Search

Advanced and sustainable energy storage technologies with tailorable electrochemically active materials platform are the present research dominancy toward an urgent global need for electrical vehicles and portable electronics. Moreover, intensive efforts are given to screen the widely available low‐cost materials with a focus to achieve superior electrochemical performance for the fabrication of energy storage devices. Transition metal‐based sulfides have prodigious technological credibility due to their compositional‐ and morphological‐based tunable electrochemical properties. Here the significant advances and present state‐of‐the‐art of such assured materials in different energy storage devices are discussed. Assessment of the intensive work invested in the progress of transition metals such as V, Mn, Fe, Co, Ni, Cu, Zn Mo, and W based sulfides along with their structural/compositional engineering and addressable aspects for electrochemical performance enhancement are highlighted. Additionally, discussions on critical strategies for decisive mechanistic and kinetic views for charge storage phenomena with key challenges, such as volume expansions, low stability, and sluggish kinetics, are discussed. Finally, the challenges and future prospects demands for strategic approaches of such materials with prominence in futuristic directions are concluded. This article is categorized under:Energy Efficiency > Science and MaterialsEnergy Research & Innovation > Science and Materials [ABSTRACT FROM AUTHOR]

[Display omitted] • Titration with N-bases enables quantification of active sites on sulfide catalysts. • Enhanced hydrogenation activity on Ni-promoted sulfides is unambiguously explained. • New insights are obtained into site heterogeneity and effects of H 2 and sulfur. • TOFs for polyaromatics hydrogenation differ between titrated CUS and SH. • Some sites with a minor contribution to catalysis remain unoccupied by the titrant. Quantification of active sites is indispensable for understanding a catalytic material, ultimately enabling meaningful comparisons across different catalysts and discerning the underlying intrinsic kinetics. At present, however, few methods are available for quantitatively probing the catalytic surface of transition metal sulfides (TMS) during catalysis. TMS catalysts expose Brønsted acidic (sulfhydryls, SH) and Lewis acidic sites (coordinatively unsaturated sites, CUS) at their surfaces and, thus, are conceptually amenable to in situ acid-base titration with judicious choices of bases that strongly bind to the acidic entities. In this proof-of-concept study, in situ titration using several N-containing organic bases allowed us to determine the surface concentration of active sites and their specific activities for polyaromatics hydrogenation on unsupported TMS catalysts. Ni-promoted sulfide catalysts were more active than the unpromoted ones, because of a modest increase in the site density and a 2- to 3-fold enhancement in the TOF averaged over all titrated sites. By further discriminating between the titrated CUS and SH with site-selective titrants, a substantial difference in the TOF was found between CUS and SH among the titrated pool of sites. In addition to the titrated sites that contributed to the majority (80–95%) of the hydrogenation activity, some active sites remained unoccupied by the studied base molecules. The contribution of these residual sites, likely inaccessible to large-sized and less mobile titrants, depended on the temperature, H 2 pressure and the catalyst, but was unaffected by the space time, titrant concentration, and the type or concentration of the polyaromatic reactant, for a given catalyst. This work leads to several emerging opportunities to better understand complex TMS catalysts. [ABSTRACT FROM AUTHOR]

Effective and inexpensive electrocatalysts are significant to improve the performance of oxygen evolution reaction. Facing the bottleneck of slow kinetics of oxygen evolution reaction, it is highly desirable to design the electrocatalyst with high activity, good conductivity, and satisfactory stability. In this work, nickel foam supported hierarchical Co9S8–Ni3S2 composite hollow microspheres were derived from in situ-generative MOF precursors and the subsequent sulfurization process by a simple two-step solvothermal method. The composite microspheres were directly grown on nickel foam without any binder, and nickel foam was used as the nickel source and support material. The morphology and constitution of the series self-supported electrodes were characterized by SEM, TEM, XRD, XPS, and Raman, respectively. The unique porous architecture enriched the electrode with sufficient active surface and helped to reactants and bubble evolved during electrochemical water oxidation. Through tuning the concentration of cobalt source and ligand, the content ratio of Co9S8 and Ni3S2 can be modulated. The heterostructures not only afford active interfaces between the phases but also allow electronic transfer between Co9S8 and Ni3S2. The optimized Co9S8-Ni3S2/NF-0.6 electrode with the highest electrochemical surface area and conductivity shows the best OER performance among the series electrodes in 1 M KOH solution. The overpotential of Co9S8-Ni3S2/NF-0.6 is only 233 mV when the current density is 10 mA cm−2, and corresponding Tafel slope is 116.75 mV dec−1. In addition, the current density of Co9S8-Ni3S2/NF-0.6 electrocatalyst hardly decreased during the 12 h stability measurement. Our approach in this work may provide the future rational design and synthesis of satisfactory OER electrocatalysts.

In this study, we proposed a novel CoIn2S4/reduced graphene oxide (CoIn2S4/rGO) composite anode using a hydrothermal method. By introducing electronic-conductive reduced graphene oxide (rGO) to buffer the extreme volume expansion of CoIn2S4, we prevented its polysulfide dissolution during the lithiation/de-lithiation processes. After 100 cycles, the pristine CoIn2S4 electrode demonstrated poor cycle performance of only 120 mAh/g at a current density of 0.1 A/g. However, the composition-optimized CoIn2S4/rGO composite anode demonstrated a reversible capacity of 580 mAh/g for 100 cycles, which was an improvement of 4.83 times. In addition, the ex situ XRD measurements of the CoIn2S4/rGO electrode were conducted to determine the reaction mechanism and electrochemical behavior. These results suggest that the as-synthesized CoIn2S4/rGO composite anode is a promising anode material for lithium ion batteries.

Rational designing of electrode materials is of great interest for improving the performance of battery-type supercapacitors. The bimetallic NiCo2S4 (NCS) and CoNi2S4 (CNS) electrode materials have received much attention for supercapacitors due to their rich electrochemical characteristics. However, the comparative electrochemical performances of NCS and CNS electrodes were never studied for supercapacitor application. In this work, microsphere-like bimetallic NCS and CNS structures were synthesized via a facile one-step hydrothermal method by controlling the molar ratio of Ni and Co precursors. The physico-chemical results confirmed that microsphere-like structures with cubic spinel-type NCS and CNS materials were successfully fabricated by this method. When tested as the supercapacitor electrode materials, both NCS and CNS electrodes exhibited battery-type behavior in a three-electrode configuration with outstanding electrochemical performances such as specific capacity, rate performance and cycle stability. Impressively, the CNS electrode delivered a high specific capacity of 430.1 C g−1 at 1 A g−1, which is higher than 345.9 C g−1 of the NCS electrode. Furthermore, the NCS and CNS electrodes showed a decent cycling stability with 75.70 and 84.70% capacity retention after 10,000 cycles. Benefiting from the electrochemical advantage of CNS microspheres, we fabricated a hybrid supercapacitor (HSC) device based on CNS microspheres (positive electrode) and activated carbon (AC, negative electrode), which is named as CNS//AC. The assembled CNS//AC HSC device showed a large energy density of 41.98 Wh kg−1 at a power density of 800.04 W kg−1 and displayed a remarkable cycling stability with a capacity retention of 91.79% after 15,000 cycles. These excellent electrochemical performances demonstrate that both bimetallic NCS and CNS microspheres may provide potential electrode materials for high performance battery-type supercapacitors.

The shock response of chromium sulfide-chromium, a cermet of potential interest as a matrix material for ballistic applications, has been investigated at two molar ratios. Using a combustion synthesis technique allowed for control of the molar ratio of the material, which was investigated under near-stoichiometric (cermet) and excess chromium (interpenetrating composite) conditions, representing chromium:sulfur molar ratios of 1.15:1 and 4:1, respectively. The compacts were investigated via the plate-impact technique, which allowed the material to be loaded under a onedimensional state of strain. Embedded manganin stress gauges were employed to monitor the temporal evolution of longitudinal and lateral components of stress in both materials. Comparison of these two components has allowed assessment of the variation of material shear strength both with impact pressure/strain-rate and time for the two molar ratio conditions. The two materials exhibited identical material strength despite variations in their excess chromium contents. [ABSTRACT FROM AUTHOR]

Developing lower-cost and higher-efficient photocatalysts is still a major challenge for the solar to hydrogen energy conversion by photocatalytic water splitting. Herein, P-doped Co 9 S 8 (P–Co 9 S 8) was synthesized by a hydrothermal process using low-cost RP as raw material, and then P–Co 9 S 8 was employed to construct heterojunction with g-C 3 N 4 via a mechanical-mixing method. Investigation shows that P–Co 9 S 8 can not only improve the electrical conductivity and surface area of the composite, but also can lower the over-potential of H 2 evolution, leading to an enhanced H 2 evolution kinetics. The H 2 evolution rate of resultant 25% P–Co 9 S 8 /g-C 3 N 4 reached 4362 μmol g−1 h−1 under UV and visible light, being nearly 121.2 times higher than that of g-C 3 N 4. The charge transfer between P–Co 9 S 8 and g-C 3 N 4 follows the Type-I route based on the photoelectrochemical analysis, leading to more electrons on the conduction band of P–Co 9 S 8 to participate the H 2 evolution processes. This work provides a new way for preparation of P-doped sulfides with potential applications in the field of photocatalysis. • P-doped Co 9 S 8 nanospheres was successfully fabricated via a facile hydrothermal method. • P-doped Co 9 S 8 was first employed in photocatalytic hydrogen evolution from water splitting. • H 2 evolution rate of 25% P–Co 9 S 8 /g-C 3 N 4 composite is 121.2 times higher than that of g-C 3 N 4. • The charge transfer between P–Co 9 S 8 and g-C 3 N 4 follows the Type-I route during the reaction. [ABSTRACT FROM AUTHOR]

[Display omitted] • Screening of Transition metal sulfides on HY catalysts for SRO of decalin was performed. • Comprehensive GCxGC gives a unique molecular insight of SRO reaction. • A new reaction scheme has been proposed. • New ternary systems efficient at medium temperature are proposed. Bifunctional catalysis combining acidic catalysts and sulfide active phases is usually related to hydrocracking catalysts which balances the hydrogenation function of a NiMo (NiW) alumina supported sulfide catalysts and the acidic function of a zeolite. The discovery of sulfur-resistant catalysts for selective ring opening (SRO) is an important challenge for refiners, considering the future legislation on cetane index of diesel fuels. In the present work, we studied the properties of various transition metal sulfides (TMS) supported on Y zeolite in gas-phase decalin hydroconversion at high hydrogen pressure (5 MPa) in the presence of 0.8 % H 2 S concentration. This screening shows high activities for noble metal based sulfides with a mechanism which proceeds by skeletal isomerization induced by the zeolite. Catalytic activity was improved by the use of ternary sulfides such as Ni 1-x Ru x S 2 or NiRh 2 S 4 on Y zeolites. High decalin conversion levels can be reached below 250 °C with more of 20 % of ring opening products and thanks to the use of comprehensive GC, a detailed mechanism of the SRO of decalin is given. [ABSTRACT FROM AUTHOR]

Nowadays, rational yet high value-added utilization of low-cost petroleum asphalt still faces a significant challenge. In light of its high carbon content and abundant sulfur atoms, here, an in-situ bonding sulfur strategy is proposed to fabricate transition metal (Mn, Mo, Fe, or Co)-based/carbon composites (TM-based/C). This strategy successfully achieves the conversion from thiophenic-S of asphalt into transition metal sulfides (TMSs). When tested as anodes for lithium-ion batteries (LIBs), the TM-based/C electrodes deliver better specific capacity and cycling performance than those of sulfur-doped carbon nanosheets (SCN) electrode. As a typical example, a 3D network-nanosheets structure of Mn-based/C composite is constructed, and the optimized MnO 2 /MnS 2 /C-2 electrode achieves low charging/discharging voltage platform of 1.2 V/0.58 V, and delivers long-term life of 827 mAh g−1 after 400th cycle at 0.5 A g−1. These excellent electrochemical properties benefit from its structural integrity upon cycling and the formation of MnS 2 /MnO 2 phases. Furthermore, LiFePO 4 /(MnO 2 /MnS 2 /C-2) full cell exhibits a remarkably reversible capacity of 168 mAh g−1 at 0.8C, and impressive cycling stability of 78% after 400 cycles at 1 C, better than those of LiFePO 4 /(commercial graphite). This work may provide a new perspective for the high value-added utilization of low-cost petroleum asphalt for efficient anodes toward LIBs. An in-situ bonding sulfur strategy converts thiophenic-S of asphalt to transition metal sulfides, forming transition metal-based/carbon (TM-based/C) composites. TM-based/C electrodes deliver better specific capacity and cycling ability, and the LiFePO 4 /(MnO 2 /MnS 2 /C-2) full cell exhibits a remarkably reversible capacity. [Display omitted] • High value-added utilization of low-cost petroleum asphalt is achieved. • The thiophenic-S of asphalt is converted into transition metal sulfides. • A 3D network-nanosheets structure of MnO 2 /MnS 2 /C-2 composite is constructed. • Transition metal-based/carbon electrodes deliver excellent rate and cycling performance. • LiFePO 4 /(MnO 2 /MnS 2 /C-2) full cell exhibits impressive cycling stability of 78% after 400 cycles. [ABSTRACT FROM AUTHOR]

Transition metal sulfide nanoparticles are a source of attraction for different applications, especially in optoelectronics and catalysis, however, their uses in biomedicine are not well explored. To fill this vacuum, we have reported the different physical properties and biological applications of ZnS, MnS and NiS nanoparticles synthesized by a single precursor-based route. Techniques like p-XRD, UV–Vis, TEM and TGA were used to establish their physical properties, whereas, there in vitro antibacterial, antifungal, antioxidant, cytotoxic and hemolytic potential were studied. XRD pattern revealed a single pure phase and sharp peaks owing to the crystalline nature of the nanoparticles. TEM images indicated a different morphology (spherical to cube like) while the size of the nanoparticles was in the order of ZnS (6.5 nm) < MnS (13–24 nm) < NiS (50–90 nm). Antimicrobial potential was established using well-diffusion assay across different concentrations (250 µg/mL to 4 mg/mL). It was observed that the MnS nanoparticles inhibited all of the bacterial strains in the up to 500 µg/mL, however, at 250 µg/mL, 7 and 6.5 mm inhibition zones were revealed for B. subtilis and E. coli, respectively, while the other strains revealed no susceptibility. NiS nanoparticles inhibited S. epidermidis across all the tested concentrations and revealed inhibitory zones from 10 to 6.5 mm across 4 mg/mL to 250 µg/mL. As compared to the antibacterial properties, it was observed that the metal sulfides revealed excellent antifungal potential. All of the tested fungal strains revealed zones of inhibition across the tested concentrations of MnS, NiS and ZnS. Furthermore, the highest concentration i.e. 4 mg/mL revealed high potency then positive control in some cases for example the NiS revealed zone of 20 mm as compared to the 13 mm of antibiotic for A. niger. DPPH free radical scavenging potential was found as MnS-NPs > NiS-NPs > ZnS-NPs. Brine shrimp lethality and hemolysis assays revealed cytotoxic and hemolytic nature which decreased in a dose dependent manner. Our insights into the application of metal sulfide nanoparticles reveals promises, however, we strongly encourage studies on the mechanistic aspects as well as their toxicity in vivo. [ABSTRACT FROM AUTHOR]

Globally, millions of people die of microbial infection-related diseases every year. The more terrible situation is that due to the overuse of antibiotics, especially in developing countries, people are struggling to fight with the bacteria variation. The emergence of super-bacteria will be an intractable environmental and health hazard in the future unless novel bactericidal weapons are mounted. Consequently, it is critical to develop viable antibacterial approaches to sustain the prosperous development of human society. Recent researches indicate that transition metal sulfides (TMSs) represent prominent bactericidal application potential owing to the meritorious antibacterial performance, acceptable biocompatibility, high solar energy utilization efficiency, and excellent photo-to-thermal conversion characteristics, and thus, a comprehensive review on the recent advances in this area would be beneficial for the future development. In this review article, we start with the antibacterial mechanisms of TMSs to provide a preliminary understanding. Thereafter, the state-of-the-art research progresses on the strategies for TMSs materials engineering so as to promote their antibacterial properties are systematically surveyed and summarized, followed by a summary of the practical application scenarios of TMSs-based antibacterial platforms. Finally, based on the thorough survey and analysis, we emphasize the challenges and future development trends in this area. [ABSTRACT FROM AUTHOR]

In this work, we demonstrate the fabrication of vertically aligned carbon nanowalls (CNW) enrobed with porous molybdenum sulfide (MoSx) as electrode for electrochemical capacitors with large areal capacitance that can be used for micro-supercapacitors. The deposition of MoSx onto the CNW electrode was performed using hydrothermal technique allowing a good coverage of the deposit along the CNW. The electrode can deliver an areal capacitance as high as 366 mF cm−2 (which is one of the highest reposted in the case of MoSx). Our strategy allows using hydrothermal technique to deposit different transition metal sulfides onto porous template in order to obtain materials with high specific capacitance and highlight CNW as promising template to deposit different materials for high-performance energy storage systems. [ABSTRACT FROM AUTHOR]

Non-noble electrocatalysts (such as transition metal sulfides) have been attractive to substitute noble-metal catalysts for oxygen evolution reaction (OER) to advance the practical application of clean energy. Herein, a Fe-doped CoS2 nanoparticles supported CoS2 microspheres@N-doped carbon (Fe-CoS2/CoS2@NC) is prepared as an efficient OER electrocatalyst. The Fe-CoS2/CoS2@NC composite is derived by sulfurizing the metanilic-intercalated Co(OH)2 microspheres decorated with binary active CoFe-Prussian blue analogue (CoFe-PBA) nanoparticles. The obtained composite combines the advantageous characteristics for enhancing electrocatalytic performances: binary active Fe-CoS2 derived from CoFe-PBA, active CoS2, N-doped carbon scaffold to improve electronic conductivity, the appropriate specific surface area and meso/macroporous size distribution to afford rich active sites. The Fe-CoS2/CoS2@NC requires an overpotential of 300 mV to reach a current density of 10 mA cm−2 with a Tafel slope of 72 mV dec−1 in 1.0 M KOH, outperforming those of NC/CoS2, NC/Fe-CoS2 and CoS2. Furthermore, the enhancement is experimentally supported by the low charge-transfer resistance and the large electrochemical active surface area during the OER. The synthesis approach could be extended to provide a tunable hydroxide/PBAs precursor-based approach for designing and preparing hierarchical structures as electrocatalysts. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Central South University is the property of Springer Nature 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 development of nanomaterials that mimic oxidase-like activities has recently attracted an increasing amount of attention. Obtaining highly active and cost-effective oxidase mimics has posed a significant challenge in this area of research. In this study, we successfully synthesized nickel-doped ferrous disulfide nanocubes (Ni–FeS 2) via a facile one-step method. Characterization by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed that Ni was predominantly distributed within the surface layer of the Ni–FeS 2 nanocubes. The incorporation of nickel in density functional theory (DFT) calculations effectively reduced the d-band center of Fe, resulting in weakened adsorption to intermediates and thereby enhancing its catalytic efficiency. Moreover, we developed a novel approach based on Ni–FeS 2 (the Ni–FeS 2 method) for detecting reducing substances, which exhibited good sensitivity toward ascorbic acid (AA), glutathione (GSH), and cysteine (Cys). Remarkably, the established Ni–FeS 2 method was successfully employed for in vitro assessment of total antioxidant capacity (TAC) in cellular and organ samples, thereby enabling discrimination between normal, senescent, and malignant cells as well as distinguishing among healthy liver tissue, cancerous liver tissue, and metastatic organs. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Electronic structure modulation of the Ni active site in the NiFeS via metal doping. • Cr significantly induces the formation of oxyhydroxide, followed by Ti, V, and Ag. • Ti accelerates the reaction kinetics, followed by Ag, Cr, and Zn. • Ti effectively modulates the CO 2 adsorption energy, giving facile CO 2 desorption. • NiFeTiS exhibits an excellent UOR potential of 1.36 V at 100 mA cm−2. Enhancement of urea oxidation reaction (UOR) activity of NiFe sulfide via metal doping, including V, Zn, Cr, Ag, and Ti, is demonstrated. X-ray photoelectron and absorption spectroscopy analyses show different degrees of electronic structure modulation of the Ni site due to the doping of the third metals having different t 2g and e g occupancies. Cr reduces the energy needed for the in-situ formation of the oxyhydroxide, followed by Ti, V, and Ag. The reaction kinetics is accelerated by Ti, followed by Ag, Cr, and Zn. Ti also optimizes the d-band center and CO 2 adsorption energy, which is supported by density functional theory calculation. Self-reconstructed sulfate-containing oxyhydroxide during UOR is demonstrated via in-situ Raman and post-transmission electron microscopy analyses. The sulfate is also found to affect the potential required for the formation of the oxyhydroxide. The optimized NiFeTi-containing sulfide exhibits an excellent UOR potential of 1.36 V at 100 mA cm−2 and is stable up to 80-h. This work provides a strategy and deep understanding in enhancing UOR performance of sulfide catalyst. [ABSTRACT FROM AUTHOR]

[Display omitted] • A series of NiMnS/carbon fibers (CFs) was made as anodes by regulating Ni/Mn ratio. • NiMnS/CFs delivered the final discharge capacities of 730 mA h g−1 at 0.1 A g−1. • After 250 cycle, NiMnS/CFs exhibited 99% of capacity retention at 1 A g−1. • DFT predicts fast charge–discharge rate with low diffusion energy barrier for Li+. • NiMnS/CFs-based full cell shows a specific energy 529 W h kg−1 and stable durability. Transition metal sulfides (TMSs) have been appraised as promising anode materials for lithium-ion batteries (LIBs), however, the average conductivity and drastic pulverization produced by specific volume variation during discharge–charge cycles limit their practical application. To resolve these critical issues, an in-situ fabrication approach has been utilized to develop binary TMS-embedded carbon nanofibers (CFs) by regulating the loading of metallic (cationic) components. Herein, a series of NiMnS/CFs-n composites was prepared by controlling Ni/Mn feeding ratios (n) via successive electrospinning, carbonization and sulfidation method. The inventive engineering procedure provides excellent durability (∼99 % compared to 2nd cycle) up to 250 cycles at 1 A g−1 and superb rate performance for NiMnS/CFs-2.0 anode. The final discharge capacities of NiMnS/CFs-2.0 are 730, 608, 562, 468, 370, and 306 mA h g−1 at 0.1, 0.3, 0.5, 1, 3, and 5 A g−1, respectively. Theoretical calculations enable us to understand the role of typical Ni/Mn feeding ratio on electronic properties and confirm that the hybrid NiMnS/CFs-2.0 surface provides enhanced material conductivity, improved Li adsorption energies for S-top sites, and fast discharge–charge rate with low diffusion energy barrier. Meanwhile, the full-cell containing NiMnS/CFs-2.0 anode outperforms the commercialized graphite anode with a high specific energy of ∼529 W h kg−1 and stable durability, which also successfully enlightens a light bulb. The present study will provide a scalable and simple method to fabricate the integrated composite of binary TMS/CFs by proper cationic regulation and offer useful guidelines for commercial applications of TMS-based anode. [ABSTRACT FROM AUTHOR]

Supercages of faujasite (FAU)‐type zeolites serve as a robust scaffold for stabilizing dinuclear (Mo2S4) and tetranuclear (Mo4S4) molybdenum sulfide clusters. The FAU‐encaged Mo4S4 clusters have a distorted cubane structure similar to the FeMo‐cofactor in nitrogenase. Both clusters possess unpaired electrons on Mo atoms. Additionally, they show identical catalytic activity per sulfide cluster. Their catalytic activity is stable (>150 h) for ethene hydrogenation, while layered MoS2 structures deactivate significantly under the same reaction conditions. [ABSTRACT FROM AUTHOR]

The successful development of post‐lithium technologies depends on two key elements: performance and economy. Because sodium‐ion batteries (SIBs) can potentially satisfy both requirements, they are widely considered the most promising replacement for lithium‐ion batteries (LIBs) due to the similarity between the electrochemical processes and the abundance of sodium‐based resources. Among various SIB anode materials, metal sulfides are most extensively studied as materials for high‐performance electrodes due to the versatility of their synthesis procedure, utilization potential, and high sodiation capacity. Herein, some of the most effective strategies aimed at effectively alleviating the performance shortcomings of these materials from the materials engineering/design perspective are summarized. In terms of facilitating ion transport in SIBs, which represents one of the most critical aspects of their performance, a specific family of strategies related to a particular operational mechanism is considered rather than categorizing based‐on individual sulfide materials. In the foreseeable future, the development of highly functional SIBs electrode materials and utilization of metal sulfides will become highly relevant due to their stability and performance characteristics. Therefore, it is anticipated that this review will guide further research and facilitate the realization of various applications of sulfide‐based high‐performance rechargeable batteries. [ABSTRACT FROM AUTHOR]

Designing and constructing transition metal sulfides (TMSs) as oxygen evolution reaction (OER) electrocatalysts has been attracting increasing attention. Interface engineering can effectively modify the active sites and promote electron transfer, resulting in improvement of electrocatalytic performance. Here, freestanding heterogeneous CoS2/CoS nanosheets are prepared via a simple one‐step sintering process from a kind of novel hierarchical tremella‐like metal–organic framework (MOF). The formation mechanism of the unique MOF and the heterojunctions between CoS2 and CoS is analyzed. Consequently, the prepared cost‐effective OER electrocatalyst achieves satisfying electrocatalytic efficiencies with a diminutive overpotential of 269 mV at 10 mA cm−2 current density, a small Tafel slope of 52 mV dec−1, and good stability in alkaline solution comparable to RuO2 counterparts. This work opens up a new method for constructing 2D electrocatalysts containing catalytic interfaces with boosted OER performance. [ABSTRACT FROM AUTHOR]

The traditional recycling methods of the spent lithium ion batteries (LIBs) involve the intricate and cumbersome steps. This work proposes a facile method of acid leaching followed by the sulfurization treatment to achieve the high Li leaching efficiency, and obtain high-performance multi-function electrocatalysts for oxygen reduction (ORR), oxygen evolution (OER), and methanol oxidation reactions (MOR) from the spent LIB ternary cathodes. By this method, the Li leaching efficiency from the spent LIB ternary cathode can reach 98.3%, and the transition metal sulfide heterostructures (LNMCO-H-450S) consisting MnS, NiS 2 , and NiCo 2 S 4 phases can be obtained. LNMCO-H-450S shows the superior bifunctional oxygen catalytic activities with ORR half-wave potential of 0.763 V and OER potential at 10 mA cm -2 of 1.561 V, surpassing most of the state-of-the-art electrocatalysts. LNMCO-H-450S also demonstrates the superior MOR catalytic activity with the potential at 100 mA cm -2 being 1.37 V. Using LNMCO-H-450S as the oxygen catalyst, this work can construct the aqueous and solid-state zinc-air batteries with high power density of 309 and 257 mW cm -2 , respectively. This work provides a promising strategy for the efficient recovery of Li, and reutilization of Ni, Co, and Mn from the spent LIB ternary cathodes., (© 2023 Wiley‐VCH GmbH.)

Heterogeneous catalysis is essential to most industrial chemical processes. To achieve a better sustainability of these processes we need highly efficient and highly selective catalysts that are based on earth-abundant materials rather than the more conventional noble metals. Here, we discuss the potential of inorganic materials as catalysts for chemical transformations focusing in particular on the promising transition metal phosphides and sulfides. We describe our recent and current efforts to understand the interfacial chemistry of these materials that governs catalysis, and to tune catalytic reactivity by controlled chemical modification of the material surfaces and by use of interfacial electric fields., (Copyright 2024 Tzu-Chin Chang Chien, Murielle F. Delley. License: This work is licensed under a Creative Commons Attribution 4.0 International License.)

Ni-Mo/γ-Al2O3 catalysts with different Ni loadings were prepared. They were characterized by X-ray diffraction (XRD), N2 adsorption, IR spectra of adsorbed pyridine (Py-IR), temperature-programmed desorption of ammonia (NH3-TPD), temperature-programmed reduction of H2 (H2-TPR), and high resolution transmission electron microscopy (HRTEM). The hydrodenitrogenation (HDN) performance of catalysts for coal tar were evaluated. The best hydrodenitrogenation activity was observed on the catalysts with a Ni loading of 6.25 wt% and a Ni/(Ni+Mo) ratio of 0.4. Also, the methods of co-impregnation and sequence-impregnation were compared. The denitrification rate of co-impregnation catalyst NiMo-5-co (71.2%) was slightly lower than that of sequence-impregnation catalyst NiMo-5 (71.7%). Disparate product distribution was obtained on NiMo-5-co and NiMo-5. The dispersion of active components, the distribution of pore and acid on catalysts played an important role in HDN process of coal tar. [ABSTRACT FROM AUTHOR]

The transition metal sulfides have gained extensive interest in energy storage devices owing to their unique features. However, the research-based on cobalt, copper and manganese sulfide composites is limited while they are considered as promising contenders for supercapacitor electrodes. The simplest and facile one-step electrodeposition technique was adopted for the direct growth of CuMnS and CoMnS on a Ni-substrate. The electrochemical properties of CuMnS and CoMnS electrodes were investigated and maximum specific capacitances of 1691 and 2290 F/g, respectively, were obtained at 10 A/g current density. Further, these electrodes are investigated with activated carbon (AC) electrode to fabricate asymmetric supercapacitor devices where CoMnS//AC exhibited superior energy density values than CuMnS//AC device. However, both the devices show a relatively uniform capacitance retention rate (~94%) after 2500 charging-discharging cycles. Furthermore, the role of capacitive- and diffusive-controlled contributions in the charge storage phenomenon of supercapacitor devices are explicitly scrutinized by employing Dunn's model. Co-electrodeposition of transition metal sulfides has great potential as electrode material for highly effective supercapacitor devices. [ABSTRACT FROM AUTHOR]

Transition‐metal sulfides (TMSs) are extensively investigated as anodes of low‐cost sodium‐ion batteries (SIBs) and potassium‐ion batteries (KIBs) due to their abundant resources and high theoretical capacity. However, their poor cyclability and low initial coulombic efficiency (ICE) in ester‐based electrolytes severely impede their application in SIBs and KIBs. To overcome these drawbacks, ether‐based electrolytes are considered as alternatives, but its fundamental principle remains rarely reported and poorly understood. Herein, the electrochemical performance of MoS2@C electrodes is explored using both carbonate and ether‐based solvents. The MoS2@C exhibits a higher ICE and Na/K‐ion storage capacity (a reversible specific capacity of 625 mAh g−1 with ICE of 80% for SIBs, and a capacity of 241 mAh g−1 with ICE of 81% for KIBs, respectively) in dimethyl ether (DME) electrolytes than in ethylene carbonate and diethylene carbonate (EC/DEC) electrolytes. Experimental measurements and theoretical calculation show that the DME electrolytes help to optimize the solid‐electrolyte interphase (SEI) composition, facilitate charge transport, reduce the energy barrier for Na/K‐ions migration and reinforcing geometry architecture, thus endowing excellent electrochemical performance. Importantly, this electrolyte optimization solution can be extended to other TMSs, such as Fe7S8@C anodes, demonstrating an exact match between the TMSs and DME electrolytes. [ABSTRACT FROM AUTHOR]

A cost-effective counter-electrode based on the NiCo 2 S 4 /carbon nanofibers (NiCo 2 S 4 @C/CNFs) has been synthesized by a combined two-step process of electrospinning and hydrothermal method. With NiCo 2 S 4 @C/CNFs nanocomposite as counter electrode, the dye-sensitized solar cells can deliver an overall power conversion efficiency of 9.00% at 100 mW cm−2 illumination (AM 1.5G), which is significantly higher than 7.48% of the expensive Pt counterpart. • Electrospun and hydrothermal techniques were used to synthesize NiCo 2 S 4 /CNFs. • The NiCo 2 S 4 /CNFs composite was used as counter electrode in DSSCs for the first time. • The DSSCs based on NiCo 2 S 4 /CNFs that achieved a PCE of 9.00%. Possing excellent catalytic performance about counter electrode (CE) is the prerequisite for obtaining high performance dye sensitized solar cells (DSSCs). Herein, The NiCo 2 S 4 /carbon nanofibers (NiCo 2 S 4 /CNFs) are successfully synthetised via hydrothermal and electrospinning method, and then directly used in DSSCs. Owing to the synergistic effect between the catalytic of NiCo 2 S 4 materials and the electrical conductivity of CNFs, All chemical measurements reveal that NiCo 2 S 4 /CNFs applied in DSSCs exhibit good power conversion efficiency (9.0%) and stability, which surpass that of DSSCs with Pt CE (7.48%), indicating that NiCo 2 S 4 /CNFs composite would be helpful for the low-cost and efficient application of DSSCs. [ABSTRACT FROM AUTHOR]

High-activity and cost-effective transition metal sulfides (TMSs) have attracted tremendous attention as promising catalysts for hydrogen evolution reaction (HER). However, a significant challenge is the simultaneous construction of abundant electrochemical active sites and the fast electronic transmission path to boost a high-efficient HER. Herein, we demonstrate a facile one-step hydrothermal preparation of MoS 2 hollow nanospheres decorating Ni 3 S 2 nanowires supported on Ni foam (NF), without any other additional template, surfactant or annealing. In this three-dimensional (3D) heterostructure, the ultrathin-layered MoS 2 hollow nanospheres contribute to the promotion of the total surface area and the electrochemical active sites. Meanwhile, the Ni 3 S 2 nanowires are beneficial to the high electrical conductivity. Consequently, the optimized MoS 2 /Ni 3 S 2 /NF-200-24 electrocatalyst presents an extremely superior HER activity to that of individual MoS 2 /NF and Ni 3 S 2 /NF. The HER overpotentials are 85 mV at 10 mA cm−2 and 189 mV at 100 mA cm−2, which are also comparable with the state-of-the-art 20% Pt/C/NF electrode at both low and high current. Ultrathin-layered MoS 2 hollow nanospheres decorating Ni 3 S 2 nanowires self-supporting electrode were synthesized via the one-step hydrothermal route. It exhibited the excellent electrocatalytic activity and stability for hydrogen evolution reaction. Image 1 • MoS 2 hollow nanospheres decorating Ni 3 S 2 nanowires by one-step hydrothermal route. • Extensive activity sites on MoS 2 hollow nanospheres and MoS 2 /Ni 3 S 2 interfaces. • Excellent HER activity (η = 85 mV at 10 mA cm−2 and η = 189 mV at 100 mA cm−2). [ABSTRACT FROM AUTHOR]

• Mo-CoS x active sites were confined in situ within MCM-41 for photocatalytic HER. • Co-MCM-41 can offer abundant Co sites to generate highly active Mo-CoS x sites. • Mo-CoS x active sites had greatly reduced size and enhanced dispersion on Co-MCM-41. • A high AQY of 12.3% at 520 nm was achieved by ErB-sensitized Mo-CoS x /MCM-41-100. Although transition-metal-based sulfides have been identified as efficient catalysts to replace expensive noble metal catalysts for photocatalytic H 2 evolution reaction (HER), their activities are still unsatisfied and could be further improved by controlling their microstructures and electronic structures. Herein, we present an effective strategy to confine highly active Mo-activated CoS x (Mo-CoS x) active sites within MCM-41 frameworks by sulfurization of Co-doped MCM-41 during the in situ photoreduction of [MoS 4 ]2- in Erythrosin B-triethanolamine (ErB-TEOA) system. It is found that Co-MCM-41 offers not only abundant coordinatively unsaturated Co sites to be activated by Mo and S but also large surface area to effectively disperse the in situ generated amorphous Mo-CoS x active sites. Under 520 nm irradiation, the most efficient Mo-CoS x /MCM-41-100 (Si/Co = 100) catalyst exhibits ~7, 3, and 4 times higher H 2 evolution activity than free MoS x , free Mo-CoS x , and CoS x /MCM-41-100, respectively, and an apparent quantum yield (AQY) of 12.3% for H 2 evolution. Furthermore, when Mo-CoS x /MCM-41-100 was sensitized with a more stable fluorescein (FL) dye, the photocatalytic system shows a sustainable H 2 evolution activity in a 20 h reaction, showing the good stability of Mo-CoS x /MCM-41-100 catalyst. This work provides a new insight into the design and development of highly active hybrid H 2 evolution catalysts based on transition metals for highly efficient and large-scale solar energy conversion to clean H 2 energy. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) are promising materials with fascinating properties. Their widespread applications are sometimes hindered by the intrinsic instability of frameworks. However, this instability of MOFs can also be exploited for useful purposes. Herein, we report the use of MOFs as metal ion precursors for constructing functional nanocomposites by utilizing the instability of MOFs. The heterogeneous growth process of nanostructures on substrates involves the release of metal ions, nucleation on substrates, and formation of a covering structure. Specifically, the synthesized CoS with carbon nanotubes as substrates display enhanced performance in a lithium‐ion battery. Such strategy not only presents a new way for exploiting the instability of MOFs but also supplies a prospect for designing versatile functional nanocomposites. [ABSTRACT FROM AUTHOR]

Zinc–cobalt double‐metal sulfides (ZCS) as Faradic electrode materials with high energy density have great potential for supercapacitors, but their poor transfer efficiency for electrons and ions hinders their electrochemical response. Herein, ZnCo2(CO3)1.5(OH)3@ZCS microflower hybrid arrays consisting of thin nanolayer petals were anchored on three‐dimensional graphene (ZnCo2(CO3)1.5(OH)3@ZCS/3DG) by a simple hydrothermal method and additional ion‐exchange process. A ZnCo2(CO3)1.5(OH)3@ZCS/3DG electrode delivered high capacitance (2228 F g−1 at 1 A g−1) and long cycling life (85.7 % retention after 17 000 cycles), which are ascribed to the multicomponent structural design. The 3DG conductive substrate improves the electron‐transfer dynamics of the electrode material. Meanwhile, the microflowers consisting of thin nanolayer petals could not only provide many active sites for ions to improve the capacitance, but also alleviate the volume expansion to ensure the structural stability. Furthermore, an all‐solid‐state asymmetric supercapacitor based on a ZnCo2(CO3)1.5(OH)3@ZCS/3DG electrode achieved a high energy density of 27 W h kg−1 at 528.3 W kg−1 and exhibits exceptional cyclic stability for 23 000 cycles. Its ability to light a blue LED for 9 min verified the feasibility of its application for energy storage devices. [ABSTRACT FROM AUTHOR]

Supported CoMoS and NiWS catalysts were synthesized on the basis of an Al2O3—SAPO-11 composite support. The acid and texture characteristics of the thus synthesized materials were examined. The morphologies of the active sulfide phase of the catalysts were compared. The kinetic properties of the supported sulfide catalysts in the reaction of hydroisomerization of n-hexadecane and in the hydroprocessing of the diesel fraction were examined. It was shown that it is possible to obtain hydrogenates with improved low-temperature properties in the presence of supported sulfide catalysts containing no noble metals. [ABSTRACT FROM AUTHOR]

In this article, the novel direct Z-scheme ZnIn2S4@BiOBr-(110) heterojunction structure was firstly synthesized via simple two-step hydrothermal method. The results of XRD and HRTEM indicated that as-prepared BiOBr mainly exposed high energy (110) facet. Simultaneously, the photoelectrochemical measurement was performed to further investigate the photo-induced carrier separation efficiency. The results indicated that Z-scheme heterojunction structure formed by the loading of ZnIn2S4 nanosheets not only promoted the separation of photogenerated carriers and inhibited fast recombination rate of photogenerated electron–hole pairs of pure BiOBr, but also endowed the composite with better redox activity. The degradation efficiency of RhB by BiOBr loaded with 10 mol% ZnIn2S4 has achieved 98% within 18 min under the irradiation of Xe lamp, which demonstrated that the unique direct Z-scheme ZnIn2S4@BiOBr-(110) composite photocatalytic materials has the potential application in environmental pollution control and energy conversion. [ABSTRACT FROM AUTHOR]

The development of high-performance anode materials for lithium-ion batteries is a critical aspect of advancing energy storage technology. This study presents a novel approach to improve the charge capacity of anodes by harnessing the reversible growth of the solid electrolyte interface (SEI). This work focuses on cobalt sulfide (Co 9 S 8) nanoparticles incorporated into a porous carbon nanotube (CNT) structure. Through a two-step pyrolysis process, Co 9 S 8 CNT composites, characterized by their conductive and mechanically robust CNT matrix are successfully synthesized. These Co 9 S 8 CNT anodes exhibit excellent initial charge capacity (560.5 mAh g−1 at 100 mA g−1) and remarkable stability, with a charge capacity of 633 mAh g−1 after 1000 cycles at 1000 mA g−1, accompanied by a Coulombic efficiency exceeding 99 %. Notably, this investigation reveals that the growth of the SEI plays a pivotal role in enhancing the charge capacity. Through in-situ Raman spectroscopy and other analytical techniques, it is suggested that the reversible reduction of organic solvent molecules within the large polymeric SEI is responsible for the increased charge capacity. This unique phenomenon is characterized by changes in the SEI's composition, driven by the charge and discharge processes. This study is a novel attempt to report a SEI's reversible growth that results in improved charge capacity, contrasting with prior research where SEI growth typically leads to capacity loss. Understanding this stable system provides valuable insights into increasing the cycle life and charge capacity of anodes, not only for transition metal sulfides but also for broader applications in energy storage. [ABSTRACT FROM AUTHOR]

In order to create sustainable, environmentally friendly energy systems, the Hydrogen Evolution Reaction and Oxygen Evolution Reaction must be prioritized. Transition metal sulfides (TMSs) have been studied extensively as catalysts for both HER and OER because of their high activity, cheap cost, and availability. However, its low stability and conductivity limit its usefulness. Recent research efforts have focused on developing TMS-based nanocomposites, which combine the advantageous properties of TMSs with those of other materials, in order to overcome these concerns. The latest advances in TMS-based nanocomposites for oxygen reduction reaction and hydrogen reduction reaction are outlined in this article. We begin by discussing the broad concepts of HER and OER and the problems of TMSs in these reactions. We have comprehensively addressed the role of Sulfur atoms in electrocatalytic water splitting. We also emphasize the need to improve the contact between TMSs and other materials to enable effective charge transfer. Lastly, we evaluate the performance of TMS-based nanocomposites in HER and OER and compare their activity to that of other cutting-edge catalysts. We also examine the remaining research problems and potential in this subject. TMS-based nanocomposites show significant potential for practical applications of HER and OER in renewable energy systems. [Display omitted] • The article focuses on the development of transition metal sulfide-based nanocomposites for efficient electrocatalytic water splitting to produce hydrogen fuel from water. • This review discusses the basic fundamentals of electrocatalytical water splitting. • The transition metal sulfide-based nanocomposites have great potential for use in electrocatalytic water splitting. • Future perspectives of TMSs as an efficient electrocatalysts are explained in detail. [ABSTRACT FROM AUTHOR]

Lithium-sulfur batteries are regarded as one of the most promising next-generation energy storage systems due to their high theoretical volumetric and high weight energy density. However, there are severe problems in the application of lithium-sulfur batteries. The shuttle effect of soluble lithium polysulfide (LiPs) and the low conductivity of sulfur, which leads to slow redox kinetics, are hindering the more significant application of lithium-sulfur batteries. One of the viable solutions to the cathode problem of lithium-sulfur batteries is heterostructured materials. The built-in electric field provided by the heterostructure can significantly accelerate the kinetics of charge transport. In this work, we constructed a heterogeneous structure of G-VS 4 /MoS 2 composites(PVM) modified by Polyvinylpyrrolidone(PVP) is constructed based on graphene, which consists of VS 4 nanosheets and MoS 2 nanosheets grown vertically on graphene lamellae. With weak van der Waals interactions, the one-dimensional (1D) chain-like VS 4 crystal structure enables fast charge transfer in Li-ion batteries. The two-dimensional (2D) lamellar MoS 2 crystals contain Mo-S bonds that also have adsorption effects on polysulfides. Density functional theory (DFT) calculations show that VS 4 and MoS 2 can increase the binding energy of the anode to the polysulfide. Therefore, the S@PVM cathode material provides a large capacity of 1061.4 mAh/g at 0.5 C and can still get to 808.3 mAh/g after 400th cycles. A capacity retention rate of 76.15% is obtained at the same time. It can also boast an initial discharge capacity of 834.8 mAh/g at 1 C. These works can provide more thoughts for developing cathode materials for lithium-sulfur batteries. • G-VS 4 /MoS 2 heterostructures composite was prepared by hydrothermal method modified by Polyvinylpyrrolidone(PVP). • The composite electrode achieves impressive initial capacity and long cycle stability at 0.5 C and 1 C. • The composite electrode can inhibit the shuttle effect effectively and achieve fast electrochemical reaction kinetics. • The composite electrode achieves long cycle stability with a high sulfur loading of 4.6 mg cm−2. [ABSTRACT FROM AUTHOR]

[Display omitted] • MS 2 (M = Fe, Ni, Co) have been synthesized by hydrothermal and calcining process. • First electrochemical comparison of MS 2 cathodes in Aluminum ion battery system. • CoS 2 had Co2+/Co3+ involved in charge compensation in addition to S 2 2−/S2−. • First-principles calculations revealed different Al ion storage mechanisms in MS 2. Transition metal dichalcogenides (TMDs) featured an open framework structure and versatile electronic properties are attractive for their higher capacitance when used as cathodes for aluminum-ion batteries (AIBs). However, the inexhaustive understanding of cell chemistry involving complicated charge transfer stalls the deployment of this type AIBs electrode materials. Here the sulfide materials of MS 2 (M = Fe, Ni, Co) served as emblematic conversion-type electrodes are taken as models to shed light on the regularity among the Al storage mechanisms in TMDs cathodes. To explain such chemistry, we therefore interrogate the redox mechanisms between MS 2 (M = Fe, Ni, Co) from a broad range of experimental and mechanistic characterization perspectives. Remarkably, as indicated by characterization results, the detailed Al insertion and removal processes occurring in MS 2 (M = Fe, Ni, Co) cathodes are revealed, accompanied by the anionic-redox reaction of sulfide anion (S2−), whereas the valence state transitions of the metal element in CoS 2 (Co2+∼Co3+) also occur simultaneously during the insertion/extraction of Al3+. Using theoretical calculations, we further clarify the essential reasons for the mechanistic discrepancy, and discuss the energy storage regularity in TMDs. These foundations not only contribute to a profound understanding for the charge storage mechanisms in TMDs but also expand the palette of property boosting electrode materials for practical AIBs. [ABSTRACT FROM AUTHOR]

Transition metal sulfides have recently captured the utmost attention as an energy storage device owing to their excellent electrochemical activity and conductivity. The amalgamation of carbonaceous materials along with transition metal sulfides was found to do wonders in the field of supercapacitors by amplifying the surface area, conductivity, capacitance, and stability of the active electrode material. In the present work microflower like CuS and CuS/C-dots composite was synthesized via the facile hydrothermal method. Numerous characterization techniques like XRD, SEM, TEM, XPS, and EDS were used to study the properties of the as-prepared samples. The CuS/C-dots composite as an active anode material exhibited an outstanding electrochemical performance with a superior specific capacitance of 2642 Fg−1 at a current density of 2 Ag−1. Furthermore, CuS/C-dots composite material displayed excellent capacitance retention of 58 % after 2000 cycles at a current density of 10 Ag−1. The superior charge transfer kinetics, unique structure, and conductivity of CuS/C-dots composite make it a remarkable material for electrochemical energy storage devices. [Display omitted] • CuS/C-dots microflowers were synthesized by one-step hydrothermal method. • The composites exhibited greater electrochemical performance than pristine CuS. • CuS/C-dots electrode displayed an outstanding specific capacitance of 2642 Fg−1 at 2 Ag−1. • Exceptional capacitance retention of 58 % after 2000 cycles at 10 Ag−1 and superior coulombic efficiency of 99.44 %. [ABSTRACT FROM AUTHOR]

[Display omitted] • The FeOOH-Co 9 S 8 heterostructure was prepared by a simple and stable synthetic method. • The FeOOH-Co 9 S 8 heterogeneous interface modulates the electronic structure of the Co site, facilitating the conversion of *O to *OOH and lowering the energy barrier of the OER reaction. • The obtained FeOOH-Co 9 S 8 composite electrode has excellent OER activity with an overpotential of 215 mV at a current density of 100 mA cm−2. The oxygen evolution reaction (OER) is a four-electron–proton coupling process with a high kinetic energy barrier, which affects the overall efficiency of water splitting. Rational construction of specific interfaces and optimization of electron interactions can effectively promote the kinetic behavior of OER. Herein, ultrathin FeOOH nanosheets were loaded on Co 9 S 8 nanorods by hydrothermal method to construct heterogeneous structures (FeOOH-Co 9 S 8 /NF), and the modulation of catalytic activity by structural changes in the phase interface region was investigated. FeOOH-Co 9 S 8 /NF showed excellent performance as an OER catalyst, requiring an overpotential of only 215 mV to reach 100 mA cm−2. The rich heterogeneous interface can optimize the coordination environment of the Co site by redistributing the interfacial charge to obtain the appropriate chemisorption strength of oxygen-containing intermediates. This paper explores the relationship between interfacial electronic structure changes and catalyst performance enhancement, and provides an experimental basis for further practicalization of OER catalysts. [ABSTRACT FROM AUTHOR]

A Mott–Schottky (MS) heterojunction of CoS 2 /NiS 2 embedded in a carbon matrix is successfully synthesized to form a high sodium storage CoS 2 /NiS 2 @C anode material for sodium-ion batteries. The underlying mechanism for performance enhancement are investigated by both in/ex-situ measurements and DFT calculations. This research has taken an important step towards the development of high-performance electrode materials for sodium-ion batteries. [Display omitted] • Carbon-matrix-embedded MS heterojunction of CoS 2 /NiS 2 is successfully prepared. • The as-prepared CoS 2 /NiS 2 @C exhibits exceptional sodium storage properties. • The mechanism is revealed by DFT calculations & i n/ex-situ characterizations. • The C-S bond promotes Na+ in the carbon matrix to migrate to embedded CoS 2 /NiS 2. • MS heterojunction in CoS 2 /NiS 2 accelerates electrochemical reaction kinetics. In this paper, carbon-matrix-embedded Mott–Schottky (MS) heterojunction of CoS 2 /NiS 2 (CoS 2 /NiS 2 @C) is prepared. The obtained CoS 2 /NiS 2 @C offers superior sodium storage performance such as large specific capacity (861.0 mAh/g at 2 A/g), extraordinary rate capability (649.2 mAh/g at 10 A/g, 371.4 mAh/g at 40 A/g) and excellent cycling stability (380.5 mAh/g after 3000 cycles at 10 A/g, and 298.5 mAh/g after 2000 cycles at 40 A/g). Electrochemical measurements and density functional theory (DFT) calculations as well as in/ex-situ characterization techniques are employed to reveal the underlying mechanisms. It is found that the outperforming sodium storage properties of CoS 2 /NiS 2 @C can be mainly attributed to the C-S bond and the MS heterojunction. The C-S bond formed at the interface between CoS 2 /NiS 2 and the carbon matrix promotes the migration of the sodium ions in the carbon matrix to the embedded CoS 2 /NiS 2 , while the MS heterojunction accelerates the electrochemical reaction kinetics of CoS 2 /NiS 2. Moreover, full-cell is assembled with CoS 2 /NiS 2 @C and Na 3 V 2 (PO 4) 3 /C to validate the practical application of CoS 2 /NiS 2 @C. The full-cell achieves both high specific capacity and outstanding rate performance, demonstrating the great application potential of such CoS 2 /NiS 2 @C anode in high-performance sodium-ion batteries. [ABSTRACT FROM AUTHOR]

Porphyrins, corrins, and tetrapyrroles constitute macrocycles in essential biomolecules such as heme, chlorophyll, cobalamin, and cofactor F430. The chemical synthesis as well as the enzymatic synthesis of these macrocycles starts from pyrrole derivatives. We here show that pyrrole and dimethyl pyrrole can be formed under the simulated volcanic, hydrothermal conditions of Early Earth, starting from acetylene, propyne, and ammonium salts in the presence of NiS or CoS as catalysts.

Supercapacitors (SCs) have been regarded as alternative electrochemical energy storage devices; however, optimizing the electrode materials to further enhance their specific energy and retain their rate capability is highly essential. Herein, the influence of nitrogen content and structural characteristics (i.e., porous and non-porous) of the NiS/nitrogen-doped carbon nanocomposites on their electrochemical performances in an alkaline electrolyte is explored. Due to their distinctive surface and the structural features of the porous carbon (A-PVP-NC), the as-synthesized NiS/A-PVP-NC nanocomposites not only reveal a high wettability with 6 M KOH electrolyte and less polarization but also exhibit remarkable rate capability (101 C/g at 1 A/g and 74 C/g at 10 A/g). Although non-porous carbon (PI-NC) possesses more nitrogen content than the A-PVP-NC, the specific capacity output from the latter at 10 A/g is 3.7 times higher than that of the NiS/PI-NC. Consequently, our findings suggest that the surface nature and porous architectures that exist in carbon materials would be significant factors affecting the electrochemical behavior of electrode materials compared to nitrogen content.

The tetracarbonyl complexes of transition metal chalcogenides M 2 X 2 (CO) 4 , where M = Fe, Co, Ni, Cu and X = S, Se, are examined by density functional theory (DFT). The M 2 X 2 core is cyclic with either planar or non-planar geometry. As a sulfide, it is present in natural enzymes and has a selective redox capacity. The reduced forms of the selenide and sulfide complexes are relevant to the hydrogen evolution reaction (HER) and they provide different positions of hydride ligand binding: (i) at a chalcogenide site, (ii) at a particular cation site and (iii) in a midway position forming equal bonds to both cation sites. The full pathway of water decomposition to molecular hydrogen and oxygen is traced by transition state theory. The iron and cobalt complexes, cobalt selenide, in particular, provide lower energy barriers in HER as compared to the nickel and copper complexes. In the oxygen evolution reaction (OER), cobalt and iron selenide tetracarbonyls provide a low energy barrier via OOH* intermediate. All of the intermediate species possess favorable excitation transitions in the visible light spectrum, as evidenced by TD-DFT calculations and they allow photoactivation. In conclusion, cobalt and iron selenide tetracarbonyl complexes emerge as promising photocatalysts in water splitting.

With the rapid improvement of compact smart devices, fabricating anode materials with high volumetric capacity has gained substantial interest for future sodium-ion batteries (SIBs) applications. Herein, a novel bimetal sulfide CuCo 5 S 8 material is proposed with enhanced volumetric capacity due to the intrinsic metallic electronic conductivity of the material and multi-electron transfer during electrochemical procedures. Due to the intrinsic metallic behavior, the conducting additive (CA) could be removed from the electrode fabrication without scarifying the high rate capability. The CA-free CuCo 5 S 8 electrode can achieve a high volumetric capacity of 1436.4 mA h cm -3 at a current density of 0.2 A g -1 and 100 % capacity retention over 2000 cycles in SIBs, outperforming most metal chalcogenides, owing to the enhanced electrode density. Reversible conversion reactions are revealed by combined measurements for sodium systems. The proposed new strategy offers a viable approach for developing innovative anode materials with high-volumetric capacity., (© 2023 Wiley-VCH GmbH.)

Here we present a perspective on in-situ studies of high temperature batteries. We focus on a primary battery technology- the thermal battery- which possesses a molten salt electrolyte. We discuss aspects of sample environment design, data collection and will briefly look at some case studies. We aim to highlight the importance of using in-situ techniques in studying electrochemical devices such as high temperature batteries.

Thiophene was detected on Mars during the Curiosity mission in 2018. The compound was even suggested as a biomarker due to its possible origin from diagenesis or pyrolysis of biological material. In the laboratory, thiophene can be synthesized at 400 °C by reacting acetylene and hydrogen sulfide on alumina. We here show that thiophene and thiophene derivatives are also formed abiotically from acetylene and transition metal sulfides such as NiS, CoS and FeS under simulated volcanic, hydrothermal conditions on Early Earth. Exactly the same conditions were reported earlier to have yielded a plethora of organic molecules including fatty acids and other components of extant metabolism. It is therefore tempting to suggest that thiophenes from abiotic formation could indicate sites and conditions well-suited for the evolution of metabolism and potentially for the origin-of-life on extraterrestrial planets.