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Carbon nanotubes supported cobalt nickel sulphide nanoparticles (nano-NiCo2S4@CNTs) were successfully prepared by a hydrothermal method as heterogeneous catalyst which can be used as an activator of peroxymonosulphate (PMS) for the degradation of chloroquine phosphate (CQP). Based on characterisation techniques, the prepared catalyst has excellent surface properties and structural stability. When different concentrations of CQP were treated with 0.2 g/L nano-NiCo2S4@CNTs and 1.0 mM PMS, the highest degradation rate could reach 99.86% after 30 min. Under the interference of pH, common anions and humic acid in the water environment, the reaction system can still achieve high degradation efficiency, showing excellent anti-interference ability and practical applicability. Furthermore, in the nano-NiCo2S4@CNTs/PMS system, according to the identification results of reactive oxygen species, the free radical and non-free radical pathway are responsible for the degradation of CQP, and the PMS mechanism activation was comprehensively proposed. Twelve intermediate products were detected in the degradation process, and the possible degradation pathways of CQP were proposed. This toxicity analysis demonstrates that the intermediate products formed during CQP degradation pose lower environmental risks compared to the original pollutant. In addition, after using the catalyst four cycles, the removal efficiency of CQP remains above 80%, indicating the excellent reusability and low metal ion leaching characteristics. Therefore, the nano-NiCo2S4@CNTs synthesised in this research has broad application prospects in activating PMS for wastewater treatment. [ABSTRACT FROM AUTHOR]

Regulating the adsorption of an intermediate on an electrocatalyst by manipulating the electron spin state of the transition metal is of great significance for promoting the activation of inert nitrogen molecules (N2) during the electrocatalytic nitrogen reduction reaction (eNRR). However, achieving this remains challenging. Herein, a novel 2D/2D Mott–Schottky heterojunction, Co9S8/Nb2CTx‐P, is developed as an eNRR catalyst. This is achieved through the in situ growth of cobalt sulfide (Co9S8) nanosheets over a Nb2CTx MXene using a solution plasma modification method. Transformation of the Co spin state from low (t2g6eg1) to high (t2g5eg2) is achieved by adjusting the interface electronic structure and sulfur vacancy of Co9S8/Nb2CTx‐P. The adsorption ability of N2 is optimized through high spin Co(II) with more unpaired electrons, significantly accelerating the *N2→*NNH kinetic process. The Co9S8/Nb2CTx‐P exhibits a high NH3 yield of 62.62 µg h−1 mgcat.−1 and a Faradaic efficiency (FE) of 30.33% at −0.40 V versus the reversible hydrogen electrode (RHE) in 0.1 m HCl. Additionally, it achieves an NH3 yield of 41.47 µg h−1 mgcat.−1 and FE of 23.19% at −0.60 V versus RHE in 0.1 m Na2SO4. This work demonstrates a promising strategy for constructing heterojunction electrocatalysts for efficient eNRR. [ABSTRACT FROM AUTHOR]

Nanostructured materials incorporating transition metal sulfides have demonstrated considerable potential across various applications, particularly in the realms of energy production and storage. Sulfide-based material preparation is a challenging and costly procedure that requires a high temperature and reducing atmosphere. This work reports that manganese cobalt sulfide (MCS) and reduced graphene oxide composite manganese cobalt sulfide (rMCS) were successfully prepared through a hydrothermal method. Various characterization techniques were employed to analyze the prepared materials, including X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, Brunauer-Emmett-Teller analysis, and X-ray photoelectron spectroscopy. In a three-electrode system, MCS and rMCS electrodes exhibit an excellent specific capacitance of 1695 and 1925 F g−1 at 1 A g−1 current density respectively. MCS delivers the capacitance retention of 99% and rMCS exhibits the capacitance retention of 100% capacitance retention over 5000 consecutive cycles. The constructed asymmetric supercapacitor electrode (rMCS//rGO) exhibits the energy and power density of 64 Wh kg−1 at 799 W kg−1, respectively with outstanding cyclic stability of 97.4% even after 10,000 cycles. The exceptional electrochemical properties of MCS with rGO composite electrode indicate that they would make an outstanding electrode material for cutting-edge energy storage devices. [ABSTRACT FROM AUTHOR]

Defects and microstructures have been utilized to effectively modulate electromagnetic (EM) wave absorption for mitigating electromagnetic pollution and stealth issues. However, precisely feasibly tailoring them still remains challenging. Here, by using a multilevel hollow cobalt sulfide embedded in a heteroatomic sulfur (S) ‐doped carbon aerogel, a preferential reaction strategy of modulating point defects and hollow microstructures via controllable S atoms migration is proposed to improve the EM wave absorption. S atoms contribute to the creation of hollow structures via Kirkendall effects, as well as inducing point defects in the carbon lattice through doping. More significantly, the mechanisms prioritizing the formation of hollow structures over defects have been discovered, with low‐velocity atomic migration primarily modulating the microstructure for interfacial polarization and impedance matching, and high‐velocity atom migration focused on introducing defects to achieve polarization and conductive loss. The resulting aerogel exhibits an exceptionally maximum reflection loss of −52.82 dB and an effective absorption bandwidth of 8.82 GHz, which far exceeds most of the currently reported materials. Experimental and theoretical approaches, including microwave heating, Tesla interaction, first principles, and far‐field simulation, are comprehensively employed to verify its absorption effect and mechanism. Furthermore, the combination of excellent infrared stealth and self‐cleaning properties opens up its potential applications in complex environments. [ABSTRACT FROM AUTHOR]

Nickel–cobalt sulfide is a promising material for supercapacitor positive electrodes due to its high theoretical capacitance. Herein, the electrochemical properties of nickel–cobalt sulfide nanostructures synthesized via a two‐stage hydrothermal method are investigated and the synthesis conditions to achieve high mass loading while maintaining high specific capacitance are determined. The nanostructural morphology and effective mass loading of the electrodes (≈10 mg cm−2) enable the achievement of a high specific capacitance value of 8.1 F cm−2 at a current density of 5 mA cm−2. A hybrid capacitor is made using optimized nickel–cobalt sulfide electrodes as the positive electrode and activated carbon as the negative electrode. The device exhibits a maximum operation potential window of 1.75 V and an energy density of 51.2 Wh kg−1 at a power density of 262.5 W kg−1. Electrochemical measurements demonstrate that the device maintains a capacitance retention rate of 95% after 10 000 charge–discharge cycles within a working voltage of 1.8 V. High electrochemical performances compared with others devices‐based water electrolytes make it promising for the energy storage device. [ABSTRACT FROM AUTHOR]

We herein report successful syntheses of both nickel cobalt sulfide (NCS) and its composite with zeolite (NCS@Z) using a solvothermal method. Techniques such as EDX analysis, SEM, and molar ratio determination were used for product characterization. The incorporation of NCS significantly changed the surface roughness and active sites of the zeolite, improving the efficiency of methylene blue degradation and its reusability, especially under UV irradiation. In comparing the pseudo-first order rates, the highest degradation efficiency of methylene blue was achieved with NCS-2@Z, having a degradation extent of 91.07% under UV irradiation. This environmentally friendly approach offers a promising solution for the remediation of methylene blue contamination in various industries. [ABSTRACT FROM AUTHOR]

The development of efficient and durable catalysts for the hydrogen evolution reaction (HER) is essential for sustainable energy research. Cobalt sulfides (CoSx) have attracted significant interest as prospective catalysts for the HER owing to their promising catalytic activity and high stability. In this study, CoSx nanocrystals embedded in nitrogen-doped carbon frameworks (NC) are fabricated using a zeolite imidazole framework precursor via a two-step pyrolysis-sulfurization process, followed by combination with carbon black (CB) to create CoSx-NC/CB as an efficient electrocatalyst for the HER. Interestingly, this catalyst displays a higher HER activity than that of the investigated materials, with an overpotential of 282 mV at a current density of 10 mA cm− 2, along with a Tafel slope of 57.6 mV dec− 1 in an acidic solution. This performance is attributed to the synergistic effect of CoSx nanoparticles, nitrogen-doped carbon, and highly conductive CB, which improves the number of active sites, electron transfer, and electrochemical surface area. This outcome has significant potential for the development of economically viable catalysts for water splitting. [ABSTRACT FROM AUTHOR]

[Display omitted] Developing an efficient, robust, and noble metal-free electrocatalyst that can catalyse oxygen evolution reactions (OER) remains a significant challenge. CoS 2 , a representative of pyrite form transition metal dichalcogenides, has recently been identified as an economical catalyst. Here, an incredibly quick and scalable technique for novel catalysts synthesized with the use of the microwave method was introduced. Manganese-doped cobalt sulphide (Mn-CoS 2) showed outstanding OER with a very low overpotential of 227 mV at 10 mA cm−2. Exposure of surface atoms resulted in high electrochemical activity, where the defects facilitated charge and mass transfer along the nanostructure, allowing surface dependent electrochemical reactions to be performed more efficiently. The electronic properties of pristine and transition-metal-doped CoS 2 structures were also investigated using density functional theory (DFT). To better understand transition metal's dependent impact on crystal structure, orbital electronic participation, charge density, and charge transformation in both pristine and Mn-doped CoS 2 frameworks were calculated and analysized. Our synthesis approach is primarily commercial and extensible, overcoming synthesis challenge of transition metal sulphide nanostructures with prime quality and implying a potential for commercial uses. [ABSTRACT FROM AUTHOR]

The pursuit of sustainable and efficient energy storage solutions has driven extensive research into advanced electrode materials for pseudocapacitors. In this work, manganese cobalt sulfide (MnCo2S4) and reduced graphene oxide (rGO) were synthesized hydrothermally. The presence of functional groups in crumpled sheet-like rGO having high surface area enhanced the charge storage ability. The existence of multiple oxidation states in MnCo2S4 accounts for the faradic process on the electrode surface. MnCo2S4 and rGO exhibit a specific capacitance of 414 F/g and 588 F/g at the scan rate of 5 mV/s with the faradic dominating behavior in 6 M potassium hydroxide electrolyte. Non-linear charge–discharge curves with plateaus denoted the voltage range for the occurrence of redox reaction. Low charge transfer resistance and solution resistance were observed along with Warburg diffusion resistance in impedance measurements. An asymmetric configuration of electrode containing anode, cathode, separator, and electrolyte was constructed to check the practical relevancy. [ABSTRACT FROM AUTHOR]

[Display omitted] Tubular Co 9 S 8 /CdS heterostructures have been successfully synthesized by in-situ growing CdS onto Co 9 S 8 nanotubes through a simultaneous immobilization and in-situ reduction strategy. It turned out that the so-obtained heterostructure with Co 9 S 8 /CdS molar ratio of 1/10 can display a broad light absorption edge and especially much enhanced capacity for photocatalytic reduction of Cr(VI) under visible light. The characterization analysis and experimental results suggested that an interfacial electrostatic field between Co 9 S 8 and CdS elements in the heterostructure could be constructed due to their different Fermi levels, allowing for more quantities of highly reductive electrons to participate in the photocatalytic reaction. Therefore, the so-obtained Co 9 S 8 /CdS (1/10) heterostructures could achieve the photocatalytic reduction efficiency of 100% within 20 min, which was more than two and four times larger than that of pristine CdS and Co 9 S 8 , respectively. Moreover, the possible photocatalytic reaction mechanism for reducing Cr(VI) was investigated and found to follow the direct Z-scheme charge transfer pathway. This novel fabrication route for composite photocatalysts with tubular heterostructures could lead to the widespread implementations for the elimination of various harmful pollutants in the process of environmental governance. [ABSTRACT FROM AUTHOR]

[Display omitted] Exploring precious metal-free bifunctional electrocatalysts for both the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) is essential for the practical application of rechargeable Zn-air battery (ZAB). Herein, Ni-doped Co 9 S 8 nanoparticles embedded in a defect-rich N, S co-doped carbon matrix (d-Ni x Co 9-x S 8 @NSC) are synthesized via a facile pyrolysis and acid treatment process. The introduction of abundant defects in both the carbon matrix and metal sulfide provides numerous active sites and significantly enhances the electrocatalytic performances for both the ORR and OER. d-Ni x Co 9-x S 8 @NSC exhibits a superior half-wave potential of 0.841 V vs. RHE for the ORR and delivers a low overpotential of 0.329 V at 10 mA cm−2 for the OER. Additionally, Zn-air secondary battery using d-Ni x Co 9-x S 8 @NSC as the air cathode displays a higher specific capacity of 734 mAh g Zn −1 and a peak power density of 148.03 mW cm−2 compared to those of state-of-the-art Pt/C-RuO 2 (673 mAh g Zn −1 and 136.9 mW cm−2, respectively). These findings underscore the potential of d-Ni x Co 9-x S 8 @NSC as a high-performance electrocatalyst for secondary ZABs, offering new perspectives on the design of efficient noble metal-free electrocatalysts for future energy storage and conversion applications. [ABSTRACT FROM AUTHOR]

A facile cation modulation strategy is proposed for the synthesis of copper/cobalt bimetallic sulfides dispersed on hierarchical carbon nanoflowers, which exhibit excellent oxygen electrocatalysis capacity to drive electrochemiluminescence for cytosensing. [ABSTRACT FROM AUTHOR]

Electrolysis of water integrated with the renewable energy as input source can contribute significantly in the production of green hydrogen, a clean and versatile energy carrier. In water electrolyzer, the hydrogen evolution reaction (HER) at the cathode must act synchronously with the oxygen evolution reaction (OER) at the anode to effectively accomplish total water-splitting. The performance of an electrolyzer is often limited by the low performance of anode and it is important to develop an electrocatalyst which can efficiently perform both HER and OER. Ni and Fe based layered-double-hydroxides (LDHs) have gained a lot of interest owing to their outstanding OER electrocatalytic activity, however they are known to have poor HER performance. To enhance the overall water splitting efficiency of the LDHs, we present a simple approach of preparing a heterojunction of LDH with cobalt sulphide. The bifunctional electroactivity of the designed electrocatalyst Co 3 S 4 @Ex.NiFe-LDH, worked efficiently in both HER and OER electrocatalysis. Chalcogenides known for HER, not only improves the HER performance of the composites but also found to reduce the charge transfer resistance. Obtained results showed that when it comes to the OER performance, the recommended catalyst shadows the state of art catalyst RuO 2. Additionally, the catalyst has outstanding activity and stability, achieving a current density of around −120 mA/cm2 over a six-day period. The electrolyzer composed of both anode and cathode designated as Co 3 S 4 @Ex.NiFe-LDH||Co 3 S 4 @Ex.NiFe-LDH only needs a low voltage input of 1.49 V to achieve a total water splitting reaction at required current density of 10 mA/cm2, showing efficacy at the low voltage input. Experimental observations showed Co 3 S 4 @Ex.NiFe-LDH performs better than Pt/C–RuO 2 in alkaline water electrolysis. The electrolyzer can continuously produce hydrogen at 50 mA/cm2 for more than a week period; indicating its potential for long-term application. [Display omitted] • Synthesis of Co 3 S 4 @Ex.NiFe-LDH electrocatalyst by a simple solvothermal technique. • Co 3 S 4 @Ex.NiFe-LDH excels in OER, surpassing the state-of-the-art catalyst RuO 2. • Stable HER performance with minimum degradation over long period. • Co 3 S 4 @Ex.NiFe-LDH.||Co 3 S 4 @Ex.NiFe-LDH performs better than standard Pt/C–RuO 2 configuration • For eight days, Co 3 S 4 @Ex.NiFe-LDH.||Co 3 S 4 @Ex.NiFe-LDH continually produced 50 mAcm−2 [ABSTRACT FROM AUTHOR]

Phase control over cation exchange (CE) reactions has emerged as an important approach for the synthesis of nanomaterials (NMs), enabling precise determination of their reactivity and properties. Although factors such as crystal structure and morphology have been studied for the phase engineering of CE reactions in NMs, there remains a lack of systematic investigation to reveal the impact for the factors in heterogeneous materials. Herein, we report a molybdenum disulfide induced phase control method for synthesizing multidimensional Co3S4‐MoS2 heteronanostructures (HNs) via cation exchange. MoS2 in parent Cu1.94S‐MoS2 HNs are proved to affect the thermodynamics and kinetics of CE reactions, and facilitate the formation of Co3S4‐MoS2 HNs with controlled phase. This MoS2 induced phase control method can be extended to other parent HNs with multiple dimensions, which shows its diversity. Further, theoretical calculations demonstrate that Co3S4 (111)/MoS2 (001) exhibits a higher adhesion work, providing further evidence that MoS2 enables phase control in the HNs CE reactions, inducing the generation of novel Co3S4‐MoS2 HNs. As a proof‐of‐concept application for crystal phase‐ and dimensionality‐dependent of cobalt sulfide based HNs, the obtained Co3S4‐MoS2 heteronanoplates (HNPls) show remarkable performance in hydrogen evolution reactions (HER) under alkaline media. This synthetic methodology provides a unique design strategy to control the crystal structure and fills the gap in the study of heterogeneous materials on CE reaction over phase engineering that are otherwise inaccessible. [ABSTRACT FROM AUTHOR]

Designing efficient electrode materials is necessary for supercapacitors but remains highly challenging. Herein, cobalt sulfide with crystalline/amorphous heterophase (denoted as Co(Al)S) derived from an Al metal–organic framework was constructed by ion exchange/acid etching and subsequent sulfidation strategy. It was found that rational sulfidation by adjusting the sulfur source concentration to a suitable level was favorable to form a 3D nanosheet-interconnected network architecture with a large specific surface area, which promoted ion/electron transport and charge separation. Benefiting from the features of the unique network structure and heterophase accompanied by aluminum, nitrogen and carbon coordinated in amorphous phase, the optimal Co(Al)S(10) exhibited a high specific capacity (1791.8 C g−1 at 1 A g−1), an outstanding rate capability and an excellent cycling stability. Furthermore, the as-assembled Co(Al)S//AC device afforded an energy density of 72.3 Wh kg−1 at a power density of 750 W kg−1, verifying that the Co(Al)S was a promising material for energy storage devices. The developed scheme is expected to promote the application of MOF-derived electrode materials in electrochemical energy storage and conversion fields. [ABSTRACT FROM AUTHOR]

Electrochemical water splitting offers a promising avenue for producing clean hydrogen fuel, essential for a sustainable energy landscape. A highly efficient catalyst, featuring a one-dimensional structure, has been synthesized by combining zinc iron sulfide with molybdenum disulfide (ZFSMS) on a nickel foam substrate. This synthesis method utilizes a simple yet effective hydrothermal approach tailored for efficient water splitting. By carefully engineering the interface between zinc iron sulfide and molybdenum disulfide, the electronic conductivity of the catalyst is significantly boosted, enhancing its catalytic performance. The resulting hybrid, ZFSMS, exhibits remarkable electrocatalytic efficiency with minimal overpotentials. Specifically, overpotentials of 130 mV and 220 mV are recorded for the oxygen evolution reaction at 20 mA cm−2 and 50 mA cm−2, respectively. Moreover, for the hydrogen evolution reaction, overpotentials of 145 mV and 257 mV are observed at 10 mA cm−2 and 40 mA cm−2, respectively, in a 1.0 M potassium hydroxide solution. Notably, the ZFSMS-based electrolyzer operates at a low voltage of 1.5 V at 10 mA cm−2, underscoring its efficiency in facilitating electrochemical hydrogen generation. This catalyst good candidate for advancing green hydrogen production, contributing to the progress of sustainable and clean hydrogen fuel production methods. [Display omitted] • A highly efficient catalyst, characterized by a one-dimensional morphology and structure, has been developed. • The overpotentials are measured for the oxygen evolution reaction at 20, and 50 mA cm−2. • The hydrogen evolution reaction, the overpotentials are 145 mV and 257 mV at 10, and 40 mA cm−2. • The zinc cobalt sulfide and molybdenum disulfide (ZFSMS), demonstrates remarkable electrocatalytic activity with low overpotentials. [ABSTRACT FROM AUTHOR]

Cobalt sulfide, a class of metal chalcogenide with tunable electronic structure and component distribution, has attracted considerable interest in renewable energy conversion and utilization. In this work, we report a facile, efficient and scalable method to synthesize Co9S8 supported on nitrogen and sulfur co doped porous carbon (Co9S8/N,S‐PC) hybrid from the annealing treatment of a coordination compound assembled by 2‐mercaptobenzimidazole, 4,4‐bipyridine and cobalt salt. The heteroatom of organic ligand could efficiently tune the electronic properties of Co9S8 nanoparticles and well‐designed carbon. Meanwhile the interaction of organic ligands provides a platform for the high dispersion of Co9S8. Owing to the synergetic effect, the Co9S8/N,S‐PC catalyst shows an admirable oxygen reduction reaction (ORR) activity with the E1/2 of 0.804 V vs. RHE, together with good durability, and tolerance to methanol poisoning in alkaline media. [ABSTRACT FROM AUTHOR]

P204 was used to extract copper and cobalt from low concentration cobalt sulphide concentrate leaching solution. The effects of pH of extraction solution, extractor concentration, extraction ratio and time on the extraction efficiency were investigated. The results show that under the conditions of pH = 4, P204 volume fraction of 25 %, extraction ratio VO/VA = 1/1, extraction time of 3 min, reverse extractant sulfuric acid concentration of 0.10 mol/L, and reverse extraction ratio VO/VA = 2/1, the test of two-stage countercurrent extraction, four-stage countercurrent stripping is carried out on the purified liquid of cobalt sulfide concentrate, the mass concentration of cobalt and copper in the raffinate is 338.80 mg/L and 2.96 mg/L, the extraction rate of copper is 98.32%, and 90.03% of cobalt remains in the water phase. Copper and cobalt can be effectively further separated by stripping, which is conducive to preparation of high purity cobalt sulfate. [ABSTRACT FROM AUTHOR]

In recent years, cobalt sulfide has become a potential electrode material due to its considerable theoretical capacitance and high conductivity. However, its agglomerate susceptibility and structural instability during the charging/discharging process have impeded its widespread application. Herein, we synthesize Co9S8/MXene nanohybrids using a straightforward one-step solvothermal method, employing MXene nanosheets as a conducting substrate. The strong interfacial interaction of both phases is exploited to efficiently alleviate the above problems. Furthermore, a metal-doped strategy has been adopted to modulate the composition and the structure of the nanocomposites, which could expose more redox active sites and considerably improve the redox kinetics. The obtained Al–Co9S8/MXene material has a remarkable electrical conductivity and excellent charge/discharge performance, with the specific capacitance up to 1657.33 F g−1 at 2 A g−1 and a superior rate capability of 75% retention even at 12 A g−1. This strategy not only provides an efficient method for synthetic anode electrode materials but also offers ideas for the development of materials more suitable for industrial applications. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) sulfide-based transition metal dichalcogenides (TMDs) have shown their crucial importance in energy storage devices. In this study, the tungsten disulfide (WS2) nanosheets were combined with hydrothermally synthesized cobalt magnesium sulfide (CoMgS) nanocomposite for use as efficient electrodes in supercapattery energy storage devices. The characteristics of the WS2@CoMgS nanocomposite were better than those of the WS2 and CoMgS electrodes. XRD, SEM, and BET analyses were performed on the nanocomposite to examine its structure, morphology, and surface area in depth. In three-electrode assemblies, the composite (WS2@CoMgS) electrode showed a high specific capacity of 874.39 C g−1 or 1457.31 F g−1 at 1.5 A g−1. The supercapattery device (WS2@CoMgS//AC) electrode demonstrated a specific capacity of 325 C g−1 with an exceptional rate capability retention of 91% and columbic efficiency of 92% over 7000 cycles, according to electrochemical studies. Additionally, the high energy storage capacity of the WS2@CoMgS composite electrode was proved by structural and morphological investigations. [ABSTRACT FROM AUTHOR]

Supercapattery, an energy harvesting device that combines key characteristics of supercapacitors and rechargeable batteries, has demonstrated excellent electrochemical performance due to its exceptional cycle stability and high power and energy densities. The hydrothermal synthesis of a CoMgS/ZnO composite was performed in this investigation, which enabled the evaluation of its electrochemical and structural properties. The specific capacity of the cobalt magnesium sulphide (CoMgS) nanocomposite electrode material experienced a substantial increase from 510 to 998 C g−1 at 5 mV s−1 when ZnO was added. This improvement resulted from the addition of ZnO, which increased conductivity and enhanced redox active sites. A supercapattery device has demonstrated a remarkable specific capacity of 398 C g−1 at 2 A g−1. Furthermore, it exhibits an exceptional power density of 2653.88 W kg−1 and a noteworthy energy density of 36.18 Wh kg−1. Even after subjecting the hybrid device to 5000 GCD cycles, it retained an impressive 96.84% of its initial capacity. Besides, the electrode material is also used for the photochemical activity. The findings offer substantial guidance for designing electrodes from nanocomposite-related materials for supercapattery, and they also support the stability and functionality of energy storage devices. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fe and F dual-doped CoS 2 are prepared by anion exchange and heat treatment process. • Dual doping strategy increases reaction kinetics and intrinsic catalytic activity. • Uniform hollow structure enhances the number of exposed active sites for OER. • DFT calculation reveal that the dual-dopants modifies energy states during the OER. Utilizing renewable electricity for water electrolysis offers a promising way for generating high-purity hydrogen gases while mitigating the emission of environmental pollutants. To realize the water electrolysis, it is necessary to develop highly active and precious metal-free electrocatalyst for oxygen evolution reaction (OER) which incurs significant overpotential due to its complicated four-electron transfer mechanism. Hence, we propose a facile preparation method for hollow-structured Fe and F dual-doped CoS 2 nanosphere (Fe-CoS 2 -F) as an efficient OER electrocatalyst. The uniform hollow and porous structure of Fe-CoS 2 -F enlarge the specific surface area and increase the number of exposed active sites. Furthermore, the Fe and F dual-dopants synergistically contributed to the adjustment of electronic structure, thereby promoting the adsorption/desorption of oxygen-containing reaction intermediates on active sites during the alkaline OER procedure. As a result, the prepared Fe-CoS 2 -F exhibits outstanding OER activity, characterized by a low overpotential of 298 mV to achieve a current density of 10 mA cm−2 and a Tafel slope as small as 46.0 mV dec−1. Based on computational theoretical calculations, the introduction of the dual-dopants into CoS 2 structure reduce the excessively strong adsorption energy of reaction intermediate in the rate determining step, leading to effectively promoted electrocatalytic cycle for OER in alkaline environment. This study presents an effective strategy for preparing noble metal-free OER electrocatalysts with promising potential for large-scale industrial water electrolysis. [ABSTRACT FROM AUTHOR]

Cobalt is a critical metal widely distributed in nature, but cobalt ore has hardly been found as an independent mineral. Cobalt-bearing pyrite tailings separated from iron ore is one of the resources for recovering cobalt. In the following study, roasting is carried out to oxidize cobalt-bearing pyrite tailings for preparing and recovering the cobalt by acid leaching. The further aim of the research is to determine and control the optimal technological regime for roasting by using thermodynamic modeling. The phase transition in Fe–S–O and Co–S–O systems and its mechanism are analyzed under the partial pressure of oxygen and sulfur dioxide at constant temperatures. Thermodynamic modeling proves that iron and cobalt sulfides can be intensively oxidized at a relatively high temperature (>900 °C) under an atmosphere of logp(O2) > −5, leading to the formation of SO2 (logp(SO2) < 0). The results of the roasting experiment indicate 98% desulfurization degree upon holding for about 4–5 h and at > 1000 °C. Based on these thermodynamic modeling and experimental results, the roasting of cobalt containing pyrite can be optimized with substantial productivity with regard to the metal oxide and cobalt thereof. Oxidative roasting also allows the elimination of environmentally hazardous gases such as sulfur during the process. [ABSTRACT FROM AUTHOR]

BACKGROUND: Fabricating high‐performance bifunctional electrocatalysts remains challenging to promote the development of electrocatalytic water‐splitting. RESULT: A heterostructure Fe‐Ni3S2@CoSx/NF was successfully synthesized using an interfacial engineering strategy. Benefiting from the strong synergistic effect between highly active cobalt sulfide (CoSx) and iron‐doped trinickel‐disulfide (Ni3S2) (Fe‐Ni3S2), Fe‐Ni3S2@CoSx/NF exhibited outstanding bifunctional performance, with low overpotentials of 77 and 217 mV for the cathodic hydrogen evolution reaction (HER) and anodic oxygen evolution reaction (OER), respectively, at 10 mA cm−2. CONCLUSION: The CoSx nanoarrays and Fe‐Ni3S2 nanosheets respectively served as HER and OER active centers. When Fe‐Ni3S2@CoSx/NF was used as both cathode and anode for overall water‐splitting, a low voltage of 1.52 V was required to reach the current density of 10 mA cm−2 with nearly 100% Faradic efficiency and outstanding durability. © 2024 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

The rational design of a core-shell structured electrocatalyst is important to improve the efficiency of electrocatalytic hydrogen production through water splitting. Herein, the catalyst is composed of rhenium disulfides (ReS 2) vertically grown on cobalt sulfides/carbon hybrid by hydrothermal and activation treatment (CoS 2 –C@ReS 2 /CFP). The core-shell structure is constructed by sulfurizing the cobalt-based metal-organic framework, preventing the restacking of the ReS 2 nanosheet, exposing more active sites, and facilitate electrolyte ion diffusion. Moreover, the CoS 2 –C@ReS 2 /CFP catalyst shows exceptional performance during the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) process in an alkaline electrolyte. At ·10 mA cm−2, the overpotentials of the CoS 2 –C@ReS 2 /CFP catalyst are 85 and 257 mV during the HER and OER processes with the small Tafel slope, low charge transfer resistance and exceptional catalytic stability. The combination of the CoS 2 core and ReS 2 shell is designed to adjust the adsorption energy of water molecules, promoting water dissociation, and enhancing the catalytic activity of CoS 2 –C@ReS 2 /CFP catalyst. This work provides an efficient strategy for developing the core-shell structured catalysts, potentially advancing the practical application into water splitting for hydrogen production. • The core-shell CoS 2 –C@ReS 2 heterostructure was synthesized by hydrothermal method. • The ReS 2 nanosheets are uniformly distributed on CoS 2 surface without any aggregation. • CoS 2 –C@ReS 2 heterostructure shows exceptional catalytic performance. • The boosted active sites are confirmed by density functional theory. [ABSTRACT FROM AUTHOR]

Metal‐based chalcogenides exhibit great promise for overall water splitting, yet their intrinsic catalytic reaction mechanisms remain to be fully understood. In this work, we employed operando X‐ray absorption (XAS) and in situ Raman spectroscopy to elucidate the structure–activity relationships of low‐crystalline cobalt sulfide (L−CoS) catalysts toward overall water splitting. The operando results for L−CoS catalyzing the alkaline hydrogen evolution reaction (HER) demonstrate that the cobalt centers in the bulk are predominantly coordinated by sulfur atoms, which undergo a kinetic structural rearrangement to generate metallic cobalt in S−Co−Co−S moieties as the true catalytically active species. In comparison, during the acidic HER, L−CoS undergoes local structural optimization of Co centers, and H2 production proceeds with adsorption/desorption of key intermediates atop the Co−S−Co configurations. Further operando characterizations highlight the crucial formation of high‐valent Co4+ species in L−CoS for the alkaline oxygen evolution reaction (OER), and the formation of such active species was found to be far more facile than in crystalline Co3O4 and Co‐LDH references. These insights offer a clear picture of the complexity of active species and site formation in different media, and demonstrate how their restructuring influences the catalytic activity. [ABSTRACT FROM AUTHOR]

[Display omitted] The electrochemical performance of pristine metal–organic xerogels as anodes in lithium-ion batteries is reported for the first time. We propose a novel synthesis approach for the in situ generation of highly dispersed, ultrafine cobalt sulfide nanoparticles on humic acid gels (CoSHA). The CoS nanoparticles in CoSHA have an average diameter of approximately 3 nm. CoSHA electrodes demonstrate enhanced lithium storage capacity, delivering a capacity of 662 mAh g−1 at 0.1 A g−1. They also show stable long-term cycling performance, with no capacity decay after 900 cycles at 1.0 A g−1. Furthermore, our experiments indicate that the improved lithium-ion adsorption results from the oxygen-containing functional groups in humic acid and the ultrafine CoS active sites. This study offers a practical methodology for synthesizing ultrafine metal sulfides and new insights into using pristine gel-based electrodes for energy storage and conversion. [ABSTRACT FROM AUTHOR]

In this work, the microwave‐assisted synthesis of ZnxCo1–xS/reduced graphene oxide (rGO) nanocomposite and the evaluation of its electrochemical properties for supercapacitor (SC) application are dealt with. The synergistic effect between ZnxCo1–xS and rGO along with the conducting network provided by rGO facilitates the conducive movement of ions and enhances the electrochemical performance of the nanocomposite. The stoichiometric ratio of Zn:Co:rGO plays a crucial role in the SC behavior of the material. In three electrode systems, a material shows a high specific capacitance of 1094 F g−1 at current density 1 A g−1. The material stores charge both diffusively as well as capacitively. An asymmetric SC with acetylene black as the negative electrode and ZnxCo1–xS/rGO as the positive electrode has a stable potential window 0–1.6 V. For the fabrication of the electrodes, Ni foam is used as the current collector. The energy density and power density of the SC are found to be 32.71 and 431.95 W kg−1, respectively. The Coulombic efficiency of the SC is found to be 107% while its capacitance retention is 86% after 10 000 galvanostatic charge–discharge cycles. The energy and power density of the SC are comparatively higher than many recently reported literature. The material exhibits superior electrochemical stability and reversibility and can be a suitable electrode material for SCs. [ABSTRACT FROM AUTHOR]

In the contemporary age, there is a growing need for innovative energy storage solutions that integrate the crucial features of supercapacitors and rechargeable batteries to meet evolving energy requirements. Herein, we used the hydrothermal method to synthesize a binary composite electrode material. The addition of ZnO as a doping material significantly enhances the specific capacity of cobalt niobium sulphide (CoNbS) from 538.16 C g−1 to 912.62 C g−1 due to its high conductivity and the presence of redox‐active sites. We have also developed a supercapattery (CoNbS@ZnO//activated carbon [AC]), which has demonstrated outstanding performance with a remarkable specific capacity of 325.92 C g−1 at a current density of 1.5 A g−1. Furthermore, the supercapattery device shows improved energy and power densities, measuring 35 Wh/kg and 2397 W/kg, respectively. After 5000 galvanostatic charging discharging (GCD) cycles, the device shows columbic efficiency (90%) and capacity retention (83%). Additionally, the CoNbS@ZnO//AC hybrid device is used as an electrochemical sensor for glucose detection. The device showed a high sensitivity against the glucose and detected up to a small value. The synthesis of nanomaterials opens up new opportunities to create high‐performance energy related systems. [ABSTRACT FROM AUTHOR]

Abstract Regulating the adsorption of an intermediate on an electrocatalyst by manipulating the electron spin state of the transition metal is of great significance for promoting the activation of inert nitrogen molecules (N2) during the electrocatalytic nitrogen reduction reaction (eNRR). However, achieving this remains challenging. Herein, a novel 2D/2D Mott–Schottky heterojunction, Co9S8/Nb2CTx‐P, is developed as an eNRR catalyst. This is achieved through the in situ growth of cobalt sulfide (Co9S8) nanosheets over a Nb2CTx MXene using a solution plasma modification method. Transformation of the Co spin state from low (t2g6eg1) to high (t2g5eg2) is achieved by adjusting the interface electronic structure and sulfur vacancy of Co9S8/Nb2CTx‐P. The adsorption ability of N2 is optimized through high spin Co(II) with more unpaired electrons, significantly accelerating the *N2→*NNH kinetic process. The Co9S8/Nb2CTx‐P exhibits a high NH3 yield of 62.62 µg h−1 mgcat.−1 and a Faradaic efficiency (FE) of 30.33% at −0.40 V versus the reversible hydrogen electrode (RHE) in 0.1 m HCl. Additionally, it achieves an NH3 yield of 41.47 µg h−1 mgcat.−1 and FE of 23.19% at −0.60 V versus RHE in 0.1 m Na2SO4. This work demonstrates a promising strategy for constructing heterojunction electrocatalysts for efficient eNRR.

New heteroleptic dppe appended Co(III)-dithiocarbamate (dtc) complex cations with compositions [Co(S2CNEt2)2(dppe)](PF6) (Co-Et), [Co(S2CNPri2)2(dppe)](PF6) (Co-Pr) and [Co(S2CNBun2)2(dppe)](PF6) (Co-Bu) have been synthesized and characterized by microanalysis, spectroscopic methods and crystallographic analysis. The single crystal X-ray diffraction results indicated that in all three complexes, the coordination environment around Co(III) is distorted octahedral and Co(III) is coordinated to four sulfur centers of the two dtc ligands and the two phosphorus centers of the dppe ligand. These complexes serve as precursors to yield cobalt sulfide/cobalt phosphide nano-composites dCo-Et, dCo-Pr and dCo-Bu by solvothermal decomposition of Co-Et, Co-Pr and Co-Bu, respectively. The decomposed materials have been characterized by PXRD and SEM-EDAX and explored as potential electrocatalysts for both oxygen evolution and hydrogen evolution reactions in basic and acidic media, respectively. Catalytic activity is dependent on the precursor complex and best OER and HER activities are observed for dCo-Bu with an η10 of 230 mV and a Tafel slope of 192.11 mV dec−1 for the OER and an η10 of 470 mV and a Tafel slope of 126.21 mV dec−1 for the HER. [ABSTRACT FROM AUTHOR]

Efforts to create cost-effective electrocatalysts from abundant materials, for the utilization of water electrolysis reactions, are viewed as promising sources for sustainable clean energy generation. This article describes the synthesis of cobalt sulphide (CoS) nanoparticles using a straightforward and environmentally friendly one-pot hydrothermal process. The series of nickel-doped CoS (NiCo 2-x S 4) introduced with varying the weight percentage of Ni (1, 2, 4, 8, 6, and 10 wt%), and the composite Ni-dopped CoS on varying the weight percentage (10, 30, 50, 70, and 90 wt %) of sulfur-doped graphitic carbon nitride (NiCo 2 S 4 @S-g-C 3 N 4) was created. Utilizing X-ray diffraction analysis (XRD), EDS, FTIR, and scanning electron microscopy (SEM) synthesized electrocatalysts were characterized. Doped with Fluorine After being changed with an electrocatalyst, tin oxide was used as the working electrode to monitor the electrochemical activity of the whole water splitting process using chronopotentiometry, cyclic voltammetry (CV), linear sweep voltammetry (LSV), and EIS. NiCo 2 S 4 @S-g-C 3 N 4 exhibited higher electrocatalytic performance with an overpotential 370 mV for OER and 415 mV for HER at the current intensity of 10 mAcm−2. Transition metal sulfide electrocatalysts exhibit good electrolytic performance, due to their high surface areas and intrinsically high catalytic activity. These findings suggest that the NiCo 2 S 4 @S-g-C 3 N 4 composite possesses a significant role for use in energy conversion and energy storage applications. • A series of Ni-doped CoS NPs, and a series of NCS@SGCN were prepared by a one-pot hydrothermal process. • The electrochemical study showed NiCo 2 S 4 @S-g-C 3 N 4 exhibits excellent electrocatalytic activities. • The activity follows the order NiCo 2 S 4 @S-g-C 3 N 4 > NiCo 2 S 4 > CoS. [ABSTRACT FROM AUTHOR]

Enhancing both the number of active sites available and the intrinsic activity of Co‐based electrocatalysts simultaneously is a desirable goal. Herein, a ZIF‐67‐derived hierarchical porous cobalt sulfide decorated by Au nanoparticles (NPs) (denoted as HP‐Au@CoxSy@ZIF‐67) hybrid is synthesized by low‐temperature sulfuration treatment. The well‐defined macroporous–mesoporous–microporous structure is obtained based on the combination of polystyrene spheres, as‐formed CoxSy nanosheets, and ZIF‐67 frameworks. This novel three‐dimensional hierarchical structure significantly enlarges the three‐phase interfaces, accelerating the mass transfer and exposing the active centers for oxygen evolution reaction. The electronic structure of Co is modulated by Au through charge transfer, and a series of experiments, together with theoretical analysis, is performed to ascertain the electronic modulation of Co by Au. Meanwhile, HP‐Au@CoxSy@ZIF‐67 catalysts with different amounts of Au were synthesized, wherein Au and NaBH4 reductant result in an interesting "competition effect" to regulate the relative ratio of Co2+/Co3+, and moderate Au assists the electrochemical performance to reach the highest value. Consequently, the optimized HP‐Au@CoxSy@ZIF‐67 exhibits a low overpotential of 340 mV at 10 mA cm–2 and a Tafel slope of 42 mV dec–1 for OER in 0.1 M aqueous KOH, enabling efficient water splitting and Zn–air battery performance. The work here highlights the pivotal roles of both microstructural and electronic modulation in enhancing electrocatalytic activity and presents a feasible strategy for designing and optimizing advanced electrocatalysts. [ABSTRACT FROM AUTHOR]

Recently, bi-functional electrocatalytic materials have the potential for both the hydrogen evaluation reaction (HER) and oxygen evaluation reaction (OER) in the alkaline medium. In the present investigation, the cobalt sulfide/cobalt oxide hanged on the nitrogen-doped activated carbon nanosheets (CoS/CoO@NAC) as nanocomposites were synthesized through the hydrothermal and then the carbonization processes. The X-ray diffraction peaks observed in the CoS/CoO@NAC nanocomposites revealed the presence of CoS, CoO, and N-doped activated carbon nanosheets which confirmed the formation of binary nanocomposites. The BET analysis of CoS/CoO@NAC nanocomposites resulted an enhancement of the surface area of about 1038.57 m2/g along with the pore size and pore volume of 3.23 nm and 0.442 cc/g, respectively. The CoS/CoO@NAC, nanocomposites were used for bi-functional catalysis which divulged the low over potential for both HER and OER analyses at about −0.266 V and 0.199 V vs. RHE, respectively at 10 mA/cm2 current density in the alkaline medium. [Display omitted] • CoS/CoO@NAC nanocomposites synthesized by hydrothermal and carbonization processes. • CoS/CoO@NAC nanocomposites showed an enhancement of surface area of 1038.57 m2/g. • HER analysis of CoS/CoO@NAC shows an overpotential of −0.266 V. • OER analysis of CoS/CoO@NAC shows an overpotential of 0.2654 V. • CoS/CoO/NAC suitable for the bi-functional electrocatalyst in an alkaline medium. [ABSTRACT FROM AUTHOR]

The designing of efficient electrocatalysts for hydrogen generation is essential for the practical application of water-splitting devices. With numerous electrochemical advantages, transition metal sulphides are regarded as the most promising candidates for catalysing the hydrogen evolution reaction (HER) in acidic media. In the present study, Ru-doped cobalt sulphide nanosheets, termed Co9S8/Ru@t (t = 24 h, 48 h, and 72 h), were obtained by varying the reaction time from 24 h to 72 h from a RuCo-PBA precursor. The role of the time period for the synthesis of Co9S8/Ru@48h is vital in increasing the number of electroactive sites and optimising the hydrogen adsorption–desorption phenomena leading to an increment in the HER activity. The electrochemical outcomes demonstrate that the optimized Co9S8/Ru@48h requires a low overpotential of just 94 mV to produce 10 mA cm−2 current density, and also exhibits a lower Tafel slope value of 84 mV dec−1 defining its faster reaction kinetics. The as-synthesized Co9S8/Ru@48h was stable for up to 20 h of constant electrolysis signifying its outstanding durability. The optimized synthetic approach and impressive electrochemical results make Co9S8/Ru@48h a suitable alternative to noble-metal-based electrocatalysts for the HER. [ABSTRACT FROM AUTHOR]

Dye-sensitized solar cells (DSSCs) have gained recognition as a promising indoor photovoltaic technology, drawing considerable attention for their ability to convert light into electricity. In this study, we present a straightforward one-step hydrothermal synthesis method for producing cobalt sulfide nanoparticles decorated with reduced graphene oxide (CoS2/RGO) nanocomposites, serving as an efficient counter electrode (CE) material for DSSCs. The CoS2/RGO nanocomposites exhibited a chain-like structure formed by RGO nanosheet-decorated spherical particles interconnected with CoS2. Demonstrating excellent electrocatalytic activity with a low Epp (peak-to-peak separation) value, the CoS2/RGO nanocomposites outperformed pristine CoS2 nanoparticles. Moreover, the power conversion efficiency of the CoS2/RGO hybrid structure-based CE surpassed that of the pristine CoS2 nanoparticles. These findings suggest that the facile synthesis of CoS2/RGO nanocomposites holds great promise as an electrode material for effective CEs in DSSC applications. [ABSTRACT FROM AUTHOR]

A CoMoS composite is synthesized to combine the benefits of cobalt and molybdenum sulfides as an anodic material for advanced lithium‐ion batteries (LIBs). The synthesis is accomplished using a simple two‐step hydrothermal method and the resulting CoMoS nanocomposites are subsequently encapsulated in a carbonized polydopamine shell. The synthesis procedure exploited the self‐polymerization ability of dopamine to create nitrogen‐doped carbon‐coated cobalt molybdenum sulfide, denoted as CoMoS@NC. Notably, the de‐lithiation capacity of CoMoS and CoMoS@NC is 420 and 709 mAh g⁻1, respectively, even after 100 lithiation/de‐lithiation cycles at a current density of 200 mA g⁻1. Furthermore, excellent capacity retention ability is observed for CoMoS@NC as it withstood 600 consecutive lithiation/de‐lithiation cycles with 94% capacity retention. Moreover, a LIB full‐cell assembly incorporating the CoMoS@NC anode and an NMC‐532 cathode is subjected to comprehensive electrochemical and practical tests to evaluate the performance of the anode. In addition, the density functional theory showcases the increased lithium adsorption for CoMoS@NC, supporting the experimental findings. Hence, the use of dopamine as a nitrogen‐doped carbon shell enhanced the performance of the CoMoS nanocomposites in experimental and theoretical tests, positioning the material as a strong candidate for LIB anode. [ABSTRACT FROM AUTHOR]

It is imperative to develop an efficient catalyst to reduce the energy barrier of electrochemical water decomposition. In this study, a well-designed electrocatalyst featuring a core–shell structure was synthesized with cobalt sulfides as the core and molybdenum disulfide nanosheets as the shell. The core–shell structure can prevent the agglomeration of MoS2, expose more active sites, and facilitate electrolyte ion diffusion. A CoS2/MoS2 heterostructure is formed between CoS2 and MoS2 through the chemical interaction, and the surface chemistry is adjusted. Due to the morphological merits and the formation of the CoS2/MoS2 heterostructure, CoS2@MoS2 exhibits excellent electrocatalytic performance during the oxygen evolution reaction (OER) process in an alkaline electrolyte. To reach the current density of 10 mA cm−2, only 254 mV of overpotential is required for CoS2@MoS2, which is smaller than that of pristine CoS2 and MoS2. Meanwhile, the small Tafel slope (86.9 mV dec−1) and low charge transfer resistance (47 Ω) imply the fast dynamic mechanism of CoS2@MoS2. As further confirmed by cyclic voltammetry curves for 1000 cycles and the CA test for 10 h, CoS2@MoS2 shows exceptional catalytic stability. This work gives a guideline for constructing the core–shell heterostructure as an efficient catalyst for oxygen evolution reaction. [ABSTRACT FROM AUTHOR]

Metal sulfide stands out as one of the novel and promising platinum‐free counter electrode (CE) materials for dye‐sensitized solar cells (DSSCs). In this work, SnSx‐SnO2‐decorated CoSx films were designed and synthesized by a low‐temperature fabrication process. The small clusters of nanoparticles create a large amount of catalytic active sites, resulting in superior electrocatalytic activity for triiodide reduction. The DSSC with SnSx‐SnO2‐decorated CoSx film has achieved an impressive power conversion efficiency of 4.57 %, which is close to the efficiency of the DSSC with platinum CE (4.82 %). Furthermore, regarding the attenuation of the photovoltaic performance for the DSSC with SnSx‐SnO2‐decorated CoSx film, negligible change was observed after a prolonged storage under ambient condition for five days. Therefore, it is worthwhile to expect the explorations of novel fabricate technique for synthesizing cost‐effective metal sulfide films with long‐term stability in DSSCs. [ABSTRACT FROM AUTHOR]

Owing to the high theoretical energy density, lithium–sulfur batteries (LSBs) stand out from various batteries. However, the slow electrochemical dynamics, the shuttle of lithium polysulfides (LiPSs), and the uncontrolled growth of lithium dendrites seriously affect the cycling performance of LSBs. In this work, we prepared a polypyrrole-coated cobalt sulfide (CoS@PPy) composite through a hydrothermal method followed by in situ polymerization reaction. The internal CoS exhibits strong chemisorption and catalytic conversion ability toward LiPSs. The external PPy can further inhibit the migration of LiPSs through its rich functional groups, thereby improving the electronic conductivity and alleviating the volume expansion of the sulfur electrodes. Therefore, after S loading, the CoS@PPy/S electrode exhibits superior cycling stability, and after 500 cycles at 1 C, its capacity decay is only 0.092% and the satisfactory coulombic efficiency is above 98%. Moreover, the CoS@PPy/S electrode delivers a high reversible capacity of 605 mA h g−1 at 3 C. The present work provides a feasible solution for the synthesis of polymer–metal compound composites and offers a new idea for the construction of efficient sulfur-hosting materials for LSBs. [ABSTRACT FROM AUTHOR]

The fabrication of heterojunctions is an intriguing approach to boost the reactivity of catalysts. However, facile preparation of desirable heterojunction materials remains a challenge. Here, novel CoPS3/CoS2 heterojunctions are created by an intuitive phosphatization process on the basis of structurally flexible cobalt sulfide precursors. Significant stress effect exists at these heterogeneous interfaces, resulting in lattice distortions and the exposure of more active sites. The interface interaction also modifies the catalyst's electronic structure to improve its electrical conductivity and hydrogen adsorption capabilities. Notably, the overpotential of the CoPS3/CoS2 heterojunction for electrocatalytic hydrogen evolution reaction is just 36.3 mV, which is far superior to those of single‐component catalysts and competitive with comparable catalysts reported. This work not only offers an innovative electrocatalyst but also a strategy that can be used to create heterojunctions based on related transition metal thiophosphates. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks, as a kind of advanced nanoporous materials with metal centers and organic linkers, have been applied as promising electrode materials in energy storage devices. In this study, we are successfully prepared cobalt sulfide nanosheets (CoS) derived from the metal–organic framework on nickel foam (NF). The prepared electrodes are characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, energy-dispersive X-ray spectroscopy, Brunauer–Emmett–Teller and Barrett-Joyner-Halenda and electrochemical methods like voltammetry, galvanostatic charge–discharge curve and electrochemical impedance spectroscopy. The CoS/NF electrode demonstrates a high specific capacity of 377.5 mA h g−1 (1359 C g−1) at the current density of 2 A g−1, considerable rate performance and excellent durability (89.4% after 4000 cycles). A hybrid supercapacitor is assembled using CoS/NF as the positive electrode and activated carbon as the negative electrode, it shows a high energy density of 57.4 W h kg−1 at a power density of 405.2 W kg−1. The electrochemical results suggest that the CoS nanosheet arrays would possess excellent potential for applications in energy storage devices. [ABSTRACT FROM AUTHOR]

One potential method to lower the cost of electrocatalytic green hydrogen production is to use metal sulfide-based electrocatalysts in hybrid water electrolysis. This work uses a one-step hydrothermal synthesis to create copper cobalt sulphide (CuCo 2 S 4) nanosheets for hybrid water splitting. Significant water-splitting activity was achieved using urea and organic dye (methylene blue) as supporting electrolytes to avoid delayed OER kinetics. For the KOH + urea and KOH + organic dye electrolytes, the working electrode displays an overpotential of 1.37 V against RHE and 1.30 V vs RHE, respectively, to yield a current density of 10 mA/cm2. The CuCo 2 S 4 working electrode exhibits an overpotential of 212 mV versus RHE and 158 mV vs RHE at 10 mA/cm2 current density while monitoring hydrogen evolution reaction (HER) activity. For the KOH + organic dye electrolyte, the electrode exhibits exceptionally efficient electrocatalytic water splitting, with an overpotential of 1.50 V at a current density of 10 mA/cm2. At high current densities, the CuCo 2 S 4 working electrode shows exceptional stability at industry standards throughout a broad pH range of basic, acidic, neutral, and saline environments. The use of several supporting electrolytes demonstrates an overall water splitting that is energy-efficient. Wastewater treatment can be accomplished through a circular economy strategy by merging the goals of environmental remediation (dye degradation) and renewable energy production (hydrogen evolution). This approach promotes sustainable growth, reduces waste, and encourages resource recovery. According to the internationally endorsed Sustainable Development Goals (SDGs), treating wastewater has the potential to help achieve 11 of the 17 SDGs. • CuCo 2 S 4 is synthesised by hydrothermal technique for bifunctional water splitting. • CuCo 2 S 4 exhibits excellent stability in basic, acidic, neutral, and saline electrolyte. • CuCo 2 S 4 shows the bifunational water electrolysis in alkaline condition. • CuCo 2 S 4 shows advanced oxidation reaction in urea and textile dye electrolyte. [ABSTRACT FROM AUTHOR]

The present study explores the cost-effective and simple co-precipitation technique for the synthesis of bimetallic sulphide, Mn-Co-S@CTAB, nanomaterial, a hybrid of Manganese and Cobalt sulphide along with some surface modification through hexadecyltrimethylammonium bromide (CTAB). Congo red (CR) and Malachite green (MG) dyes were adsorbed out of their solutions onto the surface of produced nanomaterial and whole process has been studied. The adsorption mechanisms for the CR and MG sorption onto the surface of Mn-Co-S@CTAB has been proposed on the basis of investigation of thermodynamics and kinetics of the whole sorption process. To investigate the structural and morphological features of the synthesized nanomaterial, a systematic characterisation were done using FT-IR, P-XRD, SEM-EDX, TGA, TEM, XPS and Zeta Potential measurement were conducted. In order to achieve maximum efficiency, the sorption parameters, including the initial dye concentration, adsorbent dosage, temperature, contact time, and pH of the solutions have been optimized. The Mn-Co-S@CTAB demonstrated strong affinity for CR and MG dyes with sorption capacities of 263.15 and 163.93 mg g-1at 303 K. The positive value of enthalpy, ΔH, indicated the adsorption process to be endothermic for both dyes, while negative free energy change, ΔG, indicated the spontaneous nature of adsorption of these dyes. The Freundlich and Temkin isotherm models provided the closest fit to the data for isotherm investigations for CR and MG sorption onto Mn-Co-S@CTAB, while kinetics of reaction in the examined temperature range followed pseudo-second order kinetics. [Display omitted] • Mn-Co-S@CTAB composite was prepared via facile co-precipitation method. • The composite was utilised for adsorptive removal of Congo red and Malachite green from aqueous solution. • The process of adsorption was found to be spontaneous and endothermic at all studied temperature range. • The rate of adsorption was governed primarily by pseudo second order kinetics. • An efficient and potential material for CR and MG dye treatment technology. [ABSTRACT FROM AUTHOR]

Potassium-ion batteries (PIBs) have gained significant attention as an alternative to lithium-ion batteries (LIBs) due to the abundance of potassium (K) and low cost. Nevertheless, the difficulty in finding appropriate electrode materials that can efficiently store the larger K ions has hindered their practical application. Herein, we report a novel anode material, N-doped multichannel carbon nanofibers embedded with porous CoS nanoprisms (CSP@NMCNF), for high-performance PIBs. The CSP@NMCNF was synthesized using a two-step strategy comprising of the electrospinning of Co acetate hydroxide nanoprism/binary polymer blend and a subsequent heat treatment. The porous CoS nanoprisms with an anisotropic morphology were well aligned along the length axis of the N-doped multichannel carbon nanofibers, thus ensuring their structural stability during the repeated charge–discharge process. In addition, numerous pores facilitated the transport of electrons and ions. Accordingly, the CSP@NMCNF anode exhibited excellent electrochemical performance, delivering a high specific capacity of 368 mAh·g−1 at 0.5 A·g−1 after 200 cycles and excellent rate capability (232 mAh·g−1 at 2.0 A·g−1). [ABSTRACT FROM AUTHOR]

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