Bimetallic Sulfide Research Articles

Understanding the supercapacitive properties and charge storage dynamics of MnCo2S4 bimetallic sulfide electrodes synthesized via a single-step hydrothermal process

A recent study delves into the enhancement of supercapacitors to increase their energy density while maintaining fast charge-discharge capabilities and longevity. This is achieved by developing electrode materials with improved conductivity and carefully designed nanostructures to overcome the limitations of pseudocapacitors. The study highlights MnCo2S4 for its impressive specific capacitance and cost-effectiveness. It elucidates the synergistic interactions and charge transfer dynamics between manganese (Mn) and cobalt (Co), which significantly enhance electrochemical performance. A new one-step hydrothermal synthesis method is presented for producing MnCo2S4 nanogranules directly on a nickel foam substrate, eliminating the need for binders and achieving an optimized morphology that boosts electrochemical activity. Through a thorough analysis involving X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscopy (FE-SEM) along with cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS), the study comprehensively characterizes the structural, morphological, and electrochemical properties of MnCo2S4. The synthesized MnCo2S4 electrode exhibited an outstanding capacitance of 6375 mF/cm2 at a current density of 25 mA/cm2. This exceptional performance is mainly attributed to its well-designed 3-D nanogranular structure, which not only enhances the accessibility of electrolyte ions to active sites, thus improving electrochemical reactivity and capacitive utilization, but also utilizes the synergistic interaction between manganese and cobalt. This synergy promotes enhanced redox reactions and stability, resulting in a higher specific capacitance and energy density. These results highlight the crucial role of advanced electrode material development and creative synthesis methods in advancing supercapacitors as a viable energy storage solution, demonstrating the groundbreaking potential of MnCo2S4 in electrochemical energy storage progress.

Bimetallic phosphidethe nanoparticles as photo-enhanced nanozymes for synergistic cancer immunotherapy

<p class="MsoNormal" style="margin-top: 12pt; text-align: justify;"><span lang="EN-US" style="font-family: 'times new roman', times, serif; font-size: 14pt;">Nanozyme with biomimetic enzyme activity has the advantages of good catalytic performance, high stability, and is not easily affected by temperature. However, the application of tumor microenvironment (TME) in the tumor is limited due to its low catalytic activity. Herein, a multifunctional nanozyme based on CuCoP with multivalent metal ions (Cu+/Cu2+ and Co2+/ Co3+) provides an innovative strategy for constructing acid-responsive cancer therapy. CuCoP has excellent photothermal properties (photothermal conversion efficiency of 66.9%) as well as glutathione (GSH) peroxidase activity and high photo-enhanced peroxidase-like (POD) enzyme activity in weak acid TME. CuCoP can consume the overexpressed GSH, thus alleviating the antioxidant capacity of the tumor, and reduces Cu2+/ Co3+ to Cu+/ Co 2+. Subsequently, the generated Cu+/Co2+ will react with endogenous H2O2 to generate cytotoxic hydroxyl radical (•OH), which have high catalytic efficiency in weakly acidic TME. Crucially, the synergistic effect of PTT and the cascade reaction of bimetallic atoms with GSH and H2O2 can effectively reduce antioxidant capacity, inhibit tumors and trigger effective immune cell death (ICD) process, which caused a strong immune response and inhibit tumor recurrence and metastasis. As a novel bimetallic sulfide nanoenzyme triggered by TME, CuCoP has great research value in cancer therapy.</span></p>

MoS2–CdS composite photocatalyst for enhanced degradation of norfloxacin antibiotic with improved apparent quantum yield and energy consumption

This study introduces an advanced visible light-activated photocatalyst for the efficient degradation of norfloxacin in aqueous environments. CdS nanorods were synthesized on MoS2 through a solution-processable solvothermal method. The resulting MoS2–CdS composite exhibited exceptional photocatalytic oxidative degradation of norfloxacin antibiotic in aquatic media. The optimal degradation efficiency (87.5 %) and degradation rate constant (0.09 min−1) were achieved with the 10 wt% MoS2–CdS composite under light illumination, surpassing pure CdS nanorods by 1.5 and 2.25 times, respectively and the highest apparent quantum yield was obtained for 10 wt% MoS2–CdS composite, which is 1.5 times higher than CdS nanorod, while maintaining consistent experimental conditions. The electrical energy per order for the degradation of norfloxacin in an aqueous solution by 20 mg of CdS in 40 ml aqueous solution is 9.7 kW h m−3/order. This value reduces to 4.8 kW h m−3/order for an equal amount of 10 wt% MoS2–CdS composite. The transfer of photogenerated electrons from the CdS nanorod to MoS2 reduces the recombination probabilities of photogenerated charge carriers and consequently enhancing the photo degradation efficiency of the composite. This research may offer novel insights into the rational design and straightforward synthesis of bimetallic sulfide photocatalysts with commendable performance and cost-effectiveness for the degradation of antibiotics in aqueous environments.

Transition Metals Co, Ni, Mn Based Bimetallic Sulfides as an Efficient Electrocatalyst for Hydrogen Evolution Using Graphite Counter Electrode Extracted from Spent Battery

The clean and green hydrogen energy production by electrochemical process is gaining great attention in recent years. For this, designing an efficient and cost-effective electrocatalyst for the hydrogen evolution reaction (HER) is highly desirable. Herein, Co-Ni-Mn based bimetallic sulfides electrocatalysts are developed for HER in 1 M KOH. Owing to the presence of abundant electrochemical active sites and micro flower-like morphology, the fabricated Co-Ni-S, Ni-Mn-S, Co-Mn-S electrodes deliver the small overpotential of 136, 112, 75 mV to reach the current density of 10 mA cm−2. For practical applications, the commercially available 1.6 V battery is used to drive the overall water splitting process of the device fabricated with the two-electrode system (symmetric device). In addition to this, in this research work, a graphite rod extracted from a spent battery is directly used as a counter electrode for the entire electrochemical study to substitute platinum (Pt) counter electrode. This approach is sustainable as well as eco-friendly.

Simultaneous water sterilization and photodegradation of malachite green based on Z-scheme heterojunction of bimetallic sulfide and zinc phthalocyanine

Multifunctional Z-scheme heterojunction has emerged as an alternative to achieve the photocatalytic sterilization and photodegradation of organic pollutants. Herein, a novel Z-scheme heterojunction based on bimetallic sulfide and zinc phthalocyanine (ZnPc) was established as a robust bifunctional photocatalyst to sterilize and degrade malachite green (MG) contained in wastewater. Ultrathin Ag2S/MoS2 nanosheets were vertically grown over ZnPc nanorods in situ through hydrothermal method, generating a Z-scheme heterojunction (denoted as Ag2S/MoS2@ZnPc). Results showed enhanced photo-adsorption within full spectrum range, narrowed band gap, and modulated electron structure of metal sites of the heterojunction were achieved via the synergistic effect of interface and defect engineering. The Z-scheme Ag2S/MoS2@ZnPc heterojunction demonstrated a boost in the production of reactive oxygen species, superior photothermal effect, high self-supplying H2O2 ability (737.72 μmol g−1h−1), and the controllable release behavior of Ag+ ions under near-infrared (NIR) light irradiation. Almost 100 % bacteria in wastewater were eliminated by this Z-scheme heterojunction owing to the multimodal antibacterial mechanism under NIR illumination (808 nm, 1.0 W cm−2). Moreover, the Ag2S/MoS2@ZnPc heterojunction exhibited high MG absorption capability in the dark (64.95 mg g−1 at 30 min) and enhanced photodegradation ability under ultraviolet–visible light irradiation (96.3 % at 100 min). The practical experiments unveiled that the developed multifunctional photocatalyst could be employed to treat the wastewater containing pathogenic bacteria and organic pollutants via the thorough sterilization and photodegradation/adsorption of MG.

ZnIn2S4 Nanosheets for Efficient NO2 Detection at Room Temperature: Insights into the Role of Sulfur Vacancies.

Engineering atomic vacancies in metal sulfide semiconductors allows for the efficient tuning of their electronic and chemical properties. In this work, we synthesized hollow tubular structures constructed by bimetallic ZnIn2S4 using a metal-organic framework (MOF) as the template. We found that the sulfur vacancies in ZnIn2S4 enabled extremely fast NO2 detection with high response at room temperature (RT), and the material with high sulfur vacancy content delivers a 2 times higher response to 10 ppm NO2 than the device with low sulfur vacancy content. To unveil the crucial role played by sulfur vacancies, DFT calculations were conducted to reveal that sulfur vacancies greatly enhance the interaction and electron transfer between ZnIn2S4 and NO2. This study will provide hints for the engineering of bimetallic sulfide materials for low-power gas sensors at RT.

Binary Co3S4/SnS chalcogenide composites anchored on graphene oxide and carbon nanotubes as anodes for Na-ion batteries

Hetero-architectures are smart for modern energy storage appliances owing to fast charge transportation. However, the smooth and rational assembly with adequate Na+ storage kinetics so far is a significant challenge. Herein, transition-bimetallic sulfides hetero-structured Co3S4/SnS (CTS) and its composites implanted in reduced graphene oxide (CTS.rGO) and carbon nanotubes (CTS.CNTs) have been synthesized and employed as anodes for sodium-ion batteries. The use of highly conductive nature of carbon frames benefits the stability and conductivity of the bimetallic sulfides CTS composites. As a result, the CTS.CNTs delivered a charge capacity 298 mAh/g, whereas CTS.rGO and bare CTS exhibited 229 and 76 mAh/g after 200cycles at 0.05C. In addition, the CTS.CNTs and CTS.rGO displayed excellent rate performance at different rates (0.05C – 10.0C) and upon reversing the C-rate to 0.05C, CTS.CNTs fully restored the charge capacity 329 mAh/g while CTS.rGO restored to 293 mAh/g. The ultra-cyclic stability and improved rate performance enlightening the synergistic effect between CTS and carbon conducting agents. Moreover, the CTS.CNTs displayed the lowest charge transfer resistance (Rct = 604 Ω) as compared to CTS.rGO and bare CTS (Rct = 618 Ω, Rct = 642 Ω), indicating the rapid charge transport.

Nickel-molybdenum bimetallic sulfide decorated biomass derived carbon support for high performance asymmetric supercapacitor application

Biomass - derived carbon electrode material with a porous structure is widely used in supercapacitor applications, which can improve electron transfer and shorter ion diffusion pathways. In this work, the garlic peel biomass carbon (GPBC), NiMo3S4(NMS) and garlic peel biomass carbon decorated with NiMo3S4 (GPBC/NMS) composite were prepared through a in situ two-step hydrothermal method. The synthesized materials were characterized by X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM), energy dispersive x-ray spectroscopy (EDS), Transmission electron microscopy techniques (TEM), Raman spectroscopy and Brunauer-Emmett-Teller (BET) techniques were used to analyze the structure, morphology and specific surface areas and X-ray photoelectron spectroscopy (XPS). The prepared bimetallic metal sulfide on a biomass - derived carbon namely the GPBC/NMS composite is used in supercapacitor application. The GPBC/NMS composite electrode exhibits good cycle performance with high specific capacity of 304C/g at current density of 1 A/g in a 3 M KOH electrolyte solution. The electrochemical performance of the GPBC/NMS//GPBC asymmetric supercapacitor device produces an excellent energy density 45.5 Wh kg−1 at a power density of 1125 W kg−1 in the 1.6 V operating potential window. The GPBC/NMS//GPBC also exhibits 93 % retention of its initial capacitance after the 10,000 GCD cycle performance. The above results demonstrate a new way of developing high performance electrode materials for energy storage applications.

Interface engineering of 2D NiFe LDH/NiFeS heterostructure for highly efficient 5-hydroxymethylfurfural electrooxidation

The electrochemical oxidation of 5-hydroxymethylfurfural (HMF) to valuable chemicals is an efficient way to upgrade biomass molecules and replace traditional catalytic synthesis. It is crucial to develop efficient and low-cost earth-abundant electrocatalysts to enhance catalytic performance of HMF oxidation. Herein, a new type of two-dimensional (2D) hybrid arrays consisting of NiFe layered double hydroxides (LDH) nanosheets and bimetallic sulfide (NiFeS) is constructed via interface engineering for efficient electrocatalytic oxidation of HMF to 2,5-furandicarboxylic acid (FDCA). The preparation process of 2D NiFe LDH/NiFeS with ultrathin heterostructure involves in anchoring a Co-based metal-organic framework (Co MOF) as template onto the carbon cloth (CC) via in-situ growth, formation of NiFe LDH on the surface of Co MOF and subsequent partial sulfidation. The electrocatalyst of NiFe LDH/NiFeS exhibits outstanding performance towards HMF oxidation, about 98.5% yield for FDCA and 97.2% Faraday efficiency (FE) in the alkaline electrolyte with 10 mmol/L HMF, as well as excellent stability retaining 90.1% FE for FDCA after six cycles test. Moreover, even at an HMF concentration of 100 mmol/L, the yield and FE for FDCA remain high at 83.6% and 93.6%, respectively. These findings highlight that 2D heterostructure containing abundant interfaces between NiFe LDH nanosheets and NiFeS can enhance the intrinsic activity of LDH and thus promote the oxidation reaction kinetics. Additionally, the synergistic effect of the bimetallic NiFe compounds also improved the selectivity of HMF conversion to FDCA. Our present work demonstrates that constructing 2D ultrathin heterostructure of NiFe LDH/NiFeS is a facile strategy via interface engineering to enhance the intrinsic activity of LDH electrocatalysts, which would open new avenues toward low-cost and advanced 2D nanocatalysts for sustainable energy conversion and electrochemical valorization of biomass derivatives.

Pulsed Electro Decoration of Carbon Nanotubes with FexZn1−xS

Pulsed Electro Decoration of Carbon Nanotubes with FexZn1−xS

Acanthosphere-like bimetallic sulfide Cu9S5/Mo2S3/NF as bifunctional catalyst for water splitting

Reducing the overpotential of water splitting is an important strategy for achieving low-cost and large-scale production of hydrogen (H2) and oxygen (O2). It is shown that bimetallic sulfide combines the advantages of a single component and an ideal structure for efficient electrocatalysis. Hence, an acanthosphere-like bimetallic sulfide electrocatalyst Cu9S5/Mo2S3/NF with high catalytic performance and superior durability was prepared by a simple one-pot method. In the oxygen evolution reaction (OER), the Cu9S5/Mo2S3/NF achieved a Tafel slope of 62.7 mV dec-1, and an overpotential of 224 mV at a current density of 10 mA cm−2. Concomitantly, it also possesses a small overpotential of 96 mV at 10 mA cm−2 and low Tafel slope of 81.6 mV dec-1 at the used of hydrogen evolution reaction (HER) catalyst. Moreover, the two-electrode system Cu9S5/Mo2S3/NF||Cu9S5/Mo2S3/NF single cell requires only 1.55 V to achieve a current density of 10 mA cm−2 in overall water splitting. This work highlights the advantages of bimetallic sulfide combines structural for overpotential of water splitting and provides an idea for modifying the catalytic performance of single metal sulfides and preparing high-performance bimetallic sulfide catalysts.

One-Pot Synthesis of Nanoflower-Like Zn2SnS4 as Nanozymes for Highly Sensitive Electrochemical Detection of H2O2 Released by Living Cells.

The sensitive and reliable nanozyme-based sensor enables the detection of low concentrations of H2O2 in biological microenvironments, it has potential applications as an in-situ monitoring platform for cellular H2O2 release. The uniformly dispersed bimetallic sulfide (Zn2SnS4) nanoflowers were synthesized via a one-pot hydrothermal method and the two kinds of metal ions can serve as morphology and structure directing agents for each other in the synthetic process. The nanoparticles were utilized as nanozyme materials to fabricate a novel electrochemical sensor, and it exhibits a distinct electrochemical response towards H2O2 with excellent stability and detection capability (with a minimum detection limit of 1.79 nM (S/N=3)), the excellent characteristics facilitate the precise detection of low concentrations of H2O2 in biological microenvironments. Use the macrophages differentiated from leukemia THP-1 cells as a representative sensing model, the sensor was successfully utilized for real-time monitoring of the release of H2O2 induced by living cells, which has significant potential applications in clinical diagnosis and cancer treatment.

Metal Doping Regulates Electrocatalysts Restructuring During Oxygen Evolution Reaction.

High-efficiency and low-cost catalysts for oxygen evolution reaction (OER) are critical for electrochemical water splitting to generate hydrogen, which is a clean fuel for sustainable energy conversion and storage. Among the emerging OER catalysts, transition metal dichalcogenides have exhibited superior activity compared to commercial standards such as RuO2, but inferior stability due to uncontrolled restructuring with OER. In this study, we create bimetallic sulfide catalysts by adapting the atomic ratio of Ni and Co in CoxNi1-xSy electrocatalysts to investigate the intricate restructuring processes. Surface-sensitive X-ray photoelectron spectroscopy and bulk-sensitive X-ray absorption spectroscopy confirmed the favorable restructuring of transition metal sulfide material following OER processes. Our results indicate that a small amount of Ni substitution can reshape the Co local electronic structure, which regulates the restructuring process to optimize the balance between OER activity and stability. This work represents a significant advancement in the development of efficient and noble metal-free OER electrocatalysts through a doping-regulated restructuring approach.

Significantly enhanced ion‐migration and sodium‐storage capability derived by strongly coupled dual interfacial engineering in heterogeneous bimetallic sulfides with densified carbon matrix

AbstractThe development of highly efficient sodium‐ion batteries depends critically on the successful exploitation of advanced anode hosts that is capable of overcoming sluggish reaction kinetics while also withstanding severe structural deformation triggered by the large radius of Na+‐insertion. Herein, a hierarchically hybrid material with hetero‐Co3S4/NiS hollow nanosphere packaged into a densified N‐doped carbon matrix (Co3S4/NiS@N‐C) was designed and fabricated utilizing CoNi‐glycerate as the self‐sacrifice template, making the utmost of the synergistic effect of hetero‐Co3S4/NiS with strong electric field and rich reaction active‐sites together with the densified outer‐carbon scaffolds with remarkable electronic conductivity and robust mechanical toughness. As anticipated, as‐fabricated Co3S4/NiS@N‐C anode affords remarkable specific capacity, prolonged cycle lifespan up to 2 400 cycles with an only 0.05% fading each cycle at 20.0 A g−1, and excellent rate feature (354.9 mAh g−1 at 30.0 A g−1), one of the best performances for most existing Co3S4/NiS‐based anodes. Ex situ structural characterizations in tandem with theoretical analysis demonstrate the reversible insertion‐conversion mechanism of initially proceeding with Na+ de‐/intercalation and superior heterogeneous interfacial reaction behavior with strong Na+‐adsorption ability. Further, sodium‐ion full cell and hybrid capacitor based on Co3S4/NiS@N‐C anode exhibit impressive electrochemical characteristics on cycling performance and rate capability, showcasing its outstanding feasibility toward practical use.

Exploring the Synergistic Potential of Bimetallic Sulfide (SrCuS) as Battery‐Grade Electrode Material for Hybrid Supercapacitor Applications

State‐of‐the art hybrid energy storage devices, owing to their attractive electrochemical features of high specific energy, power, and great stability, have earned incredible attention throughout the world. Herein, bimetallic sulfide (SrCuS) composites with different concentration are electrochemically analyzed for hybrid supercapacitor applications. In half‐cell assembly, amidst all compositions, Sr0.5Cu0.5S reveals relatively better performance demonstrating specific capacity “Qs” of 596.48 C g−1. To assess the hybrid device's (Sr0.5Cu0.5S//AC) electrochemical performance, positive electrode (Sr0.5Cu0.5S) along with activated carbon as negative electrode is utilized. The device displayed energy density “Ed” of (51.28 W h kg−1) and power density “‘Pd” of 6800 W kg−1. Furthermore, the device is examined for capacitive‐ and diffusive‐controlled processes employing a semi‐empirical approach, using linear and quadratic models, respectively.

Synergy of Cu doping and SO42− adsorption in the self-optimized SO42−@Cu doped Co(OH)2 reconstructed from CuCo2S4 towards enhanced oxygen evolution reaction

Catalysts in-situ reconstructed from transition metal sulfides for oxygen evolution reaction (OER) have been regarded as potential alternatives for the noble metal catalysts. Intriguingly, it was found that the self-optimized SO42−@Cu doped Co(OH)2 catalyst was reconstructed from bimetallic sulfide of CuCo2S4. During the OER process, the copper was partially leached and meantime doped into the in-situ generated Co(OH)2 with SO42− adsorption, while only oxides were discovered in counterparts of mono-metal sulfides. As a result, the SO42−@Cu doped Co(OH)2 catalyst exhibited superior OER performances, with low overpotentials of 211/272 mV to achieve the current densities of 10/100 mA cm−2, exceeding the counterparts reconstructed from mono-metal sulfides. Experimental and theoretical results suggested that the in situ generated Cu doped Co(OH)2 possessed thin and loosely layered structure with expanded lattice spacing (lattice spacing expanded from 0.28 nm to 0.46 nm) due to the SO42− adsorption, making the intermediates more accessible to the active centers. In addition, the catalyst surface changed from hydrophobicity to super hydrophilicity, which greatly accelerated the mass transfer. This work indicated that the in-situ reconstruction process was greatly influenced by the interactions between metal sites and sulfide species, directly influencing the OER performances of the reconstructed catalysts.

MoS2/ReS2 Hollow Heterojunction for Enhanced Aqueous Zinc-Ion Storage Performance.

The research of cathode materials for water-based zinc ion batteries (ZIBs) is very hot because the current mainstream electrode makes it difficult to meet the requirements of high specific discharge capacity and maintain a stable structure in the electrochemical process. In this work, the cathode properties are adjusted by the modification idea of morphology regulation and heterojunction construction. The simple hydrothermal method is used to prepare the hollow bimetallic heterojunction nanospheres, and their electrochemical properties as cathode materials for ZIBs are studied for the first time. Herein, the optimized cathode delivers high-rate performance and long-term cycling stability (∼98.9% Coulombic efficiency at 0.1 A g-1 after 200 cycles). The results indicate that the hollow bimetallic heterojunction nanospheres can support the material structure and provide a wide Zn2+ migration channel. The excellent performance is because hollow heterojunction bimetallic sulfides can provide abundant catalytic active sites, improve the mobility of electrons, and enhance the battery performance fundamentally. Therefore, we firmly believe that the combination of the different modification ideas can coordinate to adjust the electrode performance of ZIBs, enriching the electrode types and expanding the energy system application range.

Interfacial modulation of hollow ZnS-SnS2 microboxs by Ti3C2Tx MXene to construct three-dimensional hybrid anodes for lithium-ion batteries with ultra high stability at low temperature

Metal sulfides exhibit obvious volume expansion due to the inherent poor conductivity and large temperature fluctuations, leading to reduced storage capacity. Herein, an electrostatic self-assembly strategy was proposed to fabricate a three-dimensional (3D) polyaniline (PANI) encapsulated hollow ZnS-SnS2 (H-ZSS) heterojunction confined on Ti3C2Tx MXene nanosheets (H-ZnS-SnS2@MXene@PANI, denoted as H-ZSSMP), which exhibits remarkable reversible capacity and cyclic stability (520.3 mAh/g at 2 A/g after 1000 cycles) at room temperature. Additionally, specific capacity can stabilized at 362.5 mAh/g for 250 cycles at −20 °C. A full cell with the configuration of H-ZSSMP//lithium iron phosphate (LiFePO4) can retain a satisfactory reversible capacity of 424.7 mAh/g after 100 cycles at 0.1 C. Theory calculations confirm heterogeneous interface can accelerate the transfer of ions through the interfacial regulation effect of MXene on H-ZSS. Our work provides a simple strategy to improve the capacity and stability of lithium-ion batteries (LIBs), as well as the new applications of MXene and bimetallic sulfides as anode materials, which will facilitate the development of MXene based composites for energy storage.

Sulfur vacancies and heterogeneous interfaces promote high performance sodium storage of bimetallic chalcogenide hollow nanospheres

Transition metal sulfides have high theoretical capacities and are considered as potential anode materials for sodium-ion batteries. However, due to low inherent conductivity and significant volume expansion, the electrochemical performance is greatly limited. In this study, a nickel/manganese sulfide material (Ni0.96Sx/MnSy-NC) with adjustable sulfur vacancies and heterogeneous hollow spheres was prepared using a simple method. The introduction of a concentration-adjustable sulfur vacancy enables the generation of a heterogeneous interface between bimetallic sulfide and sulfur vacancies. This interface collectively creates an internal electric field, improving the mobility of electrons and ions, increasing the number of electrochemically active sites, and further optimizing the performance of Na+ storage. The direction of electron flow is confirmed by Density functional theory (DFT) calculations. The hollow nano-spherical material provides a buffer for expansion, facilitating rapid transfer kinetics. Our innovative discovery involves the interaction between the ether-based electrolyte and copper foil, leading to the formation of Cu9S5, which grafts the active material and copper current collector, reinforcing mechanical supporting. This results in a new heterostructure of Cu9S5 with Ni0.96Sx/MnSy, contributing to the stabilization of structural integrity for long-cycle performance. Therefore, Ni0.96Sx/MnSy-NC exhibits excellent electrochemical properties following our modification route. Regarding stability performance, Ni0.96Sx/MnSy-NC demonstrates an average decay rate of 0.00944% after 10,000 cycles at an extremely high current density of 10000 mA g−1. A full cell with a high capacity of 304.2 mA h g−1 was also successfully assembled by using Na3V2(PO4)3/C as the cathode. This study explores a novel strategy for interface/vacancy co-modification in the fabrication of high-performance sodium-ion batteries electrode.

Controllable synthesis of a hybrid mesoporous sheets-like Fe0.5NiS2@ P, N-doped carbon electrocatalyst for alkaline oxygen evolution reaction

Owing to the high cost of precious metal catalysts for the oxygen evolution reaction (OER), the production of highly efficient and affordable electrocatalysts is important for generating pollution-free and renewable energy via electrochemical processes. A facile hydrothermal approach was employed to synthesize hybrid mesoporous iron-nickel bimetallic sulfides @ P, N-doped carbon for the OER. The prepared Fe0.5NiS2@C exhibited an overpotential (η) of 250 mV at 10 mA/cm2. This exceeded the overpotentials recently reported for surface-modified P, N-doped carbon-based catalysts for the OER in a 1 M KOH medium. Moreover, the Fe0.5NiS2@C catalyst showed a notable Tafel slope of 90.5 mV/dec with long-dated stability even after 24 h at 10 mA/cm2. The superior OER performance of the Fe0.5NiS2@C catalysts may be due to their large surface area, sheet-like morphology with abundant active sites, fast transfer of mass and electrons, control of the electronic structure by co-treatment with heteroatoms (e.g., P and N), and the synergistic effect of bimetallic sulfides, making them favorable catalysts for the oxygen evolution reaction. Density functional theory (DFT) calculations showed that the Fe0.5NiS2@C catalyst exhibited strong H2O-adsorption energy. The enhanced OER activity of Fe0.5NiS2@C was attributed to its higher surface area, favorable H2O adsorption energy, improved electron transfer efficiency, and lower Gibbs free energy compared to those of the other proposed catalysts.