The design and engineering strategies of metal tellurides for advanced metal-ion batteries

Owning various crystal structures and high theoretical capacity,metal tellurides are emerging as promising electrode materials for high-performance metal-ion batteries(MBs).Since metal telluride-based MBs are quite new,fundamental issues raise regarding the energy storage mechanism and other aspects affecting electrochemical performance.Severe volume expansion,low intrinsic conductivity and slow ion diffusion kinetics jeopardize the performance of metal tellurides,so that rational design and engineering are crucial to circumvent these disadvantages.Herein,this review provides an in-depth discussion of recent investigations and progresses of metal tellurides,beginning with a critical discussion on the energy storage mechanisms of metal tellurides in various MBs.In the following,recent design and engineering strategies of metal tellurides,including morphology engineering,compositing,defect engineering and heterostructure construction,for high-performance MBs are summarized.The primary focus is to present a comprehensive understanding of the structural evolution based on the mechanism and corresponding effects of dimension control,composition,electron configuration and structural complexity on the electrochemical performance.In closing,outlooks and prospects for future development of metal tellurides are proposed.This work also highlights the promising directions of design and engineering strategies of metal tellurides with high performance and low cost.

A monolithic integrated medium wave Mercury Cadmium Telluride polarimetric focal plane array

A medium wave(MW)640×512(25μm)Mercury Cadmium Telluride(HgCdTe)polarimetric focal plane array(FPA)was demonstrated.The micro-polarizer array(MPA)has been carefully designed in terms of line grating structure optimization and crosstalk suppression.A monolithic fabrication process with low damage was explored,which was verified to be compatible well with HgCdTe devices.After monolithic integration of MPA,NETD<9.5 mK was still maintained.Furthermore,to figure out the underlying mechanism that dominat⁃ed the extinction ratio(ER),specialized MPA layouts were designed,and the crosstalk was experimentally vali⁃dated as the major source that impacted ER.By expanding opaque regions at pixel edges to 4μm,crosstalk rates from adjacent pixels could be effectively reduced to approximately 2%,and promising ERs ranging from 17.32 to 27.41 were implemented.

First-Principles Study of the New Layered Ternary Metal Telluride,Eu_(2)InTe_(5)

In this study,we performed first-principles calculations using the VASP(Vienna Ab initio Simulation)software package to investigate the crystal structure,electronic structure,and optical properties of a new layered ternary metal chalcogenide,Eu_(2)InTe_(5).Our results show that Eu_(2)InTe_(5) is a non-zero-gap metal with a layered structure characterized by strong intra-layer atomic bonding and weak inter-layer interaction,which suggests its potential application as a nanomaterial.We also studied the optical properties,including the absorption coefficient,imaginary and real parts of the complex dielectric constant,and found that Eu_(2)InTe_(5) exhibits strong photoresponse characteristics at the junction of ultraviolet and visible light as well as blue-green light,with peaks at wavelengths of 389 nm and 477 nm.This suggests that it could be used in the development of UV(ultraviolet)detectors and other optoelectronic devices.Furthermore,due to its strong absorption,low loss,and low reflectivity,Eu_(2)InTe_(5) has the potential to be used as a promising photovoltaic absorption layer in solar cells.

Novel Synthesis of Benzotriazol-1-yl Methyl Selenides and Tellurides

Benzotriazol-1-yl methyl selenides and tellurides 4a-h can be simply synthesized by the reaction of 2a-b with 3 in good yields.

KOH-assisted aqueous synthesis of bimetallic metal-organic frameworks and their derived selenide composites for efficient lithium storage

To solve low efficiency,environmental pollution,and toxicity for synthesizing zeolitic imidazolate frameworks(ZIFs)in organic solvents,a KOH-assisted aqueous strategy is proposed to synthesize bimetallic ZIFs polyhedrons,which are used as precursors to prepare bimetallic selenide and N-doped carbon(NC)composites.Among them,Fe–Co–Se/NC retains the three-dimensional(3D)polyhedrons with mesoporous structure,and Fe–Co–Se nanoparticles are uniform in size and evenly distributed.When assessed as anode material for lithium-ion batteries,Fe–Co–Se/NC achieves an excellent initial specific capacity of 1165.9 m Ah·g^(-1)at 1.0 A·g^(-1),and the reversible capacity of Fe–Co–Se/NC anode is 1247.4 m Ah·g^(-1)after 550 cycles.It is attributed to that the uniform composite of bimetallic selenides and N-doped carbon can effectively tune redox active sites,the stable 3D structure of Fe–Co–Se/NCs guarantees the structural stability and wettability of the electrolyte,and the uniform distribution of Fe–Co–S nanoparticles in size esuppresses the volume expansion and accelerates the electrochemical reaction kinetics.

Novel ternary metals-based telluride electrocatalyst with synergistic effects of high valence non-3d metal and oxophilic Te for pH-universal hydrogen evolution reaction

Electrocatalyst designs based on oxophilic foreign atoms are considered a promising approach for developing efficient pH-universal hydrogen evolution reaction(HER)electrocatalysts by overcoming the sluggish alkaline HER kinetics.Here,we design ternary transition metals-based nickel telluride(Mo WNi Te)catalysts consisting of high valence non-3d Mo and W metals and oxophilic Te as a first demonstration of non-precious heterogeneous electrocatalysts following the bifunctional mechanism.The Mo WNi Te showed excellent HER catalytic performance with overpotentials of 72,125,and 182 mV to reach the current densities of 10,100,and 1000 mA cm^(-2),respectively,and the corresponding Tafel slope of 47,52,and 58 mV dec-1in alkaline media,which is much superior to commercial Pt/C.Additionally,the HER performance of Mo WNi Te is well maintained up to 3000 h at the current density of 100 mA cm^(-2).It is further demonstrated that the Mo WNi Te exhibits remarkable HER activities with an overpotential of 45 mV(31 mV)and Tafel slope of 60 mV dec-1(34 mV dec-1)at 10 mA cm^(-2)in neutral(acid)media.The superior HER performance of Mo WNi Te is attributed to the electronic structure modulation,inducing highly active low valence states by the incorporation of high valence non-3d transition metals.It is also attributed to the oxophilic effect of Te,accelerating water dissociation kinetics through a bifunctional catalytic mechanism in alkaline media.Density functional theory calculations further reveal that such synergistic effects lead to reduced free energy for an efficient water dissociation process,resulting in remarkable HER catalytic performances within universal pH environments.

Built‑In Electric Field‑Driven Ultrahigh‑Rate K‑Ion Storage via Heterostructure Engineering of Dual Tellurides Integrated with Ti_(3)C_(2)T_(x)MXene

Exploiting high-rate anode materials with fast K+diffusion is intriguing for the development of advanced potassium-ion batteries(KIBs)but remains unrealized.Here,heterostructure engineering is proposed to construct the dual transition metal tellurides(CoTe_(2)/ZnTe),which are anchored onto two-dimensional(2D)Ti_(3)C_(2)T_(x)MXene nanosheets.Various theoretical modeling and experimental findings reveal that heterostructure engineering can regulate the electronic structures of CoTe_(2)/ZnTe interfaces,improving K+diffusion and adsorption.In addition,the different work functions between CoTe_(2)/ZnTe induce a robust built-in electric field at the CoTe_(2)/ZnTe interface,providing a strong driving force to facilitate charge transport.Moreover,the conductive and elastic Ti_(3)C_(2)T_(x)can effectively promote electrode conductivity and alleviate the volume change of CoTe_(2)/ZnTe heterostructures upon cycling.Owing to these merits,the resulting CoTe_(2)/ZnTe/Ti_(3)C_(2)T_(x)(CZT)exhibit excellent rate capability(137.0 mAh g^(-1)at 10 A g^(-1))and cycling stability(175.3 mAh g^(-1)after 4000 cycles at 3.0 A g^(-1),with a high capacity retention of 89.4%).More impressively,the CZT-based full cells demonstrate high energy density(220.2 Wh kg^(-1))and power density(837.2 W kg^(-1)).This work provides a general and effective strategy by integrating heterostructure engineering and 2D material nanocompositing for designing advanced high-rate anode materials for next-generation KIBs.

Efficient hydrogen peroxide production enabled by exploring layered metal telluride as two electron oxygen reduction reaction electrocatalyst

It is of great interest to develop the novel transition metal-based electrocatalysts with high selectivity and activity for two electron oxygen reduction reaction(2e^(-) ORR).Herein,the nickel ditelluride(NiTe_(2)) with layered structure was explored as the 2e^(-) ORR electrocatalyst,which not only showed the highest 2e^(-) selectivity more than 97%,but also delivered a slight activity decay after 5000 cycles in alkaline media.Moreover,when NiTe_(2) was assembled as the electrocatalyst in H-type electrolyzer,the on-site yield of H_(2)O_(2) could reach up to 672 mmol h^(-1)g^(-1) under 0.45 V vs.RHE.Further in situ Raman spectra,theoretical calculation and post microstructural analysis synergistically unveiled that such a good 2e^(-) ORR performance could be credited to the intrinsic layered crystal structure,the high compositional stability,as well as the electron modulation on the active site Ni atoms by neighboring Te atoms,leading to the exposure of active sites as well as the optimized adsorption free energy of Ni to –OOH.More inspiringly,such telluride electrocatalyst has also been demonstrated to exhibit high activity and selectivity towards 2e^(-) ORR in neutral media.

Effect of thickness of antimony selenide film on its photoelectric properties and microstructure

Antimony selenide(Sb2Se3) films are widely used in phase change memory and solar cells due to their stable switching effect and excellent photovoltaic properties. These properties of the films are affected by the film thickness. A method combining the advantages of Levenberg–Marquardt method and spectral fitting method(LM–SFM) is presented to study the dependence of refractive index(RI), absorption coefficient, optical band gap, Wemple–Di Domenico parameters, dielectric constant and optical electronegativity of the Sb2Se3films on their thickness. The results show that the RI and absorption coefficient of the Sb2Se3films increase with the increase of film thickness, while the optical band gap decreases with the increase of film thickness. Finally, the reasons why the optical and electrical properties of the film change with its thickness are explained by x-ray diffractometer(XRD), energy dispersive x-ray spectrometer(EDS), Mott–Davis state density model and Raman microstructure analysis.

Phase transition and high temperature thermoelectric properties of copper selenide Cu_(2-x) Se (0 ≤ x ≤ 0.25)

With good electrical properties and an inherently complex crystal structure, Cu2-xSe is a potential ＂phonon glass electron crystal＂ thermoelectric material that has previously not attracted much interest. In this study, Cu2-xSe （0 ≤ x ≤0.25） compounds were synthesized by a melting-quenching method, and then sintered by spark plasma sintering to obtain bulk material. The effect of Cu content on the phase transition and thermoelectric properties of Cu2-xSe were investigated in the temperature range of 300 K-750 K. The results of X-ray diffraction at room temperature show that Cu2-xSe compounds possess a cubic structure with a space group of Fm3m （#225） when 0.15 〈 x ≤ 0.25, whereas they adopt a composite of monoclinic and cubic phases when 0 ≤x ≤ 0.15. The thermoelectric property measurements show that with increasing Cu content, the electrical conductivity decreases, the Seebeck coefficient increases and the thermal conductivity decreases. Due to the relatively good power factor and low thermal conductivity, the nearly stoichiometric Cu2Se compound achieves the highest ZT of 0.38 at 750 K. It is expected that the thermoelectric performance can be further optimized by doping appropriate elements and/or via a nanostructuring approach.

Nitrogen-Doped Carbon-Encased Bimetallic Selenide for High-Performance Water Electrolysis

Demand of highly efficient earth-abundant transition metal-based electrocatalysts to replace noble metal materials for boosting oxygen evolution reaction(OER)is rapidly growing.Herein,an electrochemically exfoliated graphite(EG)foil supported bimetallic selenide encased in N-doped carbon(EG/(Co,Ni)Se2-NC)hybrid is developed and synthesized by a vapor-phase hydrothermal strategy and subsequent selenization process.The as-prepared EG/(Co,Ni)Se2-NC hybrid exhibits a core-shell structure where the particle diameter of(Co,Ni)Se2 core is about 70 nm and the thickness of N-doped carbon shell is approximately 5 nm.Benefitting from the synergistic effects between the combination of highly active Co species and improved electron transfer from Ni species,and N-doped carbon,the EG/(Co,Ni)Se2-NC hybrid shows remarkable electrocatalytic activity toward OER with a comparatively low overpotential of 258 mV at an current density of 10 mA cm?2 and a small Tafel slope of 73.3 mV dec?1.The excellent OER catalysis performance of EG/(Co,Ni)Se2-NC hybrid is much better than that of commercial Ir/C(343 mV at 10 mA cm?2 and 98.1 mV dec?1),and even almost the best among all previously reported binary CoNi selenide-based OER electrocatalysts.Furthermore,in situ electrochemical Raman spectroscopy combined with ex situ X-ray photoelectron spectroscopy analysis indicates that the superb OER catalysis activity can be attributed to the highly active Co-OOH species and modified electron transfer process from Ni element.

MOF-derived molybdenum selenide on Ti_(3)C_(2)T_(x) with superior capacitive performance for lithium-ion capacitors

Two-dimensional Ti_(3)C_(2)T_(x) exhibits outstanding rate property and cycle performance in lithium-ion capacitors(LICs)due to its unique layered structure,excellent electronic conductivity,and high specific surface area.However,like graphene,Ti_(3)C_(2)T_(x) restacks during electrochemical cycling due to hydrogen bonding or van der Waals forces,leading to a decrease in the specific surface area and an increase in the diffusion distance of electrolyte ions between the interlayer of the material.Here,a transition metal selenide MoSe_(2) with a special three-stacked atomic layered structure,derived from metal-organic framework(MOF),is introduced into the Ti_(3)C_(2)T_(x) structure through a solvo-thermal method.The synergic effects of rapid Li+diffusion and pillaring effect from the MoSe_(2) and excellent conductivity from the Ti_(3)C_(2)T_(x) sheets endow the material with excellent electrochemical reaction kinetics and capacity.The composite Ti_(3)C_(2)T_(x)@MoSe_(2) material exhibits a high capacity over 300 mAh·g^(-1) at 150 mA·g^(-1) and excellent rate property with a specific capacity of 150 mAh·g^(-1) at 1500 mA·g^(-1).Addition-ally,the material shows a superior capacitive contribution of 86.0%at 2.0 mV·s^(-1) due to the fast electrochemical reactions.A Ti_(3)C_(2)T_(x)@MoSe_(2)//AC LIC device is also fabricated and exhibits stable cycle performance.

Development of antimony sulfide–selenide Sb2(S,Se)3-based solar cells

Antimony sulfide–selenide Sb2（S,Se）3,including Sb2S3and Sb2Se3,can be regarded as binary metal chalcogenides semiconductors since Sb2S3and Sb2Se3are isomorphous.They possess abundant elemental storage,nontoxicity,good stability with regard to moisture at elevated temperatures and suitable physical parameters for light absorption materials in solar cells.To date,quite a few attempts have been conducted in the materials synthesis,photovoltaic property investigation and device fabrication.Benefiting from previous investigation in thin film solar cells and new generation nanostructured solar cells,this class of materials has been applied in either sensitized-architecture or planar heterojunction solar cells.Decent power conversion efficiencies from 5%to 7.5%have been achieved.Apparently,further improvement on the efficiency is required for future practical applications.To give an overview of this research field,this paper displays some typical researches regarding the methodologies toward the antimony sulfide–selenide synthesis,development of interfacial materials and device fabrications,during which we highlight some critical findings that promote the efficiency enhancement.Finally,this paper proposes some outstanding issue regarding fundamental understanding of the materials,some viewpoints for the efficiency improvement and their future challenges in solar cell applications.

Stereoselective Synthesis of δd-Selanyl Allylic Alcohols by Hydrozirconation of Propargyl Selenides

Hydrozirconation of propargyl selenides afford (E)-3-selanyl vinylzirconocenes chlorides 2. Intermediates 2 reacted with aldehydes to obtain d-selanyl allylic alcohols.

A Convenient Synthesis of Diacyl Selenides by Selenium Transfer Reaction of Primary Selenoamides

As a selenium transfer reagent, arylselenoamides react with acyl chlorides in chloroform to give diacyl selenides conveniently in good yield.

The Synthesis of Dialdehyde from Sodium Hydrogen Telluride with 1,1',3,3'-Tetramethyl-2,2'-bis-benzimidazolium Salt

The reaction of bis-benzimidazolium salts with sodium hydrogen telluride is reported, and a new synthetic method for dialdehydes is provided.

A Superaerophobic Bimetallic Selenides Heterostructure for Efficient Industrial-Level Oxygen Evolution at Ultra-High Current Densities

Cost-effective and stable electrocatalysts with ultra-high current densities for electrochemical oxygen evolution reaction(OER)are critical to the energy crisis and environmental pollution.Herein,we report a superaerophobic three dimensional(3D)heterostructured nanowrinkles of bimetallic selenides consisting of crystalline NiSe2 and NiFe2Se4 grown on NiFe alloy(NiSe2/NiFe2Se4@NiFe)prepared by a thermal selenization procedure.In this unique 3D heterostructure,numerous nanowrinkles of NiSe2/NiFe2Se4 hybrid with a thickness of ~100 nm are grown on NiFe alloy in a uniform manner.Profiting by the large active surface area and high electronic conductivity,the superaerophobic NiSe2/NiFe2Se4@NiFe heterostructure exhibits excellent electrocatalytic activity and durability towards OER in alkaline media,outputting the low potentials of 1.53 and 1.54 V to achieve ultra-high current densities of 500 and 1000 mA cm^−2,respectively,which is among the most active Ni/Fe-based selenides,and even superior to the benchmark Ir/C catalyst.The in-situ derived FeOOH and NiOOH species from NiSe2/NiFe2Se4@NiFe are deemed to be efficient active sites for OER.

Carbon-Coated Three-Dimensional MXene/Iron Selenide Ball with Core–Shell Structure for High-Performance Potassium-Ion Batteries

Two-dimensional(2D)MXenes are promising as electrode materials for energy storage,owing to their high electronic conductivity and low diffusion barrier.Unfortunately,similar to most 2D materials,MXene nanosheets easily restack during the electrode preparation,which degrades the electrochemical performance of MXene-based materials.A novel synthetic strategy is proposed for converting MXene into restacking-inhibited three-dimensional(3D)balls coated with iron selenides and carbon.This strategy involves the preparation of Fe_(2)O_(3)@carbon/MXene microspheres via a facile ultrasonic spray pyrolysis and subsequent selenization process.Such 3D structuring effectively prevents interlayer restacking,increases the surface area,and accelerates ion transport,while maintaining the attractive properties of MXene.Furthermore,combining iron selenides and carbon with 3D MXene balls offers many more sites for ion storage and enhances the structural robustness of the composite balls.The resultant 3D structured microspheres exhibit a high reversible capacity of 410 mAh g^(−1) after 200 cycles at 0.1 A g^(−1) in potassium-ion batteries,corresponding to the capacity retention of 97% as calculated based on 100 cycles.Even at a high current density of 5.0 A g^(−1),the composite exhibits a discharge capacity of 169 mAh g^(−1).

Bismuth Mediated Organic Reaction: A Convenient Method for the Synthesis of Allylic (Benzylic) Selenides and α-Organylselenocarbonyl Compounds in Aqueous Media

In the presence of BiCl3/Al or BiCl3/Fe, in THF-H2O, allylic (benzylic) bromides or α-bromoketones react with diorganyl diselenides to give allylic (benzylic) selenides orα-organylselenocarbonyl compounds respectively in moderate to good yields.

In Situ Monitoring the Potassium‑Ion Storage Enhancement in Iron Selenide with Ether‑Based Electrolyte

As one of the promising anode materials,iron selenide has received much attention for potassium-ion batteries(KIBs).Nevertheless,volume expansion and sluggish kinetics of iron selenide result in the poor reversibility and stability during potassiation–depotassiation process.In this work,we develop iron selenide composite matching ether-based electrolyte for KIBs,which presents a reversible specific capacity of 356 mAh g^(−1) at 200 mA g^(−1) after 75 cycles.According to the measurement of mechanical properties,it is found that iron selenide composite also exhibits robust and elastic solid electrolyte interphase layer in ether-based electrolyte,contributing to the improvement in reversibility and stability for KIBs.To further investigate the electrochemical enhancement mechanism of ether-based electrolyte in KIBs,we also utilize in situ visualization technique to monitor the potassiation–depotassiation process.For comparison,iron selenide composite matching carbonate-based electrolyte presents vast morphology change during potassiation–depotassiation process.When changing to ether-based electrolyte,a few minor morphology changes can be observed.This phenomenon indicates an occurrence of homogeneous electrochemical reaction in ether-based electrolyte,which results in a stable performance for potassium-ion(K-ion)storage.We believe that our work will provide a new perspective to visually monitor the potassium-ion storage process and guide the improvement in electrode material performance.