Sulfide Heterostructures Research Articles

S−S Bond Strategy at Sulfide Heterointerface: Reversing Charge Transfer and Constructing Hydrogen Spillover for Boosted Hydrogen Evolution

AbstractDeveloping efficient electrocatalyst in sulfides for hydrogen evolution reaction (HER) still poses challenges due to the lack of understanding the role of sulfide heterointerface. Here, we report a sulfide heterostructure RuSx/NbS2, which is composed of 3R‐type NbS2 loaded by amorphous RuSx nanoparticles with S−S bonds formed at the interface. As HER electrocatalyst, the RuSx/NbS2 shows remarkable low overpotential of 38 mV to drive a current density of 10 mA cm−2 in acid, and also low Tafel slope of 51.05 mV dec−1. The intrinsic activity of RuSx/NbS2 is much higher than that of Ru/NbS2 reference as well as the commercial Pt/C. Both experiments and theoretical calculations unveil a reversed charge transfer at the interface from NbS2 to RuSx that driven by the formation of S−S bonds, resulting in electron‐rich Ru configuration for strong hydrogen adsorption. Meanwhile, electronic redistribution induced by the sulfide heterostructure facilitates hydrogen spillover (HSo) effect in this system, leading to accelerated hydrogen desorption at the basal plane of NbS2. This study provides an effective S−S bond strategy in sulfide heterostructure to synergistically modulate the charge transfer and adsorption thermodynamics, which is very valuable for the development of efficient electrocatalysts in practical applications.

Unlocking hierarchical hollow nanoblocks of NiMo sulfide with extended interlayer spacing of Mo-S units for high-performance supercapacitor

Molybdenum sulfide (MoS2) has been investigated as electrode of supercapacitor due to its unique structure. However, the restricted availability of active sites and sluggish behavior at the basal surface impede its improvement. Here we propose an unlocking hierarchical hollow strategy to synthesis the bimetallic sulfide heterostructures loaded on the ultrathin carbon (NiS/MoS2@UC). The unlocking hierarchical hollow structure and extended S-Mo layer provide interconnected channels for rapid electrolyte ion transport, while the heterojunction interface promotes the electron transfer and redox reaction. As a result, NiS/MoS2@UC − 2 exhibits a high specific capacitance of 616.7F g−1 at the current density of 1 A/g, which is approximately 10 times higher than that of MoS2@UC and 6 times higher than that of NiS@UC. Moreover, NiS/MoS2@UC − 2 demonstrates a high energy density of 7.7 Wh kg−1 at the power density of 300 W kg−1 with excellent cycling durability.

Well-dispersed NiFeS2@Cu2S heterojunction nanorods as high energy density electrode for supercapacitors

Transition metal sulfide heterostructures have demonstrated significant potential in enhancing the performance and cycling stability of supercapacitors due to their adjustable electronic structure. In this study, we synthesized an integrated electrode by constructing NiFeS2@Cu2S heterostructure nanorods onto a copper foam (CF) substrate. The heterostructure displays a crucial role in improving the electrochemical properties of the NiFeS2@Cu2S electrode, which exhibits a high specific capacity of 588 mAh g−1 at a current density of 1 A g−1. Moreover, The assembled CF@NiFeS2@Cu2S //CF@AC asymmetric supercapacitor (ASC) delivers an impressive energy density of 68.6 Wh kg−1 at a power density of 800 W kg−1. This work provides a novel strategy to design and construct highly efficient electrode materials for energy storage applications.

S-S Bond Strategy at Sulfide Heterointerface: Reversing Charge Transfer and Constructing Hydrogen Spillover for Boosted Hydrogen Evolution.

Developing efficient electrocatalyst in sulfides for hydrogen evolution reaction (HER) still poses challenges due to the lack of understanding the role of sulfide heterointerface. Here, we report a sulfide heterostructure RuSx/NbS2, which is composed of 3R-type NbS2 loaded by amorphous RuSx nanoparticles with S-S bonds formed at the interface. As HER electrocatalyst, the RuSx/NbS2 shows remarkable low overpotential of 38 mV to drive a current density of 10 mA cm-2 in acid, and also low Tafel slope of 51.05 mV dec-1. The intrinsic activity of RuSx/NbS2 is much higher than that of Ru/NbS2 reference as well as the commercial Pt/C. Both experiments and theoretical calculations unveil a reversed charge transfer at the interface from NbS2 to RuSx that driven by the formation of S-S bonds, resulting in electron-rich Ru configuration for strong hydrogen adsorption. Meanwhile, electronic redistribution induced by the sulfide heterostructure facilitates hydrogen spillover (HSo) effect in this system, leading to accelerated hydrogen desorption at the basal plane of NbS2. This study provides an effective S-S bond strategy in sulfide heterostructure to synergistically modulate the charge transfer and adsorption thermodynamics, which is very valuable for the development of efficient electrocatalysts in practical applications.

Constructing novel Sn-Mo bimetallic sulfide heterostructures for enhanced catalytic performance towards the hydrogen evolution reaction

Understanding the design principles of efficient electrocatalysts using the structure–activity relationship is crucial for the advancement of energy-related applications, and specifically the hydrogen evolution reaction (HER). Non-precious electrocatalysts with low overpotentials are essential for driving the HER and achieving high energy efficiency. In this study, we synthesized and thoroughly investigated various heterostructures combining Mo and Sn sulfides, ranging from complete phase-separated hybrids to homogeneous mixtures: SnS@MoS2 core–shell structures, SnS/MoS2 with edge-rich Mo and (SnxMo1-x)S with uniformly distributed Sn-Mo. Our findings reveal that the SnS@MoS2 structure exhibited relatively high intrinsic activity characterized by a high electrochemical active surface area and rapid charge transfer kinetics, thereby enhancing the HER catalytic performance. The presence of fluffy MoS2 layers provided an abundance of optimized sites for HER, potentially due to strain and defects such as S vacancies, known as active catalytic sites. The optimal structure facilitated efficient charge transfer from the core to the shell, improving conductivity and catalytic activity. Our research highlights the advantages of a core–shell hybrid structure, offering guiding principles for the development of an optimal SnS@MoS2 catalyst.

Self-supported bimetallic iron-nickel sulfide nanosheets for efficient alkaline electrocatalytic oxygen evolution

The ongoing pursuit of cost-effective approaches for synthesizing transition metal sulfide heterostructure oxygen evolution electrocatalysts, with the objective of optimizing active site exposure and stabilizing spatial framework, remains a significant challenge. In this study, self-supported bimetallic iron-nickel sulfide (Fe1-xS-NiS/NF) nanosheet heterostructures were successfully fabricated in situ on nickel foam through the direct sulfurization of bimetallic carbonate precursors. The effects of sulfurization temperature and Fe content on the oxygen evolution reaction (OER) performance of the catalyst are investigated, and the best conditions are found to be 350 °C and 2 mmol, respectively. As expected, the optimized catalyst demonstrates remarkable OER performance in an alkaline solution with low overpotentials of 235 mV and 333 mV at high current densities of 50 mA cm−2 and 100 mA cm−2, respectively. Furthermore, the catalyst shows long-term stability lasting for 35 h at 60 mA cm−2 with a negligible shift in the polarization curve observed even after 2000 cyclic voltammetry cycles, while also exhibiting good structural preservation. The current study has the potential to offer valuable insights into the fabrication of electrocatalysts based on metal sulfide heterostructures.

Hierarchical nanowires of MoS2@transition metal sulfide heterostructures for efficient electrocatalytic hydrogen evolution reaction

Transition metal sulfides have attracted much attraction in electrochemical water splitting owing to their low cost and unlimited availability. The formation of heterostructures has been demonstrated to be an effective manner to enhance the electrocatalytic performance. In this paper, hierarchical nanowires of MoS2@transition metal sulfide (FeS, CuS, CoS2 and SnS2) heterostructures were fabricated via simple electrospinning, sulfuration and subsequent hydrothermal process. X-ray diffraction and X-ray photoelectron spectroscopy were utilized to character the crystal structures and chemical compositions of as-prepared electrocatalysts. Scanning electron microscope and transmission electron microscope characterization results confirmed the existence of heterostructures in the MoS2@transition metal sulfide hybrid nanowires. Benefitting from the synergistic effect and the increased active sites, the as-prepared MoS2@transition metal sulfide (FeS, CuS, CoS2 and SnS2) heterostructures exhibited superior electrocatalytic HER performance. The MoS2@transition metal sulfides (FeS, CuS, CoS2 and SnS2) delivered the overpotential of 52 mV, 62 mV, 88 mV and 93 mV at the current density of 10 mA/cm2, and the Tafel slope of 64 mV/dec, 82 mV/dec, 73 mV/dec and 70 mV/dec in acid media. This work provides a novel way to optimize the HER activity of nanostructured MoS2.

Fabrication of nickel-cobalt sulfide heterostructures with stable thermodynamic interfaces and enhanced electrochemical performance

Transition metal sulfides (TMS) with multicomponent heterostructure have been widely used as electrodes in electrochemical energy storage devices due to their abundant electroactive sites and fast charge transfer across the interfaces. Different kinds of heterostructures with specific TMS are fabricated by various routes to date, but it is still poorly understood how specific thermodynamic interfaces can be designed and easily coupled. Herein, the spinel and cobalt-pentlandite crystal phases of nickel–cobalt sulfides were chosen as models to demonstrate the formation of epitaxial heterointerface. The density functional theory calculations revealed the easy combination and high compatibility of these two crystal phases at the (111) plane. Along this guideline, a novel NiCo2S4/[Ni, Co]9S8 heterostructure was synthesized by a facile one-step hydrothermal strategy, with nanosheet-like shapes and well-defined heterointerfaces along the [111] crystal direction. The formation mechanism of the epitaxial heterointerface was proposed through the combination of solid and liquid phase reaction fields. As a proof-of-concept application, the obtained NiCo2S4/[Ni, Co]9S8 heterostructure as redox electrode for supercapacitor exhibits an enhanced specific capacitance of 1780F g−1 at 1 A/g and high capacitance retention of 70 % at 20 A/g. Moreover, the assembled aqueous hybrid supercapacitor of NiCo2S4/[Ni, Co]9S8//activated carbon delivers a high energy density of 62.8 Wh kg−1 at 0.4 kW kg−1 and excellent electrochemical stability after 3000 cycles. This work provides a new perspective on the epitaxial design of nickel–cobalt sulfide heterostructure with good lattice match as a promising electrode in energy storage devices.

Zinc oxide‐cadmium(II) sulfide heterostructure as a potential photocatalyst for preparing substituted chromenes and its anti‐liver cancer activity

There are ongoing studies on the potential use of chromene derivatives in liver cancer therapy. They have shown promising results in preclinical studies for liver cancer, including inhibiting tumor growth and inducing apoptosis. Herein, the nanosized hybrid material zinc oxide (ZnO)–cadmium sulfide (CdS) is prepared using a green and ecofriendly procedure. The nanomaterial was characterized by FE‐SEM, transmission electron microscopy, energy dispersive X‐ray, DRS, X‐ray diffraction, and Fourier transform infrared spectroscopy. The photocatalytic proficiency of ZnO–CdS was then scrutinized in the fabrication of some 4H‐chromenes in a mild condition. The outcomes of this study revealed that the nanophotocatalyst has high photocatalytic reactivity and acceptable reusability in the desired condensation reaction. Furthermore, a preliminary in vitro cellular toxicity assay was performed on ZnO–CdS nanoparticles using HepG2 cancer cell line through MTT assay.

Design of heterostructured hydrangea-like FeS2/MoS2 encapsulated in nitrogen-doped carbon as high-performance anode for potassium-ion capacitors

The means of structural hybridization such as heterojunction construction and carbon-coating engineering for facilitating charge transfer and electron transport are considered viable strategies to address the challenges associated with the low rate capability and poor cycling stability of sulfide-based anodes in potassium-ion batteries (PIBs). Motivated by these concepts, we have successfully prepared a hydrangea-like bimetallic sulfide heterostructure encapsulated in nitrogen-doped carbon (FMS@NC) using a simple solvothermal method, followed by poly-dopamine wrapping and a one-step sulfidation/carbonization process. When served as an anode for PIBs, this FMS@NC demonstrates a high specific capacity (585 mAh g−1 at 0.05 A/g) and long cycling stability. Synergetic effects of mitigated volume expansions and enhanced conductivity that are responsbile for such high performance have been verified to originate from the heterostructured sulfides and the N-doped carbon matrix. Meanwhile, comprehensive characterization reveals existence of an intercalation-conversion hybrid K-ion storage mechanism in this material. Impressively, a K-ion capacitor with the FMS@NC anode and a commercial activated carbon cathode exhibits a superior energy density of up to 192 Wh kg−1, a high power density, and outstanding cycling stability. This study provides constructive guidance for designing high-performance and durable potassium-ion storage anodes for next-generation energy storage devices.

Synthesis of MoS2@NdS heterostructures featuring augmented field emission performance

A molybdenum disulfide and neodymium sulfide (MoS2–NdS) heterostructure was successfully fabricated through a facile three-step synthesis process using the spin coating technique exhibiting remarkable field emission properties.

In situ constructed bimetallic sulfide heterostructures on 3D graphene for efficient lithium storage

The ultra-fine multicomponent heterogeneous SnS/CoS@rGO materials have rapid transfer kinetics and structural stability, exhibiting excellent rates and cycling performances.

Evaluation of zinc sulfide heterostructures as catalysts for the transformation of CO2 into valuable chemicals and clean energy generation

Zinc sulfide (ZnS) and doped ZnS have gained significant attention for the potential catalytic transformation of CO2 into useful compounds.

Integrated design and construction of the NiMoS4@Co9S8/Ni3S2 hollow core–shell heterostructure for high-performance asymmetric supercapacitors

A multi-component NiMoS4@Co9S8/Ni3S2 heterostructure with hollow core–shell morphology exhibits excellent electrochemical performances for asymmetric supercapacitor.

Promoting the four electrocatalytic reactions of OER/ORR/HER/MOR using a multi-component metal sulfide heterostructure for zinc-air batteries and water-splitting.

Multi-component metal sulfide heterostructures are promising for multi-functional catalytic activities. In this work, we fabricated a multi-component metal sulfide heterostructure (Co-S-INF, composed of Co3S4 and (Fe, Ni)9S8) with nanoflower morphology clustered with numerous nanosheets by the electrodeposition of cobalt on iron-nickel foam followed by hydrothermal sulfurization treatment. Co-S-INF possesses high multi-functional electrocatalytic properties toward the oxygen evolution reaction (OER), oxygen reduction reaction (ORR), hydrogen evolution reaction (HER), and methanol oxidation reaction (MOR). In particular, the ORR potential at 10 mA cm-2 is 0.682 V, and the OER, HER, and MOR potentials at 100 mA cm-2 are 1.478 V, 0.289 V, and 1.417 V, respectively. By using Co-S-INF, the aqueous ZAB with an ultrahigh peak power density of 332.30 mW cm-2 and an overall water splitting (OWS) device with a low splitting voltage of 1.82 V at 100 mA cm-2 can be obtained. In addition, the OWS potential can be further decreased to 1.70 V at a current density of 100 mA cm-2 with the assistance of MOR at the anode accompanying the production of the high value-added formate. Our work opens the way for the application and development of multi-functional electrocatalysts.

Self-supporting trimetallic NiCoFe layered-double-hydroxide/amorphous sulfide heterostructure on nickel foam for efficient water splitting

For efficient overall water splitting, a ternary layered double hydroxide (LDH) and sulfide (NiCoFeLDH/NiCoFeS) composite on nickel foam (NF) has been developed as a bifunctional catalytic electrode. The growth of NiCoFeLDH/NiCoFeS–NF catalysts take place employing a three-step process that involves hydrothermal-sulfurization-hydrothermal reaction. Ultrafine nano-needle NiCo(OH)2 is deposited on the NF using a hydrothermal process, followed by immersion in Na2S solution, which ensures its mild conversion to NiCo sulfide. The Fe ions incorporated during the secondary hydrothermal process participate in the dissolution-recrystallization process of the lattice and modify the electronic structure, thereby significantly enhancing endogenous activity. The hetero-structured interface between NiCoFeLDH and NiCoFeS provides additional catalytic reaction sites, improves electronic interactions, and facilitates water dissociation kinetics. NiCoFeLDH/NiCoFeS–NF demonstates improved performance in both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). The HER and OER overpotentials are measured to be only 191 and 241 mV at a current density of 100 mA cm−2 in 1 M KOH solution, respectively. Therefore, when NiCoFeLDH/NiCoFeS–NF has been employed as bifunctional electrodes for water splitting, 50 mA cm−2 is reached at only 1.63 V.

Recycling the Spent LiNi1- x - yMnxCoyO2 Cathodes for High-Performance Electrocatalysts toward Both the Oxygen Catalytic and Methanol Oxidation Reactions.

The traditional recycling methods of the spent lithium ion batteries (LIBs) involve the intricate and cumbersome steps. This work proposes a facile method of acid leaching followed by the sulfurization treatment to achieve the high Li leaching efficiency, and obtain high-performance multi-function electrocatalysts for oxygen reduction (ORR), oxygen evolution (OER), and methanol oxidation reactions (MOR) from the spent LIB ternary cathodes. By this method, the Li leaching efficiency from the spent LIB ternary cathode can reach 98.3%, and the transition metal sulfide heterostructures (LNMCO-H-450S) consisting MnS, NiS2, and NiCo2S4 phases can be obtained. LNMCO-H-450S shows the superior bifunctional oxygen catalytic activities with ORR half-wave potential of 0.763V and OER potential at 10mA cm-2 of 1.561V, surpassing most of the state-of-the-art electrocatalysts. LNMCO-H-450S also demonstrates the superior MOR catalytic activity with the potential at 100mA cm-2 being 1.37V. Using LNMCO-H-450S as the oxygen catalyst, this work can construct the aqueous and solid-state zinc-air batteries with high power density of 309 and 257mW cm-2, respectively. This work provides a promising strategy for the efficient recovery of Li, and reutilization of Ni, Co, and Mn from the spent LIB ternary cathodes.

One-step electrodeposition of NiS heterostructures on nickel foam electrodes for hydrogen evolution reaction: on the impact of thiourea content

Herein, we report on the one-step growth of nickel sulfide (NiS) heterostructures on nickel foam (NF) substrate via a facile electrodeposition method, employing Ni(NO3)2.6H2O and CH4N2S as Ni and S precursors, respectively. For the first time, a systematic study was carried out on the impact of the Ni/S molar ratio on the electrochemical performance of as-prepared electrodes for water splitting. The optimum performance was obtained for a Ni:S ratio equal to 2:1, whereas lower or higher ratios resulted in much inferior performance. The NiS@NF electrode with a Ni:S ratio of 2:1 exhibited the lowest overpotentials |η10| = 136 mV, |η100| = 209 mV, extremely low Tafel slope (60 mV dec-1), and very high double layer capacitance value (2.78 mF cm-2). Field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), and X-ray photoelectron spectroscopy (XPS) revealed the formation of coral-like nanoarchitecture, resulting in enhanced HER activity.

Synergistic two-dimensional metal sulfide heterostructures from ZIF-67: A promising catalyst for efficient overall water splitting

The morphology of nanomaterials plays a significant role in electrocatalytic water splitting. Metal–organic frameworks (MOFs) offer several advantages, including high porosity, large specific surface area, adjustable structure and various morphologies. Among the various MOFs, zeolitic imidazolate framework-67 (ZIF-67) is a cobalt-based MOF that can produce carbon-containing metal sulfides through appropriate sulfurization and annealing processes. Since the control of the morphology of nanostructured electrocatalysts plays a crucial role in optimizing catalytic activity, in this study, we synthesized rhombic dodecahedral, cubic, and plate-shaped ZIF-67 nanocrystals and utilized them as templates to fabricate Co3S4@CoMoS3 nanomaterials with various morphologies. These materials were characterized and subjected to electrochemical tests to evaluate their performance in the hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and electrocatalytic water splitting. The electrochemical measurements revealed that the plate-shaped Co3S4@CoMoS3–P exhibited the low overpotential for OER at 20 mA cm−2, with a value of 200 mV and a Tafel slope of 173 mV dec−1. Similarly, for HER at 10 mA cm−2, it showed an overpotential of 240 mV and a Tafel slope of 93 mV dec−1. Moreover, in the water splitting setup employing a dual electrode configuration, the plate-shaped Co3S4@CoMoS3–P achieved a voltage of 1.61 V at 20 mA cm−2, outperforming a commercial electrode combination (10% Pt/C//RuO2) in terms of water-splitting efficiency.

Catalysts for hydrogen evolution in universal-pH medium: Construction and structural optimization of Ni3S2/Co9S8/WS2 interface synergies

The performance of heterostructure nanomaterials depends on both the individual components characteristics and the interfaces synergistic effect. In this paper, a high-activity universal-pH HER catalyst, Ti felt supported nanoporous Ni3S2/Co9S8/WS2 (NiCoW-S) is synthesized by electrodeposition and vulcanization. Compared with Ni3S2/Co9S8, Ni3S2/Co9S8/WS2 heterostructure catalyst exhibits enhancement of intrinsic catalytic active center, charge transfer rate and stability in a wide pH range. Benefiting from the 3D porous structure and high-density heterostructure active edge sites, NiCoW-S shows good stability. And Moreover, it only needs 35 and 145 mV to reach 10 mA cm−2 in 0.5 M H2SO4 and 1.0 M KOH, respectively. Based on the experimental analysis, the favorable synergistic effect of metal components and the formation of sulfur vacancies can enhance the conductivity of electron transfer, which promotes electron transfer at the active heterogeneous interface. It provides a reference for designing of advanced metal sulfide heterostructure for hydrogen production in the future.