Chalcogenide Research Articles

Enhanced Hydrogen Evolution Reaction Activity through Bimetallic Phosphide Integration in ReS2/Re2O7 Heterostructure

AbstractDeveloping a nonprecious and sustainable electrocatalyst in clean energy generation is quite noteworthy. Transition metal chalcogenides, oxides, and phosphides have emerged as promising candidates to substitute Pt‐based catalysts. In this study, we explore the catalytic potential of ReS2, a promising member of the transition metal dichalcogenides (TMD) family, for hydrogen evolution reactions (HER). The formation of rhenium oxide during the synthesis of ReS2 and further incorporation of a bimetallic phosphide NiCuP in a sequential hydrothermal synthesis reveals an excellent HER activity, as demonstrated by photoelectrochemical and electrochemical studies. Notably, the catalyst exhibits a significantly lower overpotential of −0.10 V (corresponding to −10 mA/cm2) and achieves a high current density of approx. −271 mA/cm2 at −0.79 V versus reversible hydrogen electrode (RHE) under light irradiation. The catalyst demonstrates high stability. These findings underscore the potential of NiCuP‐integrated ReS2/Re2O7 as a highly efficient and sustainable catalyst for HER.

Dual-functional MnS nanomaterials: Efficient adsorbent for phosphate removal and sonocatalyst for textile dye degradation

Naturally abundant, environmentally friendly alternatives for replacing the expensive lanthanum-based phosphate removal technique are sought after. Solocatalysis is an emerging area for water remediation. This study introduces a dual-functional MnS nanomaterial for removing phosphate ions and Congo Red textile dye. MnS nanomaterials were synthesized via a hydrothermal route. Batch adsorption experiments revealed a phosphate adsorption capacity of 160.73 mg P/g, commendable for adsorbent in its bare form. Thermodynamic parameters of the process indicated a spontaneous, exothermic process, confirming favourable adsorption. FTIR analysis confirmed the adsorption mechanism, which includes electrostatic attraction, surface complexation, and ion exchange. MnS maintained its adsorption capacity despite competing ions, demonstrating a selective affinity for phosphate ions. MnS showed high sonocatalytic efficiency, degrading Congo Red dye within 10 min of ultrasonic irradiation. The degradation mechanism of Congo Red dye in the sonocatalytic process is proposed. This novel metal chalcogenide material exhibits exceptional affinity for phosphate ions and Congo Red dye molecules, surpassing La-based adsorbents in efficacy. The results suggest that MnS nanomaterials are promising for practical applications in phosphate removal and textile dye degradation from wastewater.

Structural and dynamical properties of two dimensional disordered metal chalcogenides AB (A [formula omitted] Zn, Cd; B [formula omitted] S, Se): A classical molecular dynamic study

In recent years, the synthesis of two-dimensional (2D) materials, particularly the crystalline and disordered phases of 2D transition metal chalcogenides (TMCs), has gained considerable attention due to their wider electronic band gaps. This distinctive feature is pivotal in shaping their potential applications in solar cells, sensors, field-effect transistors (FETs), and photocatalysis for water decomposition. In the present study, we report molecular dynamics simulation of 2d disordered configuration of ZnX and CdX (X: S, Se) compounds using the Stillinger–Weber potential. We have explored their structural features by calculating their radial distribution functions and ring statistics. These systems are thermodynamically stable. The disordered network with numerous voids in these compounds play a pivotal role in lowering their melting temperature compared to their 2D crystalline counterparts, which falls within the range of 600 K to 700 K. The phonon density of states for all these systems shows a higher number of lower frequency (acoustic) modes than optical modes, which is understandably due to the presence of open regions and 2-fold sites in such systems.

Photocarrier relay modulating solar CO2-to-Syngas conversion

Solar-driven syngas generation by CO2 reduction provides a sustainable strategy to produce renewable fossil fuels. Nevertheless, this promising approach often suffers from tough CO2 activation, sluggish reaction kinetics and complex selectivity. Herein, we exquisitely constructed spatially directional charge transport channel over two-dimensional transition metal chalcogenide (TMC)-based heterostructure via a facile and universal electrostatic self-assembly method. Tailor-made positively charged non-conjugated insulating polymer of poly(diallyl-dimethyl-ammonium chloride) (PDDA) and negatively charged graphene oxide (GO) precursor as building blocks are controllably anchored on the TMC substrate, by which ultrathin PDDA layer is intercalated at the interface of GO and TMC. We ascertain that, in this customized sandwiched heterostructures, PDDA interim layer functions as an electron-relaying mediator, whilst graphene (GR) obtained from in-situ GO reduction during the photocatalytic reaction serves as a terminal electron-trapping reservoir, synergistically facilitating the spatially vectorial charge separation/migration over TMC, thus endowing the TMC/PDDA/GR heterostructures with conspicuously enhanced visible-light-driven photoactivity toward CO2-to-syngas conversion. Our work would inspire judicious ideas for finely modulating charge transfer over polymer-mediated photosystems and benefit our fundamental understanding of solar CO2 conversion.

Electrochemical biosensor based on copper sulfide/reduced graphene oxide/glucose oxidase construct for glucose detection

Due to the current increase in the number of people suffering from diabetes worldwide, how to monitor the blood glucose level in the human body has become an urgent problem to be solved nowadays. The electrochemical sensor method can be used for real-time glucose monitoring due to its advantages of real-time monitoring capability and high sensitivity. Reduced graphene oxide (rGO) has great potential for application in the field of sensors due to its advantages of large specific surface area, high stability, and good electrical and thermal conductivity. Meanwhile, the synergistic effect between two-dimensional transition metal sulfides and graphene can improve the electrochemical performance of materials due to their similar mechanical flexibility and strength. This article uses flake graphite, copper sulfate, and glucose oxidase (GOx) as raw materials to prepare CuS/rGO/GOx/GCE electrodes, and explores the performance of electrode electrocatalysis for glucose. The results showed that the prepared sensor was characterized by a low detection limit (1.75 nM) and a wide linear range (0.1-100 mM) for glucose detection, displaying a good overall detection performance, and its sensing mechanism and dynamic process were also investigated. In addition, the sensor has outstanding selectivity, anti-interference, repeatability, reproducibility and practicality.

Cu3.21Bi4.79S9: Bimetal superionic strategy boosts ultrafast dynamics for Na-ion storage/extraction

Traditional metal sulfides used as anodes for sodium-ion batteries are hindered by sluggish kinetics, which limits their rate performance. Previous attempts to address this issue focused on nanostructured configurations with conductive frameworks. However, these nanomaterials often suffer from low packing density and the tendency for nanoparticles to agglomerate, posing significant challenges for practical applications. To overcome these limitations, this study presents a novel bimetal superionic anode material Cu3.21Bi4.79S9, which effectively resolves the conflict between sluggish kinetics and micrometer-scale particle size. By leveraging the vacancies created by free Cu and Bi atoms, this material forms rapid migration channels during sodium insertion and extraction, significantly reducing the migration barriers for sodium ions. The development of micrometer-scale Cu3.21Bi4.79S9 enables ultrafast charging-discharging capabilities, achieving a reversible capacity of 325.5 mAh g−1 after 4000 cycles at a high rate of 45 C (15 A g−1). This work marks a significant advancement in the field by offering a solution to the inherent trade-off between high capacity and rate performance in coarse-grained materials, reducing the need for reliance on nanostructured configurations for next-generation high-capacity anode materials.

Acidophilic sulphate-reducing bacteria: Diversity, ecophysiology, and applications.

Acidophilic sulphate-reducing bacteria (aSRB) are widespread anaerobic microorganisms that perform dissimilatory sulphate reduction and have key adaptations to tolerate acidic environments (pH <5.0), such as proton impermeability and Donnan potential. This diverse prokaryotic group is of interest from physiological, ecological, and applicational viewpoints. In this review, we summarize the interactions between aSRB and other microbial guilds, such as syntrophy, and their roles in the biogeochemical cycling of sulphur, iron, carbon, and other elements. We discuss the biotechnological applications of aSRB in treating acid mine drainage (AMD, pH <3), focusing on their ability to produce biogenic sulphide and precipitate metals, particularly in the context of utilizing microbial consortia instead of pure isolates. Metal sulphide nanoparticles recovered after AMD treatment have multiple potential technological uses, including in electronics and biomedicine, contributing to a cost-effective circular economy. The products of aSRB metabolisms, such as biominerals and isotopes, could also serve as biosignatures to understand ancient and extant microbial life in the universe. Overall, aSRB are active components of the sulphur and carbon cycles under acidic conditions, with potential natural and technological implications for the world around us.

Facile one-pot synthesis of Bi2S3 nanorod @ N, S co-doped carbon composite for high performance lithium ion batteries

Bismuth sulfide is favoured in lithium ion batteries due to its high specific capacity of 625 mAh/g. However, the Bi2S3 anode faces severe volume expansion problems during the lithium intercalation process, resulting in continuous electrode fragmentation and rapid degradation of lithium storage performance. In this study, Bi2S3 nanorod@N, S co-doped carbon composite prepared by a simple sintering method was used as the anode material for lithium ion batteries. 1D Bi2S3 nanorods with a length of 1 μm and a diameter of 50 nm were loaded in situ on 2D N, S co-doped carbon nanosheets. This unique structure can not only alleviate the volume change of bismuth sulfide, but also effectively shorten the diffusion distance of lithium ions, thereby improving the cycling stability and rate capability at the same time. The discharge capacity of Bi2S3@N, SC remained at 583.4 mAh g –1 after 400 cycles at 0.5 A g–1. Even at a high current density of 2 A/g, the discharge capacity of Bi2S3@N, SC still reached 374.3 mAh g –1. This simple method also can be extended to the preparation of other metal sulfide composites.

Se-Doping on Co4S3 Cathode Based on Soft Anion Chemistry to Enhance Magnesium Storage Performance.

Rechargeable magnesium batteries (RMBs) have gradually got attention due to the high theoretical capacity, low cost and high security. However, the lack of suitable cathode materials has been a major obstacle to the development of RMBs. Transition metal sulfides (TMSs) have been studied extensively because of their high theoretical specific capacity and other advantages. However, the diffusion rate of Mg2+ in TMSs is slow and side reactions are easy to occur. In this work, soft anion doping strategy was adopted at Co4S3 cathode material. After doping the appropriate content of Se, it showed the specific capacity of 248 mAh g-1 at a current density of 100 mA g-1. The mechanism of magnesium storage was investigated by ex-situ technique. This work laid a foundation for researching cobalt-based sulfide in cathode materials of RMBs.

Exfoliated MoS2 anchored on graphene oxide nanosheets for enhancing thermoelectric properties of single-walled carbon nanotubes

Carbon nanotubes-based thermoelectric materials with high electrical conductivity (σ) and excellent mechanical properties have promising applications in flexible wearable devices. Two-dimensional transition metal sulfide MoS2 has been used to enhance the thermoelectric properties of carbon nanotubes due to its high Seebeck coefficient (S). However, MoS2 nanosheets are prone to agglomeration due to their high specific surface area, which causes lower doping efficiency. In this work, MoS2@GO hybrids are successfully fabricated using a hydrothermal in-situ growth method to anchor exfoliated MoS2 on graphene oxide (GO) nanosheets, and MoS2@GO hybrids significantly enhance the interfacial interaction between MoS2 and single-walled carbon nanotubes (SWCNT), improve the carrier mobility, lead to a simultaneous enhancement of the S and the σ. The maximum S value of MoS2@GO/SWCNT is 42.3 ± 0.2 μV K-1, the σ is 1173.2 ± 45.6 S cm-1, and an optimum power factor (PF) of 208.8 ± 8.5 μW m-1 K-2 is obtained at room temperature, which reaches 261.3 ± 10.2 μW m-1 K-2 at 385 K. For application demonstration, a thermoelectric device is assembled by connecting six pairs of p-type MoS2@GO/SWCNT and n-type copper sheets in series, which demonstrates an open-circuit voltage of 17.4 mV and an output power of 2.1 μW under a temperature difference of 50 K. Therefore, this study enriches the design and synthesis strategy of exfoliated MoS2 and provides a new approach for the development of high-performance SWCNT-based thermoelectric materials, which has important potential applications in the field of wearable electronics.

Promoting elemental mercury immobilization performance from smelting flue gas over a wide temperature range via cobalt-doped copper sulfide adsorbents

Copper sulfide (CuS) sorbent exhibits great potential for gaseous elemental mercury (Hg0) decontamination, but it still suffers from a narrow operating temperature. Therefore, designing advanced CuS sorbents that have a high activity level for capturing Hg0 and thermal stability at a high temperature range is challenging. Herein, we propose a metal doping strategy to fabricate a bimetallic sulfide adsorbent. Benefiting the unique structure and composition, a mesoporous structure and an abundance of unsaturated sulfur sites ensure that CuxCo(1–x)Sy provides a desirable level of adsorption for Hg0. The experimental results indicate the optimum Co doping mass concentration of 5 %. The Cu0.95Co0.05Sy not only performs satisfactory Hg0 adsorption at elevated temperatures (Hg0 average adsorption efficiency of over 97.3 %, Hg0 average adsorption rate of over 2.7 μg/g/min), but also presents an exciting regeneration and recycle performance (a Hg0 adsorption efficiency of over 94 % after 10 cycles). The adsorption capacity of Cu0.95Co0.05Sy at the breakthrough threshold of 25 % reaches 5.22 mg/g, surpassing most of metal sulfide sorbents for Hg0 immobilization at 150 °C. As far as Hg0 adsorption is concerned, the composition of typical smelting flue gases has almost no effect. According to further studies, unsaturated coordination short-chain sulfur (S22−) sites are essential for adsorption of Hg0 and are capable of directly forming α-HgS from Hg0. In both the contrast experiment and density functional theory calculations, the cobalt doping strategy enhances the thermal stability of the active S22− ligand and the Hg0 adsorption properties. This study not only provide a prospective adsorbent for Hg0 sequestration at wide temperature range, but also explores a method of utilizing gaseous contaminants for resource utilization.

Controlled Synthesis and Phase Transition Mechanisms of Palladium Selenide: A First-Principles Study.

Using density functional theory, we carefully calculated the relative stability of monolayer, few-layer, and cluster structures with Penta PdSe2, T-phase PdSe2, and Pd2Se3-phase. We found that the stability of Penta PdSe2 increases with the number of layers. The Penta PdSe2, T-phase PdSe2, and Pd2Se3 monolayers are all semiconducting, with band gaps of 1.77, 0.81, and 0.65 eV, respectively. The formation energy of palladium selenide clusters with different phase structures is calculated, considering the cluster size, stoichiometry, and chemical environment. Under typical experimental conditions, Pd2Se3 phase clusters are found to be dominant, having the lowest formation energy among all of the phases considered, with this dominance increasing as cluster size grows. Adjusting the Pd-Se ratio in the environment allows for controlled synthesis of specific palladium selenide phases, providing theoretical insights into the nucleation mechanisms of PdSe2 and other transition metal chalcogenides.

Recent Advances in Engineering of 2D Layered Metal Chalcogenides for Resistive-Type Gas Sensor.

2D nanomaterials have triggered widespread attention in sensing applications. Especially for 2D layered metal chalcogenides (LMCs), the unique semiconducting properties and high surface area endow them with great potential for gas sensors. The assembly of 2D LMCs with guest species is an effective functionalization method to produce the synergistic effects of hybridization for greatly enhancing the gas-sensing properties. This review starts with the synthetic techniques, sensing properties, and principles, and then comprehensively compiles the advanced achievements of the pristine 2D LMCs gas sensors. Key advances in the development of the functionalization of 2D LMCs for enhancing gas-sensing properties are categorized according to the spatial architectures. It is systematically discussed in three aspects: surface, lattice, and interlayer, to comprehend the benefits of the functionalized 2D LMCs from surface chemical effect, electronic properties, and structure features. The challenges and outlooks for developing high-performance 2D LMCs-based gas sensors are also proposed.

Electronic structure investigation and anisotropic phonon anharmonicity in ternary ZrGeTe4 single crystals

Ternary two-dimensional (2D) transition metal chalcogenides have gained immense attention because of their ability to overcome the intrinsic limitations of their binary counterparts. Layered 2D materials are important for future electronic and photonic devices owing to their low structural symmetry and in-plane anisotropy with tunable bandgap. Herein, the electronic structure and detailed vibrational properties of bulk ZrGeTe4 layered single crystals were investigated using angle-resolved photoemission spectroscopy (ARPES) and Raman scattering (RS). The ARPES results revealed an anisotropic Fermi surface of different momentum along kx and ky from the zone center and an anisotropic band structure with varying band curvatures along the high-symmetry directions. Furthermore, the RS of ZrGeTe4 was investigated under different polarizations and varying temperatures. The polarized RS exhibited twofold and fourfold symmetry orientations in different configurations, revealing the anisotropic phonon dispersions for bulk ZrGeTe4. The observed softening of Raman modes was corroborated with the anharmonic phonon dispersion, which was further supported by our third-order force constant calculations of thermal transport using density functional theory. Low lattice thermal conductivity with increasing temperature is linked with enhanced phonon–phonon scattering, which is evident from the decreased phonon lifetime and peak linewidth. In addition to these fundamental aspects, the anisotropic nature and unique layered structure of such materials reveal their bright future for next-generation nanoelectronic applications.

Solvothermal syntheses, structures and properties of quaternary alkaline earth metal sulfides BaCu6Ge2S8 and BaCuAsS3

Two quaternary alkaline earth metal sulfides, BaCu6Ge2S8(1) and BaCuAsS3 (2), were synthesized under low-temperature solvothermal conditions. Compound 1 features a three-dimensional (3D) [Cu6Ge2S8]n2n- framework comprising CuS3, CuS4, and GeS4 units, with Ba2+ cations occupying the channels. Compound 2 exhibits a one-dimensional (1D) chained structure, with Ba2+ cations situated between the chains. Alkaline earth metal ions exhibit a structural directing effect that is distinct from that of other guest cations. Specifically, Compound 1 presents a rare instance of a 3D Cu-Ge-S framework formed by condensation of two parallel layers. Compound 2 is the first 1D A-Cu-As-S compound (where A represents guest cations). Additionally, compound 2 presents the first example of AⅡ-Cu-As-S (where AⅡ represents alkaline earth metal cations) compounds. Their optical properties and theoretical calculations were also investigated. Our results demonstrate that solvothermal synthesis is a promising method for obtaining multinary alkaline earth metal sulfides with diverse structures and properties.

Application of in-situ synthesized gelidium-like core-shell structure FeCo2S4@NiCo2S4/carbon paper composite on titanium mesh in counter electrode of liquid thin film solar cells

Design inexpensive and stable counter electrodes materials is great essential for accelerating the industrial application of dye-sensitized solar cells. Herein, transition metal sulfides FeCo2S4 and NiCo2S4 were in-situ synthesized into composite with core–shell structure on surface of carbon paper by hydrothermal method, and is used as CEs material of DSSCs. Besides, titanium mesh with lower resistivity is also used as a conductive base to prepare the CEs and reduce the series resistance of DSSCs. Therefore, after electrochemical analysis and photoelectric performance test, it is found that the photoelectric conversion efficiency of the DSSCs assembled with composite material CEs can be as high as 10.08 % (with the Jsc is 19.59 mA·cm−2, Voc is 0.796 V, FF is 0.65), which much higher than traditional Pt CEs (7.99 %) and other corresponding counterparts, indicating that the core–shell structure is more conducive to improving the catalytic activity of the material.

Unveiling the potential: Asymmetric supercapacitors with conductive polymers/Ti3C2Tx/Ni3S4 electrodes deliver high energy densities

Ti3C2Tx is considered a promising electrode material for supercapacitors due to its fast electronic properties, excellent hydrophilicity and mechanical properties. However, severe Ti3C2Tx nanosheet stacking reduces the exposed active sites and hinders the ion diffusion of Ti3C2Tx, leading to poor electrochemical performance. Here, we report a strategy for doping of Ti3C2Tx, in which the Ni3S4 and conducting polymer (CP) were selected as doping agent for Ti3C2Tx, and it is expected that metal sulfide and CP can overcome the defects of Ti3C2Tx. In this work, the conducting polymers were as polyaniline (PANI), polypyrrole (PPY) and poly(3,4-ethylenedioxythiophene) (PEDOT). As a result, the prepared composites exhibit superior multiplicative capacity with a capacitance of 2502 F g-1 (PANI/Ti3C2Tx/Ni3S4), 2440 F g-1 (PPY/Ti3C2Tx/Ni3S4), and 2620 F g-1 (PEDOT/Ti3C2Tx/Ni3S4), respectively. In addition, CP/Ti3C2Tx/Ni3S4// AC asymmetric supercapacitors were assembled with energy densities of 60.2 (PANI/Ti3C2Tx/Ni3S4), 86.7 (PPY/Ti3C2Tx/Ni3S4), and 53.4 (PEDOT/Ti3C2Tx//Ni3S4) Wh kg-1 at 1,500 W kg-1, respectively. This work develops a simple way to prepare the porous Ti3C2Tx film for supercapacitors with excellent electrochemical performance.

Harnessing dysprosium telluride/GPE as an effective electrode for energy storage and conversion

Hydrogen stands out as a clean alternative to fossil fuels, and its production via water electrolysis is promising, although the slow kinetics of the oxygen evolution reaction (OER) pose a significant challenge. Alongside energy conversion, the quest for effective energy storage remains critical. This study explores the potential of dysprosium telluride (Dy2Te3) as a highly efficient catalyst for OER and a supercapacitor electrode. The hydrothermally synthesized Dy2Te3 exhibits exceptional OER activity, characterized by an overpotential of 294 mV at 1.48 V vs. RHE, a low Tafel slope of 48 mV dec−1, and minimal interfacial resistance of 13 Ω. In a 1.0 M KOH solution, Dy2Te3 nanoparticles demonstrate outstanding supercapacitor performance, achieving a power density of 283.5 W kg−1, specific capacitance of 645.33 F g−1, and energy density of 22.8 Wh kg−1 at 1 A g−1. The high performance is attributed to enhanced electrical conductivity and a low impedance of 0.352 Ω in a three-electrode system. In a practical two-electrode configuration, Dy2Te3 nanoparticles deliver a specific capacitance of 479 F g−1, energy density of 94 Wh kg−1, and power density of 0.32 kW kg−1, with a reduced interfacial resistance of 1.03 Ω. These results underscore the potential of Dy2Te3 as a viable electrode material for both supercapacitors and water splitting, offering valuable insights into the application of lanthanide-based metal chalcogenides in energy technologies.

A general methodology for the in situ construction of MxSy@N,S-C composites from L-cysteine for sodium-ion battery applications

High-capacity metal sulfides have been extensively investigated as cathode materials for secondary batteries. Despite their high capacity, the redox potential of metal sulfides is limited to 2.7 V. Therefore, researchers explored its application as a negative electrode material and discovered its exceptional electrochemical performance. However, the conventional methods for synthesizing transition metal sulfides (TMS) inevitably require an external source of sulfur for secondary sulfidation, resulting in energy dissipation. In this study, L-cystine was adopted as a polydentate ligand for the synthesis of MxSy@N, SC metal-organic frameworks, which can confine the desired carbon, nitrogen, and sulfur sources within the framework. This approach facilitates one-step sintering to obtain nitrogen-doped transition metal sulfides. The structure composition and electrochemical reaction mechanism of FeS@N,S-C as the negative electrode in Na-ion batteries were studied through scanning electron microscopy (SEM)/transmission electron microscopy (TEM) and X-ray diffraction (XRD)/X-ray photoelectron spectroscopy (XPS) analysis. The electrochemical properties of FeS@N,S-C materials were test as an example. The FeS@N, SC composite exhibited a reversible Na+ storage capacity of 724.4 mAh g−1 at a current density of 200 mA g−1, and still maintained a reversible capacity of 600.7 mAh g−1 at a current density of 2000 mA g−1, demonstrating excellent rate performance. After 200 cycles, the material was still able to retain 97.3 % of the discharge specific capacity, demonstrating fine cycle performance. It shows that the FeS@N, SC composite has rapid electron conduction ability and high sodium ion diffusion coefficient. At the same time, a rapidly charge-discharge process can be achieved with a large capacitive contribution, indicating the great potential of this material as a sodium-ion battery.

Efficient Transition Metal Sulfide Electrocatalysts Prepared by Laser-Induced Precursor Decomposition

Efficient Transition Metal Sulfide Electrocatalysts Prepared by Laser-Induced Precursor Decomposition