Transition Metal Tellurides Research Articles

Fabrication of NbTe2@rGO nanosheet by hydrothermal route for cost-effective supercapacitor electrode

The expansion of energy storage devices with extensive stability and high energy density is a crucial area of research that requires immediate attention. In light of these requirements, it was worth noting that supercapacitor (SCs) exhibit great potential as viable options for achieving these demands. Supercapacitor (SCs) despite their potential currently exhibit energy density levels that fall short of the necessary threshold for long-term applications. This limitation primarily stems from the challenge of identifying the ideal materials to enhance their performance. However, transition metal tellurides have a well-studied group of materials that have garnered noticeable consideration because of high energy density. Herein, we present a novel hydrothermal method that involves the fabrication of reduced graphene oxide (rGO) nanosheet combined with niobium telluride (NbTe2) material. However, the NbTe2@rGO nanohybrid's specific capacitance (Csp) was 1475 F g−1, which was approximately twice as high as the specific capacitance of the NbTe2 (667 F g−1) electrode with a specific capacity of 826 C/g at 1 A g−1 which could be ascribed to interconnection between nanoparticles and nanosheets in the NbTe2@rGO nanohybrid with lower Rct = 0.02 Ω and outstanding cycling stability even after undergoing 7000th cycles with a capacitance retention of (97 %). The NbTe2@rGO nanohybrid demonstrated an impressive power density of 285 W kg−1 and energy density of 22 Wh kg−1 at 1 A g−1 in its symmetric two-electrode performance. The findings of this investigation suggested that NbTe2@rGO nanohybrid exhibits promising material for future energy storing devices.

Solution Synthesis and Diffusion-Mediated Formation Pathway of NbTe4 Particles.

NbTe4 is an important material because of its fundamental low-temperature electronic behavior and its potential interest for thermoelectric, catalytic, and phase-change applications, especially as nano- and microscale particles. As a tellurium-rich group V transition metal telluride, bulk NbTe4 is typically synthesized through high-temperature solid-state or metal flux reactions and NbTe4 films can be made by sputtering and annealing, but NbTe4 is generally not amenable to the lower-temperature solution-based syntheses that yield small particles. Here, we demonstrate a solvothermal route to NbTe4 particles that is based on mainstream colloidal nanoparticle synthesis. We find that the reaction proceeds in situ through a multistep pathway that begins by first forming elemental tellurium needles. NbTe4 then deposits on the surface of the tellurium needles through a diffusion-based process. Time-point studies throughout the reaction reveal that crystallographic relationships between Te and NbTe4 define how the diffusion-based reaction proceeds and help to rationalize the morphology of the resulting NbTe4 particles. As synthesized, NbTe4 particles exhibit a surface consisting of predominantly Nb-Te and reduced NbOx species, but after storage, surface oxidation transforms these species to primarily Nb2O5 and TeO2, while the NbTe4 remains unchanged. These synthetic capabilities and reaction pathway insights for NbTe4, made using a solvothermal method, will help to advance future studies on the properties and applications of this and related tellurides.

Solid Lithiation and Exfoliation for Scalable Synthesis of Two-Dimensional Nanosheets toward Industrialization.

Two-dimensional (2D) materials show intriguing and diverse properties in different fields, stimulating chemists to develop synthetic and functional methodologies for producing solution-processable nanosheets on a large scale. However, it is still challenging to prepare 2D materials for industrial applications without sacrificing their lab-scale properties. Solid lithiation and exfoliation can achieve the hundred-gram-scale production of transition metal telluride nanosheets, making it one of the most effective strategies for mass production of 2D nanomaterials. In this Perspective, we highlight the advantages, propose the challenges, and discuss the opportunities of solid lithiation and exfoliation as a promising and commercially viable production method for 2D nanomaterials.

Superconductivity, antiferromagnetism, and charge density waves in ZrTe3 intercalated with Terbium

The uniaxial compound ZrTe3 displays a complex charge density wave (CDW) ground state below ≈ 63 K. Here we report that Tb intercalated ZrTe3 single crystals display superconductivity with Tc ≈ 5.4 K. The effect of the Tb additions to the superconducting properties, magnetism, and CDW are probed by means of measurements of electrical resistivity (ρ), thermoelectric potential (S), and Hall effect. The temperature dependence of the upper critical field (Hc2) could be fit with a two-band model. The magnetic susceptibility measurements suggest that upon the addition of Tb an antiferromagnetic order is developed with ordering temperature of TN ≈ 4.0 K. Tb doping's enhancing effect on Tc suggests promising paths for future research involving lanthanide dopants in transition metal tellurides.

Fast and robust potassium storage enabled by controllable hierarchical CoTe2/MoS2@C nanorods with semi-coherent heterogeneous interfaces

Constructing heterostructures in a controllable manner stands as a pivotal strategy for enhancing the potassium-ion storage capabilities of transition metal tellurides. However, the challenge lies in achieving a favorable morphology while simultaneously regulating the heterogeneous interface. This study employs a straightforward one-step hydrothermal method to grow few-layer MoS2 nanosheets on CoTe2 nanorods, thereby fabricating a controllable hierarchical structure with a dense three-dimensional (3D) network of MoS2 nanosheets and abundant semi-coherent heterojunction interfaces with CoTe2. The CoTe2/MoS2 heterostructure exhibits abundant semi-coherent interfaces, at which a built-in electric field is formed that facilitates the migration of electrons and ions. A hierarchical structure of CoTe2/MoS2@C was further formed by carbon coating, that applies a dual constraint on CoTe2 to effectively alleviate its volume expansion during charge and discharge processes. Employed as the anode of potassium-ion batteries, the hierarchical structure of CoTe2/MoS2@C demonstrates a significant improvement in high-rate capacity, achieving a high specific capacity of 144.0 mAh g−1 at 5.0 A g−1. The material also enables excellent long-term cycling stability with a capacity decay of only 0.016 % per cycle up to 1800 cycles at 1.0 A g−1.

Solar enhanced oxygen evolution reaction with transition metal telluride.

The photo-enhanced electrocatalytic method of oxygen evolution reaction (OER) shows promise for enhancing the effectiveness of clear energy generation through water splitting by using renewable and sustainable source of energy. However, despite benefits of photoelectrocatalytic (PEC) water splitting, its uses are constrained by its low efficiency as a result of charge carrier recombination, a large overpotential, and sluggish reaction kinetics. Here, we illustrate that Nickel telluride (NiTe) synthesized by hydrothermal methods can function as an extremely effective photo-coupled electrochemical oxygen evolution reaction (POER) catalyst. In this study, NiTe was synthesized by hydrothermal method at 145°C within just an hour of reaction time. In dark conditions, the NiTe deposited on carbon cloth substrate shows a small oxygen evolution reaction overpotential (261mV) at a current density of 10mA cm-2, a reduced Tafel slope (65.4mV dec-1), and negligible activity decay after 12h of chronoamperometry. By virtue of its enhanced photo response, excellent light harvesting ability, and increased interfacial kinetics of charge separation, the NiTe electrode under simulated solar illumination displays exceptional photoelectrochemical performance exhibiting overpotential of 165mV at current density of 10mA cm-2, which is about 96mV less than on dark conditions. In addition, Density Functional Theory investigations have been carried out on the NiTe surface, the results of which demonstrated a greater adsorption energy for intermediate -OH on the catalyst site. Since the -OH adsorption on the catalyst site correlates to catalyst activation, it indicates the facile electrocatalytic activity of NiTe owing to favorable catalyst activation. DFT calculations also revealed the facile charge density redistribution following intermediate -OH adsorption on the NiTe surface. This work demonstrates that arrays of NiTe elongated nanostructure are a promising option for both electrochemical and photoelectrocatalytic water oxidation and offers broad suggestions for developing effective PEC devices.

Metal telluride nanosheets by scalable solid lithiation and exfoliation.

Transition metal tellurides (TMTs) have been ideal materials for exploring exotic properties in condensed-matter physics, chemistry and materials science1-3. Although TMT nanosheets have been produced by top-down exfoliation, their scale is below the gram level and requires a long processing time, restricting their effective application from laboratory to market4-8. We report the fast and scalable synthesis of a wide variety of MTe2 (M = Nb, Mo, W, Ta, Ti) nanosheets by the solid lithiation of bulk MTe2 within 10 min and their subsequent hydrolysis within seconds. Using NbTe2 as a representative, we produced more than a hundred grams (108 g) of NbTe2 nanosheets with 3.2 nm mean thickness, 6.2 µm mean lateral size and a high yield (>80%). Several interesting quantum phenomena, such as quantum oscillations and giant magnetoresistance, were observed that are generally restricted to highly crystalline MTe2 nanosheets. The TMT nanosheets also perform well as electrocatalysts for lithium-oxygen batteries and electrodes for microsupercapacitors (MSCs). Moreover, this synthesis method is efficient for preparing alloyed telluride, selenide and sulfide nanosheets. Our work opens new opportunities for the universal and scalable synthesis of TMT nanosheets for exploring new quantum phenomena, potential applications and commercialization.

Intrinsic room-temperature ferromagnetism in two-dimensional ternary transition metal tellurides CrX2Te4 (X = Al, Ga, and In)

A tremendous amount of research has witnessed the exploration of two-dimensional (2D) materials with intrinsic ferromagnetism and diverse physical properties. However, the low Curie temperature and deficient magnetic anisotropy hinder their practical applications in nanoscale spintronics. Based on first-principles calculations, we propose a new family of 2D ternary transition metal tellurides, CrX2Te4 (X = Al, Ga, and In), with both structural and magnetic stabilities at room temperature. Our calculations demonstrate that the 2D CrX2Te4 crystal exhibits the intrinsic 100% spin-polarized half-metallic feature with spin-up metallic and spin-down semi-conducting properties. With the remarkable magnetic moment of 4 μB per Cr atom, both 2D CrAl2Te4 and CrGa2Te4 crystals perform robust ferromagnetism with the out-of-plane magnetic anisotropy, while the 2D CrIn2Te4 crystal prefers the in-plane easy magnetization axis. The Monte Carlo simulation based on the 2D Heisenberg model shows that the critical Curie temperatures of the 2D CrAl2Te4, CrGa2Te4, and CrIn2Te4 crystals could reach 466, 431, and 536 K, respectively. Moreover, the magnetic exchange strength and magnetic anisotropy could be further enhanced by the in-plane biaxial strain. The novel electronic and magnetic features promote 2D CrX2Te4 (X = Al, Ga, and In) crystals as a new family of two-dimensional intrinsic ferromagnetic materials for next-generation advanced spintronics.

Ion adsorption promotes Frank-van der Merwe growth of 2D transition metal tellurides

Reliable synthesis methods for high-quality, large-sized, and uniform two-dimensional (2D) transition-metal dichalcogenides (TMDs) are crucial for their device applications. However, versatile approaches to growing high-quality, large-sized, and uniform 2D transition-metal tellurides are rare. Here, we demonstrate an ion adsorption strategy that facilitates the Frank-van der Merwe growth of 2D transition-metal tellurides. By employing this method, we grow MoTe2 and WTe2 with enhanced lateral size, reduced thickness, and improved uniformity. Comprehensive characterizations confirm the high quality of as-grown MoTe2. Moreover, various characterizations verify the adsorption of K+ and Cl- ions on the top surface of MoTe2. X-ray photoelectron spectroscopy (XPS) analysis reveals that the MoTe2 is stoichiometric without K+ and Cl- ions and exhibits no discernable oxidation after washing. This top surface control strategy provides a new controlling knob to optimize the growth of 2D transition-metal tellurides and holds the potential for generalized to other 2D materials.

Dual Design on Hierarchically Hollow MoTe2/C with Ion/Electron Channel Engineering for High-Performance Sodium Storage.

Transition-metal tellurides have been investigated as novel anode materials for application in sodium-ion batteries (SIBs) due to their rich active sites and unique and controllable layered nanostructures. However, the weak structural strength and inferior intercalation/deintercalation kinetics inhibit the development of transition-metal tellurides. In this work, MoTe2/C composites with two different hollow nanostructures are designed and prepared. By adjustment of the precursor structure, MoTe2/C-2 exhibits superior sodium-storage performance because of its uniquely hollow nanostructure with self-assembled 2D flexible nanosheets grown on the external surface. MoTe2/C-2 delivers a higher specific capacity (276 mAh g-1 at 0.1 A g-1 after 300 cycles), much more than MoTe2/C-1 (201 mAh g-1 at 0.1 A g-1 after 300 cycles), and exhibits a long-time cycling performance (131 mAh g-1 at 1 A g-1 after 2000 cycles). The excellent sodium-storage performance derived from the rational structure design is beneficial for shortening the ion paths, facilitating the sodiation/desodiation process, and reinforcing the intrinsic structural stability, thus boosting the reaction kinetics and prolonging the cycling life. Meanwhile, the assembled full-cell maintains 101 mAh g-1 at 0.1 A g-1 after 50 cycles and lights an electric watch. The findings provide several new views for preparation of more transition-metal tellurides with multi-ion/electron migration channel engineering.

Engineering Defect‐Rich Bimetallic Telluride with Dense Heterointerfaces for High‐Performance Lithium–Sulfur Batteries

AbstractRechargeable lithium–sulfur (Li–S) batteries have received ever‐increasing attention owing to their ultrahigh theoretical energy density, low cost, and environmental friendliness. However, their practical application is critically plagued by the sluggish reaction kinetics, shuttling of soluble polysulfide intermediates, and uncontrollable growth of Li dendrites. Herein, a bimetallic telluride electrocatalyst with dense heterointerfaces and rich defects embedded in hollow carbon polyhedron bunches (N⊂CoTe1‐x/ZnTe1‐y@NC, abbreviated as NCZTC) is rationally designed to simultaneously address the S cathode and Li anode problems. Both experimental and computational results substitute the integration of dense heterointerfaces and rich defects can synergistically modulate the electronic structure, enhance the electrical conductivity, promote the Li+ transportation, strengthen the polysulfides adsorption and improve the catalytic activity, thereby significantly accelerating the redox conversion kinetics and prevent the dendrite growth. Consequently, Li–S batteries with NCZTC‐modified separators demonstrate excellent electrochemical performance including high specific discharge capacity, remarkable rate capability, good long‐term cycling stability, and competitive areal capacity even at high sulfur loading and lean electrolyte conditions. This study not only provides valuable guidance for designing efficient sulfur electrocatalysts with transition metal tellurides but also emphasizes the importance of heterostructure design and defect engineering for high‐performance Li–S batteries.

A comprehensive review on advanced supercapacitors based on transition metal tellurides: from material engineering to device fabrication

The utilization of transition metal tellurides in supercapacitors holds great promise for advancing energy storage technology, offering high performance, stability, tunability, and sustainability.

MOF-derived scaffolds as electrode materials: a mini-review.

Metal-organic frameworks (MOFs) have unique properties but suffer from low conductivity and poor stability, limiting their use in energy storage. Transforming MOFs into other materials, like porous carbon or metal oxides/chalcogenides has been explored to overcome these limitations. However, these approaches still face issues such as dead volume and poor attachment due to insulating binders, causing high resistance and detachment. To address this, MOFs and their derived scaffolds directly on conductive substrates without binders have emerged. These electrodes offer simplified preparation, enhanced electron transfer, and improved interface contact. This mini-review focuses on MOF-derived scaffold electrodes using transition metal oxides, sulfides, selenides, and tellurides, which show promise in energy storage applications. Valuable insights, identified opportunities, and future suggestions in the field of MOF-derived scaffold electrodes and their applications in energy storage applications have been discussed.

General synthesis of magnetic binary transition metal telluride nanocrystals

We demonstrate a general approach to synthesize ferromagnetic Cr2Te3 and FeTe2, paramagnetic CoTe2−x and NiTe2−x, and antiferromagnetic MnTe2 nanocrystals.

3D Flower-like Nanospheres Constructed by Transition Metal Telluride Nanosheets as Sulfur Immobilizers for High-Performance Room-Temperature Na-S Batteries.

Room-temperature sodium-sulfur (RT Na-S) batteries hold immense promise as next-generation energy storage systems, owing to their exceptionally high theoretical capacity, abundant resources, eco-friendliness, and affordability. Nevertheless, their practical application is impeded by the shuttling effect of sodium polysulfides (NaPSs) and sluggish sulfur redox kinetics. In this study, an advanced strategy by designing 3D flower-like molybdenum telluride (MoTe2) as an efficient catalyst to promote sulfur redox for RT Na-S batteries is presented. The unique 3D flower-like MoTe2 effectively prevents NaPS shuttling and simultaneously offers abundant active catalytic sites facilitating polysulfide redox. Consequently, the obtained MoTe2/S cathode delivers an outstanding initial reversible capacity of 1015mAhg-1 at 0.1C, along with robust cycling stability of retaining 498mAhg-1 at 1C after 500 cycles. In addition, pouch cells are fabricated with the MoTe2 additive to deliver an ultrahigh initial discharge capacity of 890mAhg-1 and remain stable over 40 cycles under practically necessary conditions, demonstrating the potential application in the commercialization of RT Na-S batteries.

Directionally-Resolved Phononic Properties of Monolayer 2D Molybdenum Ditelluride (MoTe2) under Uniaxial Elastic Strain.

Understanding the phonon characteristics of two-dimensional (2D) molybdenum ditelluride (MoTe2) under strain is critical to manipulating its multiphysical properties. Although there have been numerous computational efforts to elucidate the strain-coupled phonon properties of monolayer MoTe2, empirical validation is still lacking. In this work, monolayer 1H-MoTe2 under uniaxial strain is studied via in situ micro-Raman spectroscopy. Directionally dependent monotonic softening of the doubly degenerate in-plane E2g1 phonon mode is observed with increasing uniaxial strain, where the E2g1 peak red-shifts -1.66 ± 0.04 cm-1/% along the armchair direction and -0.80 ± 0.07 cm-1/% along the zigzag direction. The corresponding Grüneisen parameters are calculated to be 1.09 and 0.52 along the armchair and zigzag directions, respectively. This work provides the first empirical quantification and validation of the orientation-dependent strain-coupled phonon response in monolayer 1H-MoTe2 and serves as a benchmark for other prototypical 2D transition-metal tellurides.

Design of a highly efficient heterostructure of transition metal tellurides with outstanding photocatalytic and antimicrobial potential

This work aimed to synthesize an effective material having greater potential to reduce water pollution caused by industrial waste and exhibit efficient antibacterial potential. The transition metals (Manganese-Mn, Zinc-Zn) and post transition metal (Tin-Sn) reacted with TeO2 in a stoichiometric ratio by adopting a solid-state reaction. The crystallite size of the synthesized compounds MnTeO3 (D1), ZnTeO3 (D2), and SnTe3O8 (D3) was measured by the Debye-Scherrer formula by extracting data from the FWHM. D1 and D2 exhibit the orthorhombic structure whereas D3 has a simple cubic structure and crystalline size was measured by FWHM i.e., 221 nm, 458 nm, and 153 nm. Catalytic degradation efficiency for the removal of MB dye was found to be in the range of 66%-73%. Additionally, these substances have strong antimicrobial action alongside both bacteria and fungi, such as Escherichia coli, Staphylococcus aureus with maximal zone inhibitions of 35.0 mm and 12.5 mm for each kind of bacterium. The highest antifungal activity of Mn integrated was estimated to be 37.2 mm versus Aspergillus niger and 15.1 mm alongside Coccidioides. According to the findings, the manufactured material has effective photocatalytic and antimicrobial activities.

High-efficiency sustainable energy driven alkaline/seawater electrolysis using a novel hetero-structured non-noble bimetal telluride nanorods

The development of non-noble, economical, and efficient electrocatalysts for water electrolysis will be inevitable for the upcoming green hydrogen economy. In consideration of this, we developed non-noble dual transition metal telluride nanorods through a facile single step hydrothermal method. The optimized CoMnTe2-1 nanorods requires a minimum overpotential of about 120 mV to reach a current density of 10 mA cm−2 in 1.0 M KOH towards the hydrogen evolution reaction (HER). Additionally, we evaluated the theoretical coordination calculations and investigated mechanistic HER pathways using density functional theory calculations. Furthermore, the fabricated water splitting device with CoMnTe2-1 anode displays a cell voltage of 1.60 V and 1.64 V to attain a current density of 10 mA cm−2 in alkaline and alkaline/seawater electrolytes, respectively. As a prototype, we also utilized renewable heat and mechanical energy to drive a self-powered water electrolysis device. This provides a promising path forward in designing an active and efficient bimetal telluride based electrocatalysts for green hydrogen production via alkaline/seawater electrolysis.

Crystal Growth and Physical Properties Evolution in Co‐Doped NiTe2 System

Transition metal tellurides have been widely studied for their diverse crystal structures and exotic physical properties such as large magnetoresistance, charge density waves, superconductivity, ferromagnetic and topological properties. NiTe2 has recently been found to be a Dirac semimetal, allowing it to achieve exotic properties by pressure and doping. A series of Ni1−xCoxTe2−δ single crystals are synthesized by the standard solid‐state reaction method. The energy‐dispersive X‐ray spectroscopy and X‐ray diffraction tests confirm Co is successfully doped into the crystal structure. The electrical transport measurements show typical metallic behaviors for all the samples. Magnetization measurements reveal that, in the doping range of x = 0.12–0.62, the samples exhibit a coexistence of antiferromagnetic and paramagnetic phases above the characteristic temperature Tt. By using the combined Curie–Weiss and spin‐wave model, the antiferromagnetic to ferromagnetic transition is found to occur as the temperature drops below Tt. The magnetic transition is attributed to the Te vacancies, which can be explained using the bound magnetic polaritons model. A magnetic phase diagram for Ni1−xCoxTe2−δ system is constructed.

Combined Defect and Heterojunction Engineering in ZnTe/CoTe2@NC Sulfur Hosts Toward Robust Lithium–Sulfur Batteries

AbstractLithium–sulfur batteries (LSBs) are feasible candidates for the next generation of energy storage devices, but the shuttle effect of lithium polysulfides (LiPSs) and the poor electrical conductivity of sulfur and lithium sulfides limit their application. Herein, a sulfur host based on nitrogen‐doped carbon (NC) coated with small amount of a transition metal telluride (TMT) catalyst is proposed to overcome these limitations. The properties of the sulfur redox catalyst are tuned by adjusting the anion vacancy concentration and engineering a ZnTe/CoTe2 heterostructures. Theoretical calculations and experimental data demonstrate that tellurium vacancies enhance the adsorption of LiPSs, while the formed TMT/TMT and TMT/C heterostructures as well as the overall architecture of the composite simultaneously provide high Li+ diffusion and fast electron transport. As a result, v‐ZnTe/CoTe2@NC/S sulfur cathodes show excellent initial capacities up to 1608 mA h g−1 at 0.1C and stable cycling with an average capacity decay rate of 0.022% per cycle at 1C during 500 cycles. Even at a high sulfur loading of 5.4 mg cm–2, a high capacity of 1273 mA h g−1 at 0.1C is retained, and when reducing the electrolyte to 7.5 µL mg−1, v‐ZnTe/CoTe2@NC/S still maintains a capacity of 890.8 mA h g−1 after 100 cycles at 0.1C.