term OER stability of TMS and similar compounds, thereby advancing the prospects for widespread application in electrocatalytic water splitting. [ABSTRACT FROM AUTHOR]

Additive manufacturing of transition metal sulfides (TMS) enables the creation of complex 3D structures, significantly expanding their applications. However, preparing 3D‐structured TMS remains challenging due to difficulties in developing suitable inks. In this study, a supramolecular micelle hydrogel as the ink to fabricate 3D‐structured TMS is utilized. Initially, the hydrogels are printed and infused with metal salt solutions to stabilize the structures, which are then calcined to convert into miniaturized 3D‐TMS replicas. The micellar hydrogels crosslink via hydrophobic interactions, with sodium dodecyl sulfonate (SDS) micelles providing both a hydrophobic environment and sulfur sources. During calcination, the decomposed sulfur precursors coordinate with metal ions to form various TMS, including FeS2, Cu2S, Ni3S2, and Co9S8, along with several metal sulfides like PbS and SnS. Additionally, the method also allows for the preparation of transition metal dichalcogenides such as MoS2 and WS2. The formation mechanism is demonstrated using Ni3S2 as an example which exhibits notable catalytic activity in oxygen evolution reactions (OER) and hydrogen evolution reactions (HER). Given its simplicity and versatility, this dynamic micellar hydrogel‐derived strategy offers a promising pathway for creating advanced TMS materials. [ABSTRACT FROM AUTHOR]

The reactivity of nitrogen oxide, NO, as a ligand in complexes with [Fe2-S2] and [Co2-S2] non-planar rhombic cores is examined by density functional theory (DFT). The cobalt-containing nitrosyl complexes are less stable than the iron complexes because the Co-S bonds in the [Co2-S2] core are weakened upon NO coordination. Various positions of NO were examined, including its binding to sulfur centers. The release of NO molecules can be monitored photochemically. The ability of NO to form a (NO)2 dimer provides a favorable route of electrochemical reduction, as protonation significantly stabilizes the dimeric species over the monomers. The quasilinear dimer ONNO, with trans-orientation of oxygen atoms, gains higher stability under protonation and reduction via proton–electron transfer. The first two reduction steps lead to an N2O intermediate, whose reduction is more energy demanding: in the two latter reaction steps the highest energy barrier for Co2S2(CO)6 is 109 kJ mol−1, and for Fe2S2(CO)6, it is 133 kJ mol−1. Again, the presence of favorable light absorption bands allows for a photochemical route to overcome these energy barriers. All elementary steps are exothermic, and the final products are molecular nitrogen and water. [ABSTRACT FROM AUTHOR]

Transition metal sulfide catalysts with abundant reserves and low prices exhibit high activity for hydrogen production from photocatalytic water splitting and are ideal choices to replace precious metal platinum catalysts. The preparation methods, structural morphologies and hydrogen production rates of transition metal sulfide catalysts for hydrogen production from photocatalytic water splitting were reviewed. Strategies for improving the efficiency of hydrogen production from photocatalytic water splitting by transition metal sulfide catalysts and their composite catalysts were discussed, including expanding the light absorption range, enhancing the separation of photogenerated electron-hole pairs and promoting catalyst surface reactions, to prepare more efficient transition metal sulfide catalysts that meet commercial requirements. At last, the future research trends in the field of hydrogen production from photocatalytic water splitting by transition metal sulfide catalysts were prospected. [ABSTRACT FROM AUTHOR]

VS4 has a unique layered atomic chain structure and has the potential to become a high-performance cathode material of magnesium-ion batteries with a high capacity and long cycle life. However, low conductivity and sluggish Mg2+ diffusivity during cycling limit its practical application in large-scale energy storage. Herein, a cooperative assembly-directed strategy is adopted to synthesize VS4 nanorods grown in situ on carbon nanotubes (CNTs/VS4). VS4 nanorods are tightly anchored to CNTs through V–O–C interface covalent bonds, and CNTs can enhance the electronic conductivity of the nanocomposite. In addition, the ion insertion reaction using Mg2+ and MgCl+ as carriers reduces the polar barrier for divalent Mg2+ ion transport. This rationally designed architecture promotes ion diffusion and electron transfer, thus facilitating reaction kinetics. The cooperative assembly-oriented strategy can endow CNTs/VS4 with excellent magnesium storage properties, including a high reversible capacity of 223.2 mAh g−1 at a current density of 50 mA g−1, a remarkable discharge capacity of 91.8 mAh g−1 even at 2,000 mA g−1, and an impressive capacity retention of 85.2% after 1,000 cycles at 500 mA g−1. Moreover, this strategy can serve as a general synthetic method for the complexation of VS4 with other carbon nanostructures. [ABSTRACT FROM AUTHOR]

Abstract Electrochemical CO2 reduction (ECR) to value-added products is regarded as a sustainable strategy to mitigate global warming and energy crisis, and designing highly efficient and robust catalysts is essential. In this work, transition metal sulfides (TMS)-decorated CuS microflower-like structures were prepared via the one-pot hydrothermal synthesis method for ECR to CO, and the influence of TMS doping on ECR performance was demonstrated. Characterization of the catalysts was performed using XRD, FESEM-EDS, N2 physisorption, and XPS, revealing the successful loading of TMS, the formation of microflower-like architectures and the generation of sulfur vacancies. Electrochemical tests demonstrated that doping ZnS, Bi2S3, CdS and MoS2 improved the intrinsic CO2 reduction activity of the CuS catalyst. Particularly, the MoS2-CuS composite catalyst with imperfect petal-like structure showed uniform distribution of edge Mo sites, which worked synergistically with the formed grain boundaries (GBs) and undercoordinated S vacancy sites in promoting CO2 activation, stabilizing *COOH adsorption, facilitating *CO desorption, and lowering the energy barrier of the potential-limiting step for improved CO selectivity. The MoS2-CuS catalyst achieved a maximum CO selectivity of 83.2% at –0.6 V versus the reversible hydrogen electrode (RHE) and a high CO cathodic energetic efficiency of 100%. At this potential, the catalyst maintained stable catalytic activity and CO selectivity during a 333-min electrolysis process. The findings will offer a promising avenue for the development of efficient and stable catalysts for CO production from ECR.

Electrodeposition, a binder-free technique, enables the formation of uniform and well-defined structures on the electrode surface. Herein, the material has directly grown on nickel foam by deposition through cyclic voltammetry at a fixed scan rate. The surface morphology of as-synthesized electrodes is observed with SEM and the electrochemical examination has been performed in three-electrode assembly. The highest specific capacitance attained from GCD analysis for MnS is 1453 F/g, CoS has 2476 F/g and CuS exhibits 1908 F/g at 6 A/g current density. The quantitative investigation of the inherent charge storage mechanism of an individual electrode is achieved by implementing different mathematical models on experimental data sets. The electrodes displayed a more diffusive contribution which uncovered our findings that each electrode illustrates the battery-grade properties. The results suggested that the fabricated electrode consumes an excellent potential as a high energy source for hybrid energy storage devices. [ABSTRACT FROM AUTHOR]

Electrochemical CO2 reduction (ECR) to value-added products is regarded as a sustainable strategy to mitigate global warming and energy crisis, and designing highly efficient and robust catalysts is essential. In this work, transition metal sulfides (TMS)-decorated CuS microflower-like structures were prepared via the one-pot hydrothermal synthesis method for ECR to CO, and the influence of TMS doping on ECR performance was demonstrated. Characterization of the catalysts was performed using XRD, FESEM-EDS, N2 physisorption, and XPS, revealing the successful loading of TMS, the formation of microflower-like architectures and the generation of sulfur vacancies. Electrochemical tests demonstrated that doping ZnS, Bi2S3, CdS and MoS2 improved the intrinsic CO2 reduction activity of the CuS catalyst. Particularly, the MoS2-CuS composite catalyst with imperfect petal-like structure showed uniform distribution of edge Mo sites, which worked synergistically with the formed grain boundaries (GBs) and undercoordinated S vacancy sites in promoting CO2 activation, stabilizing *COOH adsorption, facilitating *CO desorption, and lowering the energy barrier of the potential-limiting step for improved CO selectivity. The MoS2-CuS catalyst achieved a maximum CO selectivity of 83.2% at –0.6 V versus the reversible hydrogen electrode (RHE) and a high CO cathodic energetic efficiency of 100%. At this potential, the catalyst maintained stable catalytic activity and CO selectivity during a 333-min electrolysis process. The findings will offer a promising avenue for the development of efficient and stable catalysts for CO production from ECR. [ABSTRACT FROM AUTHOR]

Supercapattery is an ideal energy storage device combining the features of supercapacitors and batteries, offers a high‐energy density as well as high‐power density with extended operational lifespan. In this work, zinc sulfide (ZnS) and zinc sulfide/nickel oxide (ZnS/NiO) nanocomposite was synthesized via chemical coprecipitation method and characterized using state‐of‐the‐art analytical tools. The ZnS/NiO electrode exhibited remarkable electrochemical performance as an electrode material than pure ZnS. The ZnS/NiO nanocomposite exhibited high crystallinity, and spherical nanoparticles with an average grain size of 20–40 nm having a homogeneous dispersion. The ZnS/NiO electrode exhibited an ultrahigh specific capacity of 1803.87 Cg−1 at a relatively low scan rate of 10 mVs−1 in a 1 M KOH solution from cyclic voltammetry and 393 Cg−1 at 16 Ag−1 from charge discharge measurements, and it showed exceptional cycling stability (98 % capacity retention after 1000 cycles). Furthermore, the ZnS/NiO symmetric supercapattery device exhibited 44.43 Fg−1 specific capacitance, 5.52 Wh kg−1 energy density, and 1600 Wkg−1 power density at current density of 0.8 Ag−1 in 1 M KOH solution from galvanostatic charge discharge. After 3000 cycles, the ZnS/NiO nanomaterial demonstrated promising cyclic stability of 95 %. The ZnS/NiO supercapattery nanocomposite might be considered as a potential hybrid electrode material for the future development of electrochemical energy storage devices. [ABSTRACT FROM AUTHOR]

Developing a reasonable design of a lithiophilic artificial solid electrolyte interphase (SEI) to induce the uniform deposition of Li+ ions and improve the Coulombic efficiency and energy density of batteries is a key task for the development of high-performance lithium metal anodes. Herein, a high-performance separator for lithium metal anodes was designed by the in situ growth of a metal–organic framework (MOF)-derived transition metal sulfide array as an artificial SEI on polypropylene separators (denoted as Co9S8-PP). The high ionic conductivity and excellent morphology provided a convenient transport path and fast charge transfer kinetics for lithium ions. The experimental data illustrate that, compared with commercial polypropylene separators, the Li//Cu half-cell with a Co9S8-PP separator can be cycled stably for 2000 h at 1 mA cm−2 and 1 mAh cm−2. Meanwhile, a Li//LiFePO4 full cell with a Co9S8-PP separator exhibits ultra-long cycle stability at 0.2 C with an initial capacity of 148 mAh g−1 and maintains 74% capacity after 1000 cycles. This work provides some new strategies for using transition metal sulfides to induce the uniform deposition of lithium ions to create high-performance lithium metal batteries. [ABSTRACT FROM AUTHOR]

It is of great significance to use biomass resources to prepare electrocatalysts for hydrogen evolution reaction (HER) during water splitting. Herein, using egg white as S source (adding Na2MoO4 only), we fabricate amorphous N/P-doped molybdenum oxygen sulfide grown on Ni foam (NF) via a facile one-pot hydrothermal method. N and P elements in egg white can be partially doped into MoOxSy to produce the electrocatalyst used for HER. Under different reaction temperature of m °C (m = 160, 170, 180) and mole number of n (n = 6, 10, 12 mmol) of the Mo salt (Na2MoO4) added, series of N/P-MoOxSy/NF-m–n materials are obtained. The loose and porous morphology of the MoOxSy/NF-m–n is conducive to full contact with the electrolyte, and N/P doping can optimize the electronic structure, together improving the HER performance. The optimized electrocatalyst of N/P-MoOxSy/NF-170–10 (m = 170, n = 10) shows the best HER activity and stability, requiring a much low overpotential of 122 mV to achieve the current density of 10 mA cm−2 (η10 = 122 mV), and operating long-term (≥ 40 h) electrolysis at a constant potential of − 130 mV (vs. RHE) in acidic media (0.5 M H2SO4). The electrocatalytic property is comparable to or even beyond the known HER electrocatalysts derived from biomass. This work provides a new strategy for the design of non-metal-doped catalysts using biomass as raw materials. [ABSTRACT FROM AUTHOR]

Amino acids are one of the most important building blocks of life. During the biochemical process of translation, cells sequentially connect amino acids via amide bonds to synthesize proteins, using the genetic information in messenger RNA (mRNA) as a template. From a prebiotic perspective (i.e., without enzymatic catalysis), joining amino acids to peptides via amide bonds is difficult due to the highly endergonic nature of the condensation reaction. We show here that amides can be formed in reactions catalyzed by the transition metal sulfides from acetylene, carbon monoxide and ammonia under aqueous conditions. Some α- and β-amino acids were also formed under the same conditions, demonstrating an alternative cyanide-free path for the formation of amino acids in prebiotic environments. Experiments performed with stable isotope labeled precursors, like 15NH4Cl and 13C-acetylene, enabled the accurate mass spectroscopic identification of the products formed from the starting materials and their composition. Reactions catalyzed using the transition metal sulfides seem to offer a promising alternative pathway for the formation of amides and amino acids in prebiotic environments, bypassing the challenges posed by the highly endergonic condensation reaction. These findings shed light on the potential mechanisms by which the building blocks of life could have originated on early Earth. [ABSTRACT FROM AUTHOR]

Supercapacitor (SC) devices holds an important position between traditional capacitors and ion batteries in terms of energy density and power density values. In particular, SC′s greater power density values than Li‐ion batteries make them useful for some specific applications, such as storing energy in hybrid cars while the car slows down. Increasing energy density values is one of the key challenges for the SC community. Transition metal dichalcogenides (TMDCs), are one of the new developing important material systems to have this potential, compared to their counterparts' transition metal oxides and conductive polymers. This review is about giving insight into the electrochemical performances of two‐dimensional (2D) layered transition metal sulfides (TMS) such as MoS2, WS2, TaS2, NbS2, VS2, TiS2 and ZrS2 materials. On the other hand, the methods mostly used in synthesizing these materials are presented. [ABSTRACT FROM AUTHOR]

Transition metal sulfides (TMSs) still confront the challenges of capacity fading and inferior fast‐charging capability for sodium storage. The rational design of heterostructures enables a new approach to conquer these drawbacks. In this work, a hierarchical structure consisting of SnS2 nanosheets and FeS2 microrods with triphasic heterostructures is proposed by the facile secondary growth and sulfidation process. The introduction of tin sources regulates the proportion of pyrite and marcasite phases, thereby achieving the triphasic heterostructures comprising pyrite, marcasite FeS2, and SnS2. When served as anode material for sodium‐ion batteries, the optimized sample exhibits a high reversible capacity (901 mAh g−1) and durable cycling performances (827 mAh g−1 after 200 cycles at 1 A g−1 and 742 mAh g−1 after 700 cycles at 5 A g−1). Paring with the commercial Na3V2(PO3)3 cathodes, the full‐cell also delivers extraordinary cyclic stability with a high capacity of 618 mAh g−1 (based on the weight of anode material) after 200 cycles at 1 A g−1 (98.7% capacity retention). The hierarchical structure with adjustably triphasic heterogeneous interfaces alleviates the volumetric expansion and interfacial passivation of active material, while modulating the energy band structure and inducing the build‐in electric fields to boost Na+/electrons transport rate. [ABSTRACT FROM AUTHOR]

The commercialization of Li−S batteries is seriously hindered by polysulfides with severe shuttle effect, and the inherent insulating properties and slow reaction kinetics of insoluble Li2S products. Transition metal sulfides (TMSs) have a high adsorption capacity for polysulfides and have been shown to have a strong catalytic effect on polysulfide conversion reactions. This paper reviews the research on the application of Unary TMSs, heterostructures, etc. in Li−S batteries, and gives some research methods for TMD catalysts in Li−S batteries. Finally, it points out the main focuses and direction of future Li−S battery research and development. It aims to provide some insights into the design and manufacture of advanced Li−S batteries for commercial use. [ABSTRACT FROM AUTHOR]

[Display omitted] • PBA@CCH nanocubes are successfully constructed via an in-situ epitaxial growth strategy. • The morphology and structure of the coating can be modulated by varying the composition of reaction reagents. • The formation mechanism of the coating with variable morphology are discussed and analyzed in detail. • The CoNi2S4/Co9S8@Co4S3 heterogeneous nanocubes are fabricated via one-step carbonization and sulfidation method. Construction of Prussian blue analogues (PBAs) with heterostructure is beneficial to preparing PBAs derivatives with superior electrochemical performance. In this work, the core–shell nanostructured nanocubes composed of nickel hexacyanocobalt PBA (NiCo-PBA)@cobalt carbonate hydroxide (CCH) are synthesized through an in-situ epitaxial growth strategy, and the formation mechanisms of coating are carefully validated and specifically discussed. Then, the precursors are successfully transformed into hierarchical CoNi 2 S 4 /Co 9 S 8 @Co 4 S 3 via the gas-phase vulcanization method. Benefiting from the intriguing heterostructure and multicomponent sulfides, the CoNi 2 S 4 /Co 9 S 8 @Co 4 S 3 -80 electrode exhibits a high specific capacity of 799 ± 16C/g (specific capacitance of 1595 ± 31F/g) at 1 A/g, ultra-high capacity retention of 80 % at a high current density of 20 A/g. The assembled asymmetric supercapacitor (ASC) device delivers a high energy density of 43.3 Wh kg−1 at a power density of 899 W kg−1 and exhibits superior cycling stability with the capacity retention of 88 % after 5,000 cycles. Subsequently, the fabricated all-solid-state ASC device shows an excellent energy density of 36.4 Wh kg−1 with a power density of 824 W kg−1. This work proposing rational design of combining multicomponent sulfides and core–shell heterostructure based on PBA nanocubes opens up a novel route for developing asymmetric supercapacitor electrode materials with superior performance. [ABSTRACT FROM AUTHOR]

In this study, we synthesized a transition metal sulfide (TMS) with a spinel structure, i.e., MnIn2S4 (MIS), using a two-step hydrothermal and sintering process. In the context of lithium-ion battery (LIB) applications, ternary TMSs are being considered as interesting options for anode materials. This consideration arises from their notable attributes, including high theoretical capacity, excellent cycle stability, and cost-effectiveness. However, dramatic volume changes result in the electrochemical performance being severely limited, so we introduced single-walled carbon nanotubes (SWCNTs) and prepared an MIS/SWCNT composite to enhance the structural stability and electronic conductivity. The synthesized MIS/SWCNT composite exhibits better cycle performance than bare MIS. Undergoing 100 cycles, MIS only yields a reversible capacity of 117 mAh/g at 0.1 A/g. However, the MIS/SWCNT composite exhibits a reversible capacity as high as 536 mAh/g after 100 cycles. Moreover, the MIS/SWCNT composite shows a better rate capability. The current density increases with cycling, and the SWCNT composite exhibits high reversible capacities of 232 and 102 mAh/g at 2 A/g and 5 A/g, respectively. Under the same conditions, pristine MIS can only deliver reversible capacities of 21 and 4 mAh/g. The results indicate that MIS/SWCNT composites are promising anode materials for LIBs. [ABSTRACT FROM AUTHOR]

This manuscript reports the facile preparation of Co-NSC@CBC84 porous carbon-based and self-supported catalysts containing Co 9 S 8 active species by pyrolysis and sulfidation of ZIF-67 in-situ grown on polydopamine-modified biomass bacterial cellulose. Owing to the strong synergy effect between Co-NSC nanoparticles and CBC substrate, Co-NSC@CBC84 is superior to other reported cobalt-based sulfide catalytic materials and has good stability in acidic electrolyte. [Display omitted] Metal-organic framework (MOF) derived transition metal-based electrocatalysts have received great attention as substitutes for noble metal-based hydrogen evolution catalysts. However, the low conductivity and easy detachments from electrodes of raw MOF have seriously hindered their applications in hydrogen evolution reaction. Herein, we report the facile preparation of Co-NSC@CBC84, a porous carbon-based and self-supported catalyst containing Co 9 S 8 active species, by pyrolysis and sulfidation of in-situ grown ZIF-67 on polydopamine-modified biomass bacterial cellulose (PDA/BC). As a binder-free and self-supported electrocatalyst, Co-NSC@CBC84 exhibits superior electrocatalytic properties to other reported cobalt-based sulfide catalytic materials and has good stability in 0.5 M H 2 SO 4 electrolyte. At the current density of 10 mA cm−2, only an overpotential of 138 mV was required, corresponding to a Tafel slope of 123 mV dec−1, owing to the strong synergy effect between Co-NSC nanoparticles and CBC substrate. This work therefore provides a feasible approach to prepare self-supported transition metal sulfides as HER catalysts, which is helpful for the development of noble metal-free catalysts and biomass carbon materials. [ABSTRACT FROM AUTHOR]

Anchoring of single-atom Pt2+ and Pt0 on the surface of Sb 2 S 3 NRs highly benefits to the formation of metal (Pt)-semiconductor (Sb 2 S 3) electric interaction, which synergistically improves the broadband light harvesting and promotes the Sb 2 S 3 -to-Pt electron transfer following inhibited photoexciton recombination kinetics and enhanced H proton adsorption capacity, resulting higher and more durable photoactivity for H 2 O-to-H 2 conversion. [Display omitted] • Single atomic Pt2+/Pt0 active sites were successfully anchored on the Sb 2 S 3 nanorods. • The metal (Pt)-semiconductor (Sb 2 S 3) electric interaction was formed. • The optimal composite catalyst possesses enhanced H proton adsorption capacity. • Higher and more durable photoactivity for H 2 O-to-H 2 conversion were achieved. • The mechanism of multisite cocatalysis for photoactivity improvement was elucidated. Single atomic metal (SAM) cocatalysis is a potential strategy to improve the performance of photocatalytic materials. However, the cocatalytic mechanism of SAM sites in different valence states is rarely reported. Herein, single atomic Pt2+/Pt0 active sites were anchored on Sb 2 S 3 nanorods to synergistically improve the photoactivity for hydrogen production under simulated sunlight. Experimental results and density functional theory calculations indicated that the coexistence of single atomic Pt2+/Pt0 sites synergistically improves the broadband light harvesting and promotes the Sb 2 S 3 -to-Pt electron transfer following inhibited photoexciton recombination kinetics and enhanced H proton adsorption capacity, resulting higher and more durable photoactivity for hydrogen production. Therefore, the optimal Sb 2 S 3 -Pt 0.9‰ composite catalyst achieved remarkably enhanced hydrogen evolution rate of 1.37 mmol∙g−1∙h−1 (about 105-fold greater of that of Sb 2 S 3 NRs) under faintly alkaline condition, and about 5.41 % of apparent quantum yield (AQY 700 nm) was achieved, which shows obvious superiority in hydrogen production by contrasting with the reported Sb 2 S 3 -based photocatalysts and conventional semiconductor photocatalytic materials modified with noble metals. This study elucidate a well-defined mechanism of multisite cocatalysis for photoactivity improvement. [ABSTRACT FROM AUTHOR]

We treated the reconstruction process of pyrite-type transition metal sulfides (TMSs) during oxygen evolution reaction (OER) process as a potential-dependent electrochemical reaction similar to OER, i.e. , sulfide oxidation reaction (SOR). Based on this analysis method, the reconstruction mechanism of various TMSs was elucidated and new descriptors for TMSs reconstruction were proposed: U SOR and ΔU, which provides a significant contribution to the understanding of the mechanism and quantifying this surface behavior. [Display omitted] Reconstruction universally occurs over non-layered transition metal sulfides (TMSs) during oxygen evolution reaction (OER), leading to the formation of active species metal (oxy)hydroxide and thus significantly influences the OER performance. However, the reconstruction process and underlying mechanism quantitatively remain largely unexplored. Herein, we proposed an electrochemical reaction mechanism, namely sulfide oxidation reaction (SOR), to elucidate the reconstruction process of pyrite-type TMSs. Based on this mechanism, we evaluated the reconstruction capability of NiS 2 doped with transition metals V, Cr, Mn, Fe, Co, Cu, Mo, Ru, Rh, and Ir within different doped systems. Two key descriptors were thus proposed to describe the reconstruction abilities of TMSs: U SOR (the theoretical electric potential of SOR) and ΔU (the difference between the theoretical electric potential of SOR and OER), representing the initiation electric potential of reconstruction and the intrinsic reconstruction abilities of TMSs, respectively. Our finding shows that a lower U SOR readily initiate reconstruction at a lower potential and a larger ΔU indicating a poorer reconstruction ability of the catalyst during OER. Furthermore, Fe-doped CoS 2 was used to validate the rationality of our proposed descriptors, being consistent with the experiment findings. Our work provides a new perspective on understanding the reconstruction mechanism and quantifying the reconstruction of TMSs. [ABSTRACT FROM AUTHOR]