Chemical synthesis of nanoparticles of nickel telluride and cobalt telluride and its electrochemical applications for determination of uric acid and adenine

ZIF-67 nanocubes assembly-derived CoTe2 nanoparticles encapsulated hierarchical carbon nanofibers enables efficient lithium storage

Tellurides are promising anode materials for lithium-ion batteries (LIBs) because of their high electronic conductivity and energy density. However, the slow kinetics and poor structural stability lead to decreased electrochemical performance. In this work, by utilizing the interface magnetization mechanism and assembly effect, high-performance CoTe2 nanoparticles encapsulated hierarchical N-doped porous carbon nanofibers were rationally designed and prepared (ES-CoTe2@NC) via facile tellurization of one-dimensional (1D) ZIF-67 nanocube assemblies. Benefiting from the synergistic effects of the unique structure and component, the ES-CoTe2@NC anode exhibits a high reversible capacity of 1020 mAh/g at 0.1 A/g after 200 cycles, along with excellent long-term cycling stability, retaining a capacity of 780 mAh/g at 1 A g-1 after 500 cycles. Notably, the ES-CoTe2@NC anode retains a remarkable capacity of 502 mAh/g even after 1000 cycles at a high current density of 5 A g-1, highlighting its exceptional cycling stability. Besides, the Full cell coupled with LiFePO4 cathode delivers a high reversible capacity of 151.1 mAh g-1 at 0.1 A g-1 with stable cycling performance. The kinetics analysis reveals that the ES-CoTe2@NC anode has high pseudocapacitive properties, high electronic conductivity, and fast Li+ diffusion capability. Moreover, the ex-situ characterization clarifies the conversion reaction mechanism of ES-CoTe2@NC. This work provides a facile but effective way to construct high-performance CoTe2-based electrodes.

Evolution of Metal Tellurides for Energy Storage/Conversion: From Synthesis to Applications

Metal telluride (MTe)-based nanomaterials have emerged as a potential alternative for efficient, highly conductive, robust, and durable electrodes in energy storage/conversion applications. Significant progress in the material development of MTe-based electrodes is well-sought, from the synthesis of its nanostructures, integration of MTes with supporting materials, synthesis of their hybrid morphologies, and their implications in energy storage/conversion systems. Herein, an extensive exploration of the recent advancements and progress in MTes-based nanomaterials is reviewed. This review emphasizes elucidating the fundamental properties of MTes and providing a systematic compilation of its wet and dry synthesis methods. The applications of MTes are extensively summarized and discussed, particularly, in energy storage and conversion systems including batteries (Li-ion, Zn-ion, Li-S, Na-ion, K-ion), supercapacitor, hydrogen evolution reaction (HER), oxygen evolution reaction (OER), oxygen reduction reaction (ORR), and CO2 reduction. The review also emphasizes the future prospects and urgent challenges to be addressed in the development of MTes, providing knowledge for researchers in utilizing MTes in energy storage and conversion technologies.

Controlling Phase in Colloidal Synthesis

A fundamental precept of chemistry is that properties are manifestations of the elements present and their arrangement in space. Controlling the arrangement of atoms in nanocrystals is not well understood in nanocrystal synthesis, especially in the transition metal chalcogenides and pnictides, which have rich phase spaces. This Perspective will cover some of the recent advances and current challenges. The perspective includes introductions to challenges particular to chalcogenide and pnictide chemistry, the often-convoluted roles of bond dissociation energies and mechanisms by which precursors break down, using very organized methods to map the synthetic phase space, a discussion of polytype control, and challenges in characterization, especially for solving novel structures on the nanoscale and time-resolved studies.

Rapid microwave-assisted synthesis and characterization of a novel CuCoTe nanocomposite material for optoelectronic and dielectric applications

In the realm of nanomaterial research, copper telluride and cobalt telluride have individually attracted considerable attention owing to their unique properties and potential applications. However, there exists a notable gap in the literature when it comes to the exploration of composite materials derived from these elements. From this point of view, a ternary CuCoTe nanocomposite was prepared using the microwave synthesis method. Various characterizations were performed by varying the power and irradiation time. X-Ray diffraction study and transmission electron microscopy analysis confirmed the polycrystalline nature of the material with Cu2Te and CoTe hexagonal phases. Field emission scanning electron microscopy images reveal nanoparticle-like morphology, which remains unchanged even when the time of irradiation increases. In addition, the nanoparticle size of the material lies in the range of 30-39 nm. The differential scanning calorimetry inferred various exothermic and endothermic peaks. Meanwhile, the optical analysis from the UV-visible study shows the red-shifted absorbance, enabling the material for semiconductor and photovoltaic devices. Furthermore, the optical bandgap of the material varies in the range from 2.45 to 3.61 eV, which reveals the tuneable bandgap desiring the material for various optoelectronic applications. The frequency-temperature-dependent dielectric study gives results for dielectric parameters, conductivity, and impedance behaviour. The material's dielectric constant, dielectric loss, and AC conductivity enhance with the increase in temperature. This behaviour of the material broadens the area of applicability in energy storage devices.

Electrochemical Sensors Based on Transition Metal Materials for Phenolic Compound Detection

Electrochemical sensors have been recognized as crucial tools for monitoring comprehensive chemical information, especially in the detection of a significant class of molecules known as phenolic compounds. These compounds can be present in water as hazardous analytes and trace contaminants, as well as in living organisms where they regulate their metabolism. The sensitive detection of phenolic compounds requires highly efficient and cost-effective electrocatalysts to enable the development of high-performance sensors. Therefore, this review focuses on the development of advanced materials with excellent catalytic activity as alternative electrocatalysts to conventional ones, with a specific emphasis on transition metal-based electrocatalysts for the detection of phenolic compounds. This research is particularly relevant in diverse sectors such as water quality, food safety, and healthcare.

RuSe2-CoTe Heterogeneous Surfaces Coated with NC Layer for Excellent HER Performance under Alkaline Condition

Electrocatalytic hydrogen production has been a promising high-purity hydrogen production technology, attracting a large number of researchers' research interest. Ru has a hydrogen binding capacity similar to Pt, but its price is far lower than Pt, making it a promising alternative to Pt. However, a single Se electronic structure modulation is not sufficient to enable RuSe2 to be used for practical applications on a large scale due to the lack of electrons. Therefore, choosing a suitable way to electronically modulate the Ru atoms in RuSe2 can effectively improve the activity of the catalyst. Cobalt telluride (CoTe) can significantly enhance electrocatalytic performance due to tellurium's low electronegativity and excellent metal properties. In this work, the NC layer possesses excellent electrical conductivity and CoTe acts as an electron donor to optimize the electronic structure locally and trigger electron transfer efficiently. The RuSe2-CoTe/NC electrode requires an overpotential of only 25.4 mV (10 mA cm-2), which is superior to that of RuSe2/NF (65 mV) and CoTe/NC (115 mV). Meanwhile, the Tafel slope of RuSe2-CoTe/NC (67.8 mV dec-1) was better than that of RuSe2/NF (113.6 mV dec-1) and CoTe/NC (209.5 mV dec-1), showing that the build-up of the superior heterojunction makes the RuSe2-CoTe/NC with better hydrogen evolution reaction (HER) reaction kinetics. In addition, after 30 h of long-term stability testing, no significant decrease in catalytic activity was observed, proving the good stability of the RuSe2-CoTe/NC catalyst.

Dependence of Transition-Metal Telluride Phases on Metal Precursor Reactivity and Mechanistic Implications

Modern bottom-up synthesis to nanocrystalline solid-state materials often lacks the reasoned product control that molecular chemistry boasts from having over a century of research and development. In this study, six transition metals including iron, cobalt, nickel, ruthenium, palladium, and platinum were reacted with the mild reagent didodecyl ditelluride in their acetylacetonate, chloride, bromide, iodide, and triflate salts. This systematic analysis demonstrates how rationally matching the reactivity of metal salts to the telluride precursor is necessary for the successful production of metal tellurides. The trends in reactivity suggest that radical stability is the better predictor of metal salt reactivity than hard-soft acid-base theory. Of the six transition-metal tellurides, the first colloidal syntheses of iron and ruthenium tellurides (FeTe₂ and RuTe₂) are reported.

Polymorphism of the Co-Te nanophases in mechanochemical synthesis

The mechanochemical synthesis of all cobalt tellurides' phases is demonstrated in this work. The samples had their structural, microstructural, and magnetic characterizations performed by X-ray powder diffraction, transmission electron microscopy, and magnetometry techniques. The initial atomic stoichiometries tested of Co₃₂Te₆₈ and Co₄₀Te₆₀ resulted in the synthesis of the γ-CoTe₂ Pnnm (marcasite), α-CoTe₂ Pa3̄ (pyrite), α-CoTe₂ P3̄m1 (CdI₂-like), and β-CoTe P6₃/mmc phases with different weight proportions in the sample. Modeling of the X-ray diffractograms employed conventional double-Voigt and crystallite shape-anisotropy DV approaches to show that the volumetric diameter average and true crystallite size of the diffraction domains are in the range of tens of nanometers. Transmission electron microscopy measurements also allowed distribution counting of the crystallite sizes via maximum caliper diameter. Electron diffraction experiments presented comparable structural parameters with Rietveld via the analysis of the Debye rings. A model using the Langevin approaches showed the phases to present both ferromagnetic and superparamagnetic contributions attributed to weakly-interacting metallic Co grains with magnetic domain sizes ranging between 2.3 and 4.0 nm. The phases' evolution with storage time was analyzed over two years and revealed to be stable regarding their structural and microstructural properties.

Tellurium-based chemical sensors

The various tellurium-based chemical sensors are described. This article focuses on four types of Tellurium sensors such as CdTe quantum dots-based sensor, Te thin films-based sensor, Te nanostructures or nanoparticles-based sensor, and TeO2-based sensor.

Recent advances of metal telluride anodes for high-performance lithium/sodium-ion batteries

Metal tellurides (MTs) have emerged as highly promising candidate anode materials for state-of-the-art lithium-ion batteries (LIBs) and sodium ion batteries (SIBs). This is owing to the unique crystal structure, high intrinsic conductivity, and high trap density of such materials. The present work delivers a detailed discussion on the latest research and progress associated with the use of MTs for LIBs/SIBs with a focus on reaction mechanisms, challenges, electrochemical performance, and synthesis strategies. Further, the prospects and future development of MT anode materials are discussed in terms of strategies to overcome the existing limitations. This review provides both an in-depth understanding of MTs and provides the driving force for expanding research on MTs for energy storage and conversion applications.

Cobalt Ferrite Nanocomposite as Electrochemical Sensor for The Detection of Guanine, Uric Acid and Their Mixture

Cobalt ferrite nanocomposite was synthesized and characterized by analytical techniques such as FESEM, EDS and XRD. The average crystallite size was found to be in the range of 10–12 nm with a cubic structure. Further, the nanocomposite was used for the detection of guanine (GU) and uric acid (UA) and found to be an efficient electrode modifier. The lower limit of detection for GU and UA was found to be 300 nM and 400 nM, respectively

A petal-shaped MOF assembled with a gold nanocage and urate oxidase used as an artificial enzyme nanohybrid for tandem catalysis and dual-channel biosensing

A facile one-pot precipitation method was employed to prepare a petal-shaped hybrid under mild conditions. The hybrid is composed of urate oxidase (UOx) encapsulated into a zeolite-like metal-organic framework (MOF) with the doping of a hollow gold nanocage (AuNC). As one of the MOF-enzyme composites, a UOx@MOF(AuNC) hybrid with the features of artificial nanoenzymes was developed as a novel dual-channel biosensing platform for fluorescence (FL) and electrochemical detection of uric acid (UA). As for FL biosensing, enzymatic catalysis of the hybrid in the presence of UA triggered tandem catalysis and oxidation reactions to cause FL quenching. UA was linearly detected in the 0.1-10 μM and 10-300 μM ranges, with the limit of detection (LOD) of 20 nM. As for electrochemical biosensing, the hybrid was dropped on a glassy carbon electrode (GCE) surface to construct a hybrid/GCE platform. Based on the redox reaction of UA on the platform surface, UA was linearly detected in the 0.05-55 μM range, with a LOD of 15 nM. Experimental results confirmed that the hybrid-based dual-channel biosensing platform enabled selective and sensitive responses to UA over potential interferents. The platform has an excellent detection capability in physiological samples. The dual-channel biosensing platform facilitates the exploration of new bioanalysis techniques for early clinical diagnosis of diseases.

Solvent-Free Mechanochemical Synthesis and Characterization of Nickel Tellurides with Various Stoichiometries: NiTe, NiTe2 and Ni2Te3

The paper reports the synthesis of nickel tellurides via a mechanochemical method from elemental precursors. NiTe, NiTe₂, and Ni₂Te₃ were prepared by milling in stainless steel vials under nitrogen, using milling times from 1 h to 12 h. The products were characterized by powder X-ray diffraction (pXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), dynamic light scattering (DLS), vibrating sample magnetometer (VSM), UV-VIS spectrometry, and thermal analysis (TGA and DSC). The products were obtained in the form of aggregates, several hundreds of nanometers in size, consisting of smaller nanosized crystallites. The magnetic measurements revealed a ferromagnetic behavior at room temperature. The band gap energies calculated using Tauc plots for NiTe, NiTe₂, and Ni₂Te₃ were 3.59, 3.94, and 3.70 eV, respectively. The mechanochemical process has proved to be a simple and successful method for the preparation of binary nickel tellurides, avoiding the use of solvents, toxic precursors, and energy-consuming reaction conditions.

Structural, microstructural and magnetic characterization of the β-CoTe nanophase synthesized by a novel mechanochemical method

This work reports an unprecedented mechanochemistry synthesis of β-CoTe and its systematic characterization through X-ray powder diffraction (XRPD), transmission electron microscopy (TEM), and magnetometry techniques. The mechanical alloying produced the desired material within 6 h along with minor impurities, showing good stabilization for higher milling times (15 h) and long-term storage. XRPD characterization employed the Rietveld profile fitting analysis with fundamental parameters analysis in a direct convolution approach, giving the material's structure and microstructure information. For the spherical shape, the diameter mass average of the crystallites furnished values around 13 nm with 1.1% of microstrain. The double-Voigt procedure also modeled a triaxial ellipsoid shape for the crystallite size and obtained a surface-weighted average value for its volume around 150 nm3. TEM images confirmed the nanometric size visually and showed the crystallites to aggregate in large particles hundreds of nanometers in size. Measuring hundreds of supposed crystallite sizes, we could achieve a numerical distribution of their sizes with an average of 16 nm. The magnetization analysis performed both experimentally and via numerical simulations showed that β-CoTe is predominantly superparamagnetic with a magnetic domain size compatible with the double-Voigt one.

Bio-assisted preparation of efficiently architectured nanostructures of γ-Fe2O3 as a molecular recognition platform for simultaneous detection of biomarkers

Magnetic nanoparticles of iron oxide (γ-Fe2O3) have been prepared using bio-assisted method and their application in the field of biosensors is demonstrated. Particularly in this work, different nanostructures of γ-Fe2O3 namely nanospheres (NS), nanograsses (NG) and nanowires (NW) are prepared using a bio-surfactant namely Furostanol Saponin (FS) present in Fenugreek seeds extract through co-precipitation method by following "green" route. Three distinct morphologies of iron oxide nanostructures possessing the same crystal structure, magnetic properties, and varied size distribution are prepared and characterized. The resultant materials are analyzed using field emission scanning electron microscopy, transmission electron microscopy, powder X-ray diffraction, X-ray photoelectron spectroscopy, vibrating sample magnetometer and Fourier transform infrared spectroscopy. Moreover, the effect of reaction time and concentration of FS on the resultant morphologies of γ-Fe2O3 nanostructures are systematically investigated. Among different shapes, NWs and NSs of γ-Fe2O3 are found to exhibit better sensing behaviour for both the individual and simultaneous electrochemical detection of most popular biomarkers namely dopamine (DA) and uric acid (UA). Electrochemical studies reveal that γ-Fe2O3 NWs showed better sensing characteristics than γ-Fe2O3 NSs and NGs in terms of distinguishable voltammetric signals for DA and UA with enhanced oxidation current values. Differential pulse voltammetric studies exhibit linear dependence on DA and UA concentrations in the range of 0.15-75 µM and 5 μM - 0.15 mM respectively. The detection limit values for DA and UA are determined to be 150 nM and 5 µM. In addition γ-Fe2O3 NWs modified electrode showed higher sensitivity, reduced overpotential along with good selectivity towards the determination of DA and UA even in the presence of other common interferents. Thus the proposed biosensor electrode is very easy to fabricate, eco-friendly, cheaper and possesses higher surface area suggesting the unique structural patterns of γ-Fe2O3 nanostructures to be a promising candidate for electrochemical bio-sensing and biomedical applications.

Hydrothermal synthesis of cobalt telluride nanorods for a high performance hybrid asymmetric supercapacitor

Cobalt telluride nanostructured materials have demonstrated various applications, particularly in energy generation and storage. A high temperature and reducing atmosphere are required for the preparation of cobalt telluride-based materials, which makes this a difficult and expensive process. The development of a facile route for producing the desirable nanostructure of cobalt telluride remains a great challenge. We demonstrated a simple hydrothermal method for preparing cobalt telluride nanorods (CoTe NRs) and telluride nanorods (Te NRs) for supercapacitor applications. The morphology of CoTe NRs and Te NRs was analyzed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The prepared CoTe NR electrode material exhibited a high specific capacity of 170 C g⁻¹ at a current density of 0.5 A g⁻¹ with an exceptional cyclic stability. The asymmetric supercapacitor was assembled using CoTe NRs and orange peel-derived activated carbon (OPAA-700) as a positive and negative electrode, respectively. The fabricated device delivered a high energy density of 40.7 W h kg⁻¹ with a power density of 800 W kg⁻¹ at 1 A g⁻¹ current density. When the current density was increased to 30 A g⁻¹, the fabricated device delivered a high power density of 22.5 kW kg⁻¹ with an energy density of 16.3 W h kg⁻¹. The fabricated asymmetric supercapacitor displayed a good cyclic stability performance for 10 000 cycles at a high current density of 30 A g⁻¹ and retained 85% of its initial capacity for after 10 000 cycles. The prepared materials indicate their applicability for high performance energy storage devices.

A one-step hydrothermal derived cobalt telluride nanorods and activated carbon-based hybrid asymmetric supercapacitor delivered a high energy (40.7 W h kg⁻¹) and power density (22.5 kW kg⁻¹) with an electrochemical stability of 85% for 10000 cycles.

Photoactivity and optical applications of organic materials containing selenium and tellurium

Sulfur-containing compounds, particularly derivatives of thiophene, are well studied for organic optoelectronic applications. Incorporating selenium or tellurium in place of sulfur imparts different physical properties due to the fundamental differences of these atoms relative to their lighter analogues. This has a profound influence on the properties of molecules and materials that incorporate chalcogens that may ultimately lead to new opportunities and applications. This mini-review will focus on the quantitative and qualitative photophysical characteristics of organic materials containing selenium and tellurium as well as their emerging applications as molecular photoactive species, including light-emitting sensors, triplet sensitizers, and beyond.

Nanosized iron telluride for simultaneous nanomolar voltammetric determination of dopamine, uric acid, guanine and adenine

Herein, an efficient electrochemical sensor based on nano-sized iron telluride material (FeTe₂) have been developed for the first time for simultaneous nanomolar determination of dopamine, uric acid, guanine and adenine molecules.

Synthesis and self-assembly of thiol-modified tellurophenes

An asymmetric thiol-modified tellurophene was designed and synthesized, and the ability of the compound to form a monolayer on a gold electrode was confirmed. The surface-active tellurophene was synthesized using Cadiot–Chodkiewicz coupling followed by ring closing and thiol modification. The tellurophene compound forms a monolayer on gold surfaces from a concentrated solution within 24 h. The ability of the compound to conjugate to gold is confirmed by X-ray photoelectron spectroscopy (XPS). A surface blocking experiment was used to evaluate the extent of formation of a monolayer on a gold electrode.

Gold nanocluster-based ratiometric fluorescent probes for hydrogen peroxide and enzymatic sensing of uric acid

A method is described for ratiometric fluorometric assays of H₂O₂ by using two probes that have distinct response profiles. Under the catalytic action of ferrous ion, the 615 nm emission of protein-stabilized gold nanoclusters (under 365 nm photoexcitation) is quenched by H₂O₂, while an increased signal is generated with a peak at 450 nm by oxidizing coumarin with the H₂O₂/Fe(II) system to form a blue emitting fluorophore. These decrease/increase responses give a ratiometric signal. The ratio of the fluorescences at the two peaks are linearly related to the concentration of H₂O₂ in the range from 0.05 to 10 μM, with a 7.7 nM limit of detection. The detection scheme was further coupled to the urate oxidase catalyzed oxidation of uric acid which proceeds under the formation of H₂O₂. This method provides an simple and effective means for the construction of ratiometric fluorometric (enzymatic) assays that involve the detection of H₂O₂. Graphical abstract Under catalysis by ferrous ion, hydrogen peroxide quenches the luminescence of gold nanoclusters (AuNCs) and oxidizes coumarin into a fluorescent derivative, which rendered fluorescence ON and OFF at two distinct wavelengths for ratiometric measurements.

A bimetallic nanoparticle/graphene oxide/thionine composite-modified glassy carbon electrode used as a facile ratiometric electrochemical sensor for sensitive uric acid determination

A novel and facile ratiometric electrochemical sensor was developed for sensitive determination of uric acid.

An efficient electrode for simultaneous determination of guanine and adenine using nano-sized lead telluride with graphene

Herein, lead telluride (PbTe) nanocrystals were chemically synthesized at room temperature via reduction of homogeneous mixtures of tartrate complexes of Pb²⁺ and Te⁴⁺ with sodium borohydride.