Chalcogenide Research Articles

Pressure induced semimetal-to-metal transition and new structure of Ta2NiSe5 above 10 GPa

Previous studies of the transition metal chalcogenide Ta2NiSe5has identified two phase transitions occurring between 0-10 GPa, involving the excitonic insulator-to-semiconductor transition at 1 GPa and the semiconductor-to-semimetal transition at 3 GPa. However, there is still a lack of in-depth research on the changes in its physical properties changes above 10 GPa. In this study, Ta2NiSe5were investigated under high-pressure conditions using high-pressure x-ray diffraction and high-pressure x-ray absorption experiments. During the experimental process, a novel phase transition from the semimetal to the metal phase was observed between 10-60 GPa, specifically between 10-14 GPa, and the structure of the new phase was determined to be P21/m through first-principles calculations. This transition mechanism is attributed to the sliding of the weakly coupled layers of Ta2NiSe5within thea-cplane, leading to changes in the crystal lattice constants and symmetry. This research fills a gap in the understanding of Ta2NiSe5's crystal structure under high pressure and contributes to the broader field of transition metal chalcogenides.

Recent Advances in Transition Metal Chalcogenides Electrocatalysts for Oxygen Evolution Reaction in Water Splitting

Rapid industrial growth has overexploited fossil fuels, making hydrogen energy a crucial research area for its high energy and zero carbon emissions. Water electrolysis is a promising method as it is greenhouse gas-free and energy-efficient. However, OER, a slow multi-electron transfer process, is the limiting step. Thus, developing efficient, low-cost, abundant electrocatalysts is vital for large-scale water electrolysis. In this paper, the application and progress of transition metal chalcogenides (TMCs) as catalysts for the oxygen evolution reaction in recent years are comprehensively reviewed. The key findings highlight the catalytic mechanism and performance of TMCs synthesized using single or multiple transition metals. Notably, modifications through recombination, heterogeneous interface engineering, vacancy, and atom doping are found to effectively regulate the electronic structure of metal chalcogenides, increasing the number of active centers and reducing the adsorption energy of reaction intermediates and energy barriers in OER. The paper further discusses the shortcomings and challenges of TMCs as OER catalysts, including low electrical conductivity, limited active sites, and insufficient stability under harsh conditions. Finally, potential research directions for developing new TMC catalysts with enhanced efficiency and stability are proposed.

Applicability of Semiconductor Photocatalysts in Photoredox Reactions: Highlighting the Performance of Polymeric Carbon Nitrides in Radical Three‐Component Couplings

A set of five polymeric carbon nitrides (pCNs) made from diverse low‐molecular precursors was compared with metal chalcogenide and pnictogenide semiconductors for their effectiveness in visible light‐induced organic radical reactions. The productivity of the heterogenous photocatalysts in the decarboxylative Giese addition of N‐phenylglycine with cyclopentenone was studied at different irradiation wavelengths ranging from 380 nm to 450 nm, as well as in the deaminative radical donor‐acceptor‐donor (DAD) three‐component coupling of N‐benzyl pyridinium salts with N‐methylmaleimide and 1,1‐diarylethylenes. The heterogenous photocatalytic radical three‐component reactions were achieved in high diastereoselectivities and with high yields if the electronic and steric properties of the reactants were matched with the appropriate heterogeneous photocatalyst.

Bimetallic Sulfides Cr0.99V1.8S4 with Loosely Packed Structure: Exploring the Boundary of Conversion and Intercalation Sodium-Ion Storage Mechanism.

Metal sulfide electrodes for sodium-ion batteries face trade-offs among high capacity, fast kinetics, and stability. The challenge lies in breaking and restoring metal-sulfur bonds and allowing rapid ionic transport. Here we explore the boundary of conversion- and intercalation-type metal sulfides to develop ideal sodium-ion storage materials. We focus on sulfides of vanadium and chromium because of their adjacent atomic numbers but different energy storage mechanism. Among various sulfides of vanadium and chromium, a loosely packed bimetallic sulfide, Cr0.99V1.8S4, with cationic vacancies and metallic conductivity (4.28 S m-1), shows optimal sodium-ion storage performance: an initial Coulombic efficiency of 95.6%, a reversible capacity of 551 mAh g-1 at 1.6 C, and maintaining 100% capacity after 600 cycles at a high rate of 16-66 C.

Recent Developments in Synthesis Techniques and Microwave Absorption Performance of Materials Based on Molybdenum Disulfide (MoS<sub>2</sub>) with Metal Oxides: A Review

The widespread usage of various wireless equipment in many facets of life has significantly contributed to the serious pollution caused by electromagnetic radiation. Thankfully, scientists have created materials that can absorb microwave radiation and convert dangerous electromagnetic waves into other forms of energy, including heat energy. Many investigations regarding the development of materials that absorb microwaves with different constituents, morphologies, and architectures have been published recently. Microwave-absorbing materials (MAMs) are becoming more and more popular for use in a variety of aviation applications, including EMI prevention, information security, and reducing the risks of electromagnetic radiation to human health. Molybdenum di-sulphide (MoS2) is a transition metal sulphide extensively employed as a microwave absorption material (MAM) owing to its superior structural and physicochemical qualities. Because of its many flaws, huge specific surface area, and semiconductor qualities, MoS2 exhibits exceptional microwave loss properties. Using a number of various designs, MoS2 may efficiently boost the absorption and dispersion of microwaves inside the absorber. This study introduces the structure, characteristics, and synthesis method based on MoS2 material. The effectiveness of MoS2-based MAMs has been evaluated and analyzed in detail at the moment. Furthermore, the key problems and development challenges are examined, and the most recent advancements in MoS2-based MAMs are impartially assessed and discussed. As a result, it is anticipated that MoS2-based composites would provide excellent choices for very thin and light MAMs.

One-Step Synthesis CuCoNiSxO4−x Thio/Oxy Spinel on Ni Foam for High-Performance Asymmetric Supercapacitors

Mixed transition metal sulfides are promising materials for positive electrodes of asymmetric supercapacitors because they have a large potential for increasing the electrical characteristics of these devices. The paper presents the results of a study of a material based on spinel CuCoNiSxO4−x with both sulfide and oxide sublattices, prepared by a one-step hydrothermal method directly on nickel foam, forming an array of whiskers. Electrochemical studies showed that a positive electrode, CuCoNiS2O2, exhibited a high specific capacitance of 3612 F g−1 at a current density of 1 A g−1. The assembled asymmetric supercapacitor with activated carbon as a negative electrode achieved a specific capacitance of 133.5 F g−1 at 1 A g−1 and a potential window of 1.7 V. Its energy density was 53.6 Wh kg−1 at a power density of 805 W kg−1 and the power density reached 17,000 W kg−1 at an energy density of 18.9 W h kg−1. The assembled device exhibits 52% of capacitance retention after the 20,000 cycles at a current density of 10 A g−1 with 97% coulombic efficiency. These results demonstrate that the CuCoNiSxO4−x system is competitive with other quaternary transition metal sulfides, and this type of spinel is a perspective electrode material for high-performance supercapacitors.

Triangular-shaped Cu-Zn-In-Se-based nanocrystals with narrow near infrared photoluminescence.

Tunable optical properties exhibited by semiconductor nanocrystals (NCs) in the near infrared (NIR) spectral region are of particular interest in various applications, such as telecommunications, bioimaging, photodetection, photovoltaics, etc. While lead and mercury chalcogenide NCs do exhibit exemplary optical properties in the NIR, Cu-In-Se (CISe)-based NCs are a suitable environment-friendly alternative to these toxic materials. Several reports of NIR-emitting (quasi)spherical CISe NCs have been published, but their more complex-shaped counterparts remain rather less explored. The emerging anisotropic nanomaterials have gained significant interest owing to their unique optical properties arising due to their specific shape. While several examples of non-spherical Cu-In-S-based NCs have been reported, examples of CISe-based anisotropic NCs are rather scarce, and those with intensive photoluminescence (PL) are not yet developed. In this work, we present a one-pot approach to synthesize quaternary Cu-Zn-In-Se (CZISe) triangular NCs with intensive PL in the NIR region. The NCs synthesized exhibit tetragonal crystal structure and, depending on the reaction conditions, are single triangular particles or stacks of triangular blocks of varied lateral sizes but rather uniform thickness. The synthesis involves the formation of In2Se3 seeds with subsequent incorporation of copper and growth of triangular CISe NCs, followed by the incorporation of zinc and the growth of a ZnS shell. Importantly, the PL band widths of the final core/shell heterostructured NCs are narrow, down to 102 meV, which is a rarely observed characteristic for this class of materials and can be attributed to their anisotropic shape and the absence of thickness and compositional inhomogeneities of their building blocks. The PL of the CZISe/ZnS NCs can be tuned in the range of 1082-1218 nm reaching a quantum yield of up to 40% by varying their size and composition. To the best of our knowledge, this is the farthest and the narrowest PL achieved for CISe-based NCs so far, which widens application perspectives of this material in NIR LEDs, bioimaging, and photovoltaics.

Structural Changes in Metal Chalcogenide Nanoclusters Associated with Single Heteroatom Incorporation.

Atomically precise nanoclusters (NCs) are promising building blocks for designing materials and interfaces with unique properties. By incorporating heteroatoms into the core, the electronic and magnetic properties of NCs can be precisely tuned. To accurately predict these properties, density functional theory (DFT) is often employed, making the rigorous benchmarking of DFT results particularly important. In this study, we present a benchmarking approach based on metal chalcogenide NCs as a model system. We synthesized a series of bimetallic, iron-cobalt chalcogenide NCs [Co6-xFexS8(PEt3)6]+ (x = 0-6) (PEt = triethyl phosphine) and investigated the effect of heteroatoms in the octahedral metal chalcogenide core on their size and electronic properties. Using ion mobility-mass spectrometry (IM-MS), we observed a gradual increase in the collision cross section (CCS) with an increase in the number of Fe atoms in the core. DFT calculations combined with trajectory method CCS simulations successfully reproduced this trend, revealing that the increase in cluster size is primarily due to changes in metal-ligand bond lengths, while the electronic properties of the core remain largely unchanged. Moreover, this method allowed us to exclude certain multiplicity states of the NCs, as their CCS values were significantly different from those predicted for the lowest-energy structures. This study demonstrates that gas-phase IM-MS is a powerful technique for detecting subtle size differences in atomically precise NCs, which are often challenging to observe using conventional NC characterization methods. Accurate CCS measurements are established as a benchmark for comparison with theoretical calculations. The excellent correspondence between experimental data and theoretical predictions establishes a robust foundation for investigating structural changes of transition metal NCs of interest to a broad range of applications.

Sensitization of Lanthanides with Metal Chalcogenides Nanocrystals: Night Vision Imaging and Security Encryption

AbstractThe sensitization of lanthanide ions by semiconductor nanocrystals offers promising potential for developing luminophores with high quantum yields, promising for light harvesting and imaging applications. This study introduces lanthanide‐doped CdS nanocrystals fabricated through a phosphine‐free method. Lanthanide ions such as Yb3+, Tm3+, Ho3+, and Er3+ are successfully doped into the CdS matrix, resulting in tunable NIR emissions ranging from 950 to 1600 nm. These nanocrystals exhibit visible–NIR emission with a total photoluminescence quantum yield of ≈41 ± 3%. Steady‐state and time‐resolved spectroscopic studies confirm the broadband sensitization of lanthanide ions by the CdS host. Binary ions‐doped CdS nanocrystals (CdS:Yb3+, Er3+/Ho3+/Tm3+) demonstrate both upconversion and downshifting processes within a single system. Furthermore, the NIR emission is enhanced under CdS excitation compared to direct lanthanide sensitization. Time‐resolved photoluminescence and transient absorption studies reveal the efficient energy transfer processes from CdS to the lanthanide dopants. Additionally, the NIR emission in CdS:Ln3+ embedded polymethyl methacrylate nanocomposites remains highly stable even months after fabrication, making them suitable for night vision imaging and security encryption. This study, therefore, advances the development of smart visible‐to‐NIR light sources for optoelectronic applications, including enhanced anti‐counterfeiting measures and night vision imaging.

MSene: A large family of two-dimensional transition metal sulfides with MXene structure

MSene: A large family of two-dimensional transition metal sulfides with MXene structure

Study of the Cathode/Electrolyte Interface in an All-Sulfide-Solid-State Battery Using Lithium-Rich Transition Metal Sulfide.

All-solid-state lithium batteries (ASSBs) are among the most promising energy storage technologies, particularly for electric vehicles, due to their enhanced safety. However, performances of these systems are still hindered by interfacial side reactions at electrode/electrolyte interfaces, especially when sulfide electrolytes are used, and additional issues of mechanical nature. In this work, an ASSB system composed of an argyrodite (Li5.7PS4.7Cl1.3) electrolyte, a lithium-rich sulfide cathode (Li1.2Ti0.8S2) operating at moderate voltage, and a lithium metal anode is investigated. The positive electrode/electrolyte interface is scrutinized during several battery cycles using X-ray photoelectron spectroscopy (XPS) via two complementary approaches (ex situ and in situ). We show that both titanium and sulfur species contribute to the electrochemical process without any detectable degradation of the electrolyte after 20 cycles and without the use of any protective coating. These results suggest that the electrochemical performances of such an all-sulfide system are not limited by the cathode/electrolyte reactivity, opening a promising route for the development of specific cathode materials adapted to sulfide electrolytes.

Non-Enzymatic Electrochemical Glucose Sensors Based on Metal Oxides and Sulfides: Recent Progress and Perspectives

With the sudden advancement of glucose biosensors for monitoring blood glucose levels for the prevention and diagnosis of diabetes, non-enzymatic glucose sensors have aroused great interest owing to their sensitivity, stability, and economy. Recently, researchers have dedicated themselves to developing non-enzymatic electrochemical glucose sensors for the rapid, convenient, and sensitive determination of glucose. However, it is desirable to explore economic and effective nanomaterials with a high non-enzymatic catalysis performance toward glucose to modify electrodes. Metal oxides (MOs) and metal sulfides (MSs) have attracted extensive interest among scholars owing to their excellent catalytic activity, good biocompatibility, low cost, simple synthesis process, and controllable morphology and structure. Nonetheless, the exploitation of MOs and MSs in non-enzymatic electrochemical glucose sensors still suffers from relatively low conductivity and biocompatibility. Therefore, it is of significance to integrate MOs and MSs with metal/carbon/conducive polymers to modify electrodes for compensating the aforementioned deficiency. This review introduces the recent developments in non-enzymatic electrochemical glucose sensors based on MOs and MSs, focusing on their preparation methods and how their structural composition influences sensing performance. Finally, this review discusses the prospects and challenges of non-enzymatic electrochemical glucose sensors.

Solvent Selection as a Key Factor in the Performance of Semitransparent Heterojunctions Composed of Hydrogenated Nanotubes and Bismuth Sulfides.

Research on titanium nanotubes modified with metal sulfides, particularly bismuth sulfide (Bi2S3), aims to create heterostructures that efficiently absorb sunlight and then separate photogenerated charge carriers, thereby enhancing the energy conversion efficiency. This study shows a key role of solvent used for sulfide and bismuth salt solutions used during successive ionic layer adsorption and reaction (SILAR) onto the morphology, structure, and photoresponse of the heterojunction where one element is represented by semitransparent titania nanotubes (gTiNT) and the second is Bi2S3. Using 2-methoxyethanol and methanol during SILAR, results in remarkably photoactive 3D heterostructure and recorded photocurrents were 44 times higher compared to bare titania nanotubes. Additionally, methanol- and 2-methoxyethanol-based processing allowed uniform deposition of the sulfide, which was not reached for other solvents. XPS studies not only confirm formation of bismuth sulfides but also indicate that BixTiyOz compound can arise that can affect both stability and photoactivity of the electrode material.

Preparation and Lithium Storage Properties of MOF‐Derived Bimetallic Sulfide ZnxInyS/MXene Composites

Nanostructured metal sulfides (MSs) are considered promising anode materials for Li‐ion batteries (LIBs) due to their high specific capacity and abundant raw material resources. However, the practical application of these materials faces challenges such as poor conductivity and volume expansion. To address these issues and enhance the performance of LIBs, it is crucial to tackle the structural design problem associated with ZnxInyS anode material. The utilization of metal sulfides derived from metal‐organic frameworks (MOFs) not only improves conductivity but also mitigates the issue of volume expansion in metal sulfides. Furthermore, connecting the metal sulfides derived from MOF to various conductive substrates can further enhance their conductivity. Two‐dimensional transition metal carbides and nitrides (MXenes), a novel type of 2D material with plentiful functional groups and chemical properties, offer great potential. In this study, we have strategically constructed ZnxInyS/MXene heterostructures by combining the advantages of 2D Ti3C2TX nanosheets and bimetallic MOF structures. The results demonstrate that due to the synergistic effect between MXene and heterostructure, a significant number of lattice defects and ample buffer space are provided, resulting in excellent lithium storage performance and fast ion diffusion kinetics for the electrode.

Ferroelectricity with concomitant Coulomb screening in van der Waals heterostructures.

Interfacial ferroelectricity emerges in non-centrosymmetric heterostructures consisting of non-polar van der Waals (vdW) layers. Ferroelectricity with concomitant Coulomb screening can switch topological currents or superconductivity and simulate synaptic response. So far, it has only been realized in bilayer graphene moiré superlattices, posing stringent requirements to constituent materials and twist angles. Here we report ferroelectricity with concomitant Coulomb screening in different vdW heterostructures free of moiré interfaces containing monolayer graphene, boron nitride (BN) and transition metal chalcogenide layers. We observe a ferroelectric hysteretic response in a BN/monolayer graphene/BN, as well as in BN/WSe2/monolayer graphene/WSe2/BN heterostructure, but also when replacing the stacking fault-containing BN with multilayer twisted MoS2, a prototypical sliding ferroelectric. Our control experiments exclude alternative mechanisms, such that we conclude that ferroelectricity originates from stacking faults in the BN flakes. Hysteretic switching occurs when a conductive ferroelectric screens the gating field electrically and controls the monolayer graphene through its polarization field. Our results relax some of the material and design constraints for device applications based on sliding ferroelectricity and should enable memory device or the combination with diverse vdW materials with superconducting, topological or magnetic properties.

Three Dimensional CNTs Interweaved Layered MnTe Nanoparticles as a New Cathode For Aqueous Zinc Ion Battery.

Currently, the development of suitable transition metal chalcogenides (TMDs) for aqueous zinc ion batteries (AZIBs) is plagued by the terrible conductivity and electrochemical properties. Herein, a one-step ball milling method is applied to enhance the conductivity of commercial MnTe cathode by constructing three dimensional (3D) carbon nanotubes (CNTs) interweaved MnTe nanoparticles (abbreviated as MnTe@CNTs), which can achieve ultrafast ion conduction. The stable electrochemistry properties benefit from the synergistic effects between layered MnTe and 3D CNTs, which can improve the electrons/ions diffusion kinetics as cycling. So MnTe@CNTs achieves a ultra-high capacity of 427.2 mAh g-1 at 0.1 A g-1 and superior capacity retention of 97.6 % at 1 A g-1 over 200 cycles. Zinc-storage mechanisms can be revealed with the aid of operando XRD and ex situ XPS spectra. MnTe as a new cathode presents superior Zn-storage ability for high-performance AZIBs.

S, Se-Codoped Dual Carbon Coating and Se Substitution in Co-Alkoxide-Derived CoS2 Through SeS2 Triggered Selenization for High-Performance Sodium-Ion Batteries

The development of metal sulfides as anodes for sodium-ion batteries (SIBs) is significantly obstructed by the slow kinetics of the electrochemical reactions and the substantial volume changes on the cycling. Herein, we introduce a selenium-substituted cobalt disulfide embedded within a dual carbon–graphene framework (Se-CoS2/C@rGO) for high-performance SIBs. The Se-CoS2/C@rGO was prepared via a synchronous sulfurization/selenization strategy using Co-alkoxide as the precursor and SeS2 as the source of selenium and sulfur, during which the EG anions are converted in situ to a S, Se codoped carbon scaffold. The dual carbon–graphene matrix not only improves the electronic conductivity but also stabilizes the electrode material effectively. In addition, the Se substitution within the CoS2 lattice further improves the electrical conductivity and promotes the Na+ reaction kinetics. The enhanced intrinsic electronic/ionic conductivity and reinforced structural stability endow the Se-CoS2/C@rGO anode with a high reversible capacity (558.2 mAh g−1 at 0.2 A g−1), superior rate performance (351 mAh g−1 at 20 A g−1), and long cycle life (93.5% capacity retention after 2100 cycles at 1 A g−1). This work provides new insights into the development of stable and reversible anode materials through Se substitution and dual carbon encapsulation.

S-d Coupling-Induced Dynamic Off-Centering of Cu Drives High Thermoelectric Performance in TlCuS.

Seeking new and efficient thermoelectric materials requires a detailed comprehension of chemical bonding and structure in solids at microscopic levels, which dictates their intriguing physical and chemical properties. Herein, we investigate the influence of local structural distortion on the thermoelectric properties of TlCuS, a layered metal sulfide featuring edge-shared Cu-S tetrahedra within Cu2S2 layers. While powder X-ray diffraction suggests average crystallographic symmetry with no distortion in CuS4 tetrahedra, the synchrotron X-ray pair distribution function experiment exposes concealed local symmetry breaking, with dynamic off-centering distortions of the CuS4 tetrahedra. The Cu off-centering is driven by the on-site coupling of filled 3d and unoccupied 4s orbitals (s-d) of Cu through a second-order Jahn-Teller mechanism. Bond softening by the p-d* (S-3p and Cu-3d) antibonding interaction coupled with dynamic off-centering distortions causes significant anharmonicity in the lattice, which acts as a phonon-blocking mechanism conducive to ultralow lattice thermal conductivity (κlat) (∼0.35-0.23 W m-1 K-1 in the ∼296-573 K temperature range) in TlCuS. The synergy between low κlat and multiband electronic structure leads to thermoelectric figure-of-merits (zT) of ∼1 and ∼1.3 at 573 K for pristine TlCuS and TlCu0.98S, respectively, underscoring the potential of metal sulfides as promising high-performance thermoelectrics.

Advances of immunosensors based on noble metal composite materials for detecting procalcitonin.

Procalcitonin (PCT) is a reliable biomarker for diagnosing and monitoring bacterial infections and sepsis. PCT exhibits good stability both in vivo and in vitro, and its levels drastically increase in response to bacterial infection or inflammatory reactions in the human body, making it a dependable indicator for sepsis diagnosis and monitoring with significant implications for clinical diagnosis and treatment guidance. Currently, immunosensors are widely utilized in PCT detection due to their high sensitivity and low detection limits. Noble metals, because of their excellent electronic conductivity, biocompatibility, and superior physicochemical properties, are extensively combined with other materials to play a pivotal role in the construction of PCT immunosensors. This review summarizes the research progress on PCT antigen immunosensors based on noble metal composite materials, encompassing the classification and principles of immunosensors. Starting from noble metals, which are widely used as electrode materials in sensors, the review categorizes and discusses the carbon materials, metal oxides, metal sulfides, and other composites with noble metals. The reviewalso elaborates on the influence of sensitive materials on the performance of immunosensors. Finally, the review discusses and anticipates the challenges and future opportunities for the research on PCT antigen immunosensors using noble metal-composite nanomaterials, providing new insights and directions for their application in the treatment and clinical management of sepsis and other diseases.

Research on the Performance Optimization of Molybdenum Disulfide for Multifunctional Applications

Molybdenum disulfide (MoS2), as a typical transition metal chalcogenide compound, has emerged as a research hotspot in nanomaterials due to its excellent electrochemical properties and catalytic activity. However, conventional MoS2 exhibits certain limitations in terms of its catalytic performance, electrical conductivity, and cycling stability. To address these issues, this paper aims to explore the improvement of the multifunctional performance of MoS2 via different performance optimisation strategies, such as heteroatom doping, semiconductor composites, as well as metallic and non-metallic loading. By reviewing and analyzing the relevant literature on the performance enhancement of MoS2 in recent years, this paper summarizes the specific applications and effects of these optimization strategies, highlighting that they significantly improve the performance of MoS2 in fields such as optics, electrochemical catalysis, lithium batteries, and supercapacitors, particularly in terms of catalytic activity, electrical conductivity, and cycling stability. The results indicate that the optimisation of MoS2 performance provides an important theoretical basis and practical guidance for its application in energy storage and catalytic hydrogen evolution.