The introduction of two-dimensional(2D)perovskite layers on top of three-dimensional(3D)perovskite films enhances the performance and stability of perovskite solar cells(PSCs).However,the electronic effect of the spac...The introduction of two-dimensional(2D)perovskite layers on top of three-dimensional(3D)perovskite films enhances the performance and stability of perovskite solar cells(PSCs).However,the electronic effect of the spacer cation and the quality of the 2D capping layer are critical factors in achieving the required results.In this study,we compared two fluorinated salts:4-(trifluoromethyl)benzamidine hydrochloride(4TF-BA·HCl)and 4-fluorobenzamidine hydrochloride(4F-BA·HCl)to engineer the 3D/2D perovskite films.Surprisingly,4F-BA formed a high-performance 3D/2D heterojunction,while4TF-BA produced an amorphous layer on the perovskite films.Our findings indicate that the balanced intramolecular charge polarization,which leads to effective hydrogen bonding,is more favorable in 4F-BA than in 4TF-BA,promoting the formation of a crystalline 2D perovskite.Nevertheless,4TF-BA managed to improve efficiency to 24%,surpassing the control device,primarily due to the natural passivation capabilities of benzamidine.Interestingly,the devices based on 4F-BA demonstrated an efficiency exceeding 25%with greater longevity under various storage conditions compared to 4TF-BA-based and the control devices.展开更多
Establishing the structure-property relationship in amorphous materials has been a long-term grand challenge due to the lack of a unified description of the degree of disorder.In this work,we develop SPRamNet,a neural...Establishing the structure-property relationship in amorphous materials has been a long-term grand challenge due to the lack of a unified description of the degree of disorder.In this work,we develop SPRamNet,a neural network based machine-learning pipeline that effectively predicts structure-property relationship of amorphous material via global descriptors.Applying SPRamNet on the recently discovered amorphous monolayer carbon,we successfully predict the thermal and electronic properties.More importantly,we reveal that a short range of pair correlation function can readily encode sufficiently rich information of the structure of amorphous material.Utilizing powerful machine learning architectures,the encoded information can be decoded to reconstruct macroscopic properties involving many-body and long-range interactions.Establishing this hidden relationship offers a unified description of the degree of disorder and eliminates the heavy burden of measuring atomic structure,opening a new avenue in studying amorphous materials.展开更多
In general,the rapid growth of α-Fe clusters is a challenge in high Fe-content Fe-based amorphous alloys,negatively affecting their physical properties.Herein,we introduce an efficient and rapid post-treatment techni...In general,the rapid growth of α-Fe clusters is a challenge in high Fe-content Fe-based amorphous alloys,negatively affecting their physical properties.Herein,we introduce an efficient and rapid post-treatment technique known as ultrasonic vibration rapid processing(UVRP),which enables the formation of high-density strong magnetic α-Fe clusters,thereby enhancing the soft magnetic properties of Fe_(78)Si(13)B_(9) amorphous alloy ribbon.展开更多
Ruthenium dioxide(RuO_(2))is one of the most promising acidic oxygen evolution reaction(OER)catalysts to replace the expensive and prevalent iridium(Ir)-based materials.However,the lattice oxygen oxidation induced Ru ...Ruthenium dioxide(RuO_(2))is one of the most promising acidic oxygen evolution reaction(OER)catalysts to replace the expensive and prevalent iridium(Ir)-based materials.However,the lattice oxygen oxidation induced Ru dissolution during OER compromises the activity and stability.Amorphous materials have been identified as a viable strategy to promote the stability of RuO_(2)in acidic OER applications.This study reported a nanoporous amorphous-rich RuMnO_(x)(A-RuMnO_(x))aerogel for efficient and stable acidic OER.Compared with highly crystalline RuMnO_(x),the weakened Ru–O covalency of A-RuMnO_(x)by forming amorphous structure is favorable to inhibiting the oxidation of lattice oxygen.Meanwhile,this also optimizes the electronic structure of Ru sites from overoxidation and reduces the reaction energy barrier of the rate-determining step.As a result,A-RuMnO_(x)aerogel exhibits an ultra-low overpotential of 145 mV at 10 mA cm^(-2)and durability exceeding 100 h,as well as high mass activity up to 153 mA mg^(-1)_(Ru)at 1.5 V vs.reversible hydrogen electrode(RHE).This work provides valuable guidance for preparing highly active and stable Ru-based catalysts for acidic OER.展开更多
Lithium-ion batteries with LiCoO_(2)(LCO)cathodes are widely used in various electronic devices,resulting in a large amount of spent LCO(SLCO).Therefore,there is an urgent need for an efficient technique for recycling...Lithium-ion batteries with LiCoO_(2)(LCO)cathodes are widely used in various electronic devices,resulting in a large amount of spent LCO(SLCO).Therefore,there is an urgent need for an efficient technique for recycling SLCO.However,due to the presence of cobalt oxide with a spinel phase on the surface of highly-degraded LCO,the strong electrostatic repulsion from the transition metal octahedron poses a high Li replenishment barrier,making the regeneration of highly-degraded LCO a challenge.Herein,we propose a structural transformation strategy for reconstructing Li replenishment channels to aid the direct regeneration of highly-degraded LCO.In this approach,ball milling is employed to disrupt the inherent structure of highly-degraded LCO,thereby releasing the internal stress and converting the surface spinel phase into a homogeneous amorphous structure,which promotes Li insertion and regeneration.The regenerated LCO(RLCO)exhibits an outstanding discharge capacity of 179.10 mAh·g^(−1) in the voltage range of 3.0–4.5 V at 0.5 C.The proposed strategy is an effective regeneration approach for highly-degraded LCO,thereby facilitating the efficient recycling of spent lithium-ion battery cathode materials.展开更多
A suction casting experiment was conducted on Zr_(55)Cu_(30)Al_(10)Ni_(5)(at%)amorphous alloy.Using ProCAST software,numerical simulations were performed to analyze the filling and solidification processes.The velocit...A suction casting experiment was conducted on Zr_(55)Cu_(30)Al_(10)Ni_(5)(at%)amorphous alloy.Using ProCAST software,numerical simulations were performed to analyze the filling and solidification processes.The velocity field during the filling process and the temperature field during the solidification process of the alloy melt under different process parameters were obtained.Based on the simulation results,a Zr-based amorphous alloy micro-gear was prepared via casting.The results indicate that increasing the suction casting temperature enhances the fluidity of alloy melt but induces unstable flow rate during filling,which is detrimental to complete filling.Zr-based amorphous micro-gears with a module of 0.6 mm,a tooth top diameter of 8 mm,and 10 teeth were prepared through the suction casting.X-ray diffraction and differential scanning calorimetry analyses confirm that the fabricated micro-gear exhibits characteristic amorphous structural features,demonstrating well-defined geometrical contours and satisfactory forming completeness.展开更多
[Background and purposes]Proton exchange membrane fuel cells(PEMFCs),which convert hydrogen energy directly into electrical energy and water,have received overwhelming attention,owing to their potential to significant...[Background and purposes]Proton exchange membrane fuel cells(PEMFCs),which convert hydrogen energy directly into electrical energy and water,have received overwhelming attention,owing to their potential to significantly reduce energy consumption,pollution emissions and reliance on fossil fuels.Bipolar plates are the major part and key component of PEMFCs stack,which provide mechanical strength,collect and conduct current segregate oxidants and reduce agents.They contribute 70-80%weight and 20-30%cost of a whole stack,while significantly affecting the power density.There are three types plates,including metal bipolar plate,graphite bipolar plate and composite bipolar plate.Stainless steel bipolar plates,as one of metal bipolar plate,exhibit promising manufacturability,competitive cost and durability among various metal materials.However,stainless steel would be corroded in the harsh acid(pH 2-5)and humid PEMFCs environment,whereas the leached ions will contaminate the membrane.In addition,the passivated film formed on the surface will increase the interfacial contact resistance(ICR).In order to improve the corrosion resistance and electrical conductivity of steel bipolar plates,surface coatings are essential.Metal nitride coatings,metal carbide coatings,polymer coatings and carbon-based coatings have been introduced in recent years.Carbon-based coatings,mainly including a-C(amorphous Carbon),Ta-C(Tetrahedral amorphous carbon)and DLC(diamond-like carbon),have attracted considerable attention from both academia and industry,owing to their superior performance,such as chemical inertness,mechanical hardness and electrical conductivity.However,Ta-C films as protective coating of PEMFCs have been rarely reported,due to the difficulty in production for industrial application.In this paper,multi-layer Ta-C composite films were produced by using customized industrial-scale vacuum equipment to address those issues.[Methods]Multiple layered Ta-C coatings were prepared by using PIS624 equipment,which assembled filtered cathodic arc evaporation,ion beam and magnetron sputtering into one equipment,while SS304 and silicon specimens were used as substrate for testing and analysis.Adhesion layer and intermediate layer were deposited by using magnetron sputtering at deposition temperature of 150℃and pressure of 3×10^(−1) Pa,while the sputtering current was set to be 5 A and bias power to be 300 V.The Ta-C layer was coated at arc current of 80-100 A,bias voltage of 1500 V and gas flow of 75 sccm.A scanning electron microscope(CIQTEK SEM3200)was used to characterize surface morphology,coating structure and cross-section profile of the coatings.Raman spectrometer(LabRam HR Evolution,HORIBA JOBIN YVON)was used to identify the bonding valence states.Electrochemical tests were performed by using an electrochemical work station(CHI760,Shanghai Chenhua Instrument Co.,Ltd.),with the traditional three electrode system,where saturated Ag/AgCl and platinum mesh were used as the reference electrode and counter electrode,respectively.All samples were mounted in plastic tube and sealed with epoxy resin,with an exposure area of 2.25 cm^(2),serving as the working electrode.Electrochemical measurements were carried out in simulated PEMFCs cathode environment in 0.5 mol·L^(−1) H_(2)SO_(4)+5 ppm F−solution,at operating temperature of 70℃.As the cathode environment was harsher than the anode environment,all the samples are stabilized at the open-circuit potential(OCP)for approximately 30 min before the EIS measurements.ICR between bipolar plates and GDL was a key parameter affecting performance of the PEMFCs stack.The test sample sandwiched between 2 pieces of carbon paper(simulate gas diffusion layer,GDL)was placed between 2 gold-plated copper electrodes at a compaction pressure of 1.4 MPa,which was considered to be the conventional compaction pressure in the PEMFCs.Under the same conditions,the resistance of a single carbon paper was measured as well.The ICR was calculated according to the formula ICR=1/2(R2−R1)×S,where S was the contact area between GDL and coated stainless steel BPPs.All data of ICR were measured three times for averaging.[Results]The coatings deposited by filtered cathodic arc technology were compact and smooth,which reduced coating porosity and favorable to corrosion resistance.The coating thickness of adhesion and intermediate layers were 180 nm,while the protective Ta-C coating thickness was about 300 nm,forming multiple coating to provide stronger protection for metal bipolar plates.Cr,Ti,Nb and Ta coatings were selected as adhesion layers for comparison.According to electrochemical test,Ta and Nb coatings have higher corrosion resistance.However,Ta and Nb materials would be costly when they are used for mass production.Relatively,Cr and Ti materials were cost effective.Hence,a comprehensive assessment was indispensable to decide the materials to be selected as adhesion layer.Ta-TiN and Ti-TiN combined adhesion and intermediate layer exhibited stronger corrosion resistance,with the corrosion current to be less than 10^(−6) A·cm^(−2).Ta-C protective coating deposited by using filtered cathodic arc technology indicated displayed higher corrosion resistance,with the average corrosion density to be about 1.26×10^(−7) A·cm^(−2).Ta-C coating also shown larger contact angle,with the highest hydrophobicity,which was one of the important advantages for Ta-C,in terms of corrosion resistance.According to Raman spectroscopy,the I(D)/I(G)=549.8/1126.7=0.487,with the estimated fraction of sp^(3) bonding to be in the range of 5154%.The intermediate layer TiN has higher conductivity than the CrN layer.Considering cost,corrosion performance and ICR result,the Ti-TiN layer combination is recommended for industrial scale application.[Conclusions]Multiple layer coating structure of Ta-C film had stronger corrosion resistance;with more than 50%sp^(3) content,while it also had larger water contact angle and higher corrosion resistance than DLC film.The filtered arcing deposition technology was able to make the film to be more consistent and stable than normal arcing technology in terms of the preparation of Ta-C.The coating displayed corrosion density of 1.26×10^(−7) A·cm^(−2) and ICR of less than 5 mΩ·cm^(2),far beyond technical target of 2025 DOE(US Department of Energy).This indicated that the mass-production scale coating technology for PEMFC bipolar plates is highly possible.展开更多
The hydrazine oxidation reaction(HzOR)has garnered significant attention as a feasible approach to replace sluggish anodic reactions to save energy.Nevertheless,there are still difficulties in developing highly effici...The hydrazine oxidation reaction(HzOR)has garnered significant attention as a feasible approach to replace sluggish anodic reactions to save energy.Nevertheless,there are still difficulties in developing highly efficient catalysts for the HzOR.Herein,we report amorphous ruthenium nanosheets(a-Ru NSs)with a thickness of approximately 9.6 nm.As a superior bifunctional electrocatalyst,a-Ru NSs exhibited enhanced electrocatalytic performance toward both the HzOR and hydrogen evolution reaction(HER),outperforming benchmark Pt/C catalysts,where the a-Ru NSs achieved a work-ing potential of merely-76 mV and a low overpotential of only 17 mV to attain a current density of 10 mA·cm^(-2) for the HzOR and HER,respectively.Furthermore,a-Ru NSs displayed a low cell voltage of 28 mV at 10 mA·cm^(-2) for overall hy-drazine splitting in a two-electrode electrolyzer.In situ Raman spectra revealed that the a-Ru NSs can efficiently promote N‒N bond cleavage,thereby producing more*NH_(2)and accelerating the progress of the reaction.展开更多
Amorphous Ga_(2)O_(3)(a-Ga_(2)O_(3))thin films were prepared on flexible polyimide,rigid quartz glass,and Si substrates via radio frequency magnetron sputtering at room temperature.The effect of oxygen/Ar flow rate ra...Amorphous Ga_(2)O_(3)(a-Ga_(2)O_(3))thin films were prepared on flexible polyimide,rigid quartz glass,and Si substrates via radio frequency magnetron sputtering at room temperature.The effect of oxygen/Ar flow rate ratio on the structure,optical property,surface morphology,and chemical bonding properties of the a-Ga_(2)O_(3) films was investigated.Results show that the average optical transmittance of the a-Ga_(2)O_(3) films is over 80%within the wavelength range of 300-2000 nm.The extracted optical band gap of the a-Ga_(2)O_(3) films is increased from 4.97 eV to 5.13 eV with the increase in O_(2)/Ar flow rate ratio from 0 to 0.25,due to the decrease in concentration of oxygen vacancy defects in the film.Furthermore,the optical refractive index and surface roughness of the a-Ga_(2)O_(3) films are optimized when the O_(2)/Ar flow rate ratio reaches 0.25.X-ray photoelectron spectroscopy analysis also shows that the proportion of oxygen vacancies(VO)and Ga-O chemical bonds in the O 1s peak is gradually decreased with the increase in O_(2)/Ar flow rate ratio from 0 to 0.25,proving that increasing the O_(2)/Ar flow rate ratio during film growth can reduce the concentration of oxygen vacancy defects in a-Ga_(2)O_(3) films.In this case,a-Ga_(2)O_(3) with optimal properties can be obtained.This work provides a research basis for high-performance flexible and rigid deep ultraviolet solar-blind detection devices based on a-Ga_(2)O_(3) films.展开更多
In this work,a series of Ce-Ti composite oxides with different Ti/Ce molar ratios was prepared by coprecipitation method,and investigated for the catalytic degradation of toluene and selective catalytic reduction of N...In this work,a series of Ce-Ti composite oxides with different Ti/Ce molar ratios was prepared by coprecipitation method,and investigated for the catalytic degradation of toluene and selective catalytic reduction of NO.The phase transition process between Ce species and Ti species is limited by modulating the interaction between Ce4+and Ti4+,while a completely amorphous composite is generated with an appropriate molar ratio of Ti/Ce(1.5/1).The catalyst CeTi1.5Oxexhibits the best catalytic performance,where the values of T90and T50for deep degradation of toluene are 297 and 330℃respectively at high weight hours space velocity(WHSV=120000 mL/(g·h)).Compared with CeO_(2),T90and T50decrease by48 and 34℃respectively while declining by 67 and 70℃compared to TiO_(2).For the SCR reaction,CeTi1.5Oxreaches 100%NO conversion at 250℃with WHSV=60000 mL/(g·h),reduced by 50℃compared to pure CeO_(2).The amorphous nanostructure with highly dispersed Ce and Ti species was confirmed by transmission electron microscopy(TEM)and X-ray diffraction(XRD)characterizations.The X-ray photoelectron spectroscopy(XPS)and Raman analyses show that a large number of active Ce-O-Ti species and surface oxygen vacancies are generated due to the strong interaction between Ti^(4+)and Ce^(4+)in CeTi_(1.5)O_(x).Additionally,H_(2)-TPR and O_(2)-TPD further confirm that the interaction promotes the low-temperature reducibility and mobility of surface-active oxygen species.Meanwhile,in-situ DRIFTS study reveals that CeTi1.5Oxwith amorphous nanostructure can dramatically enhance the dissociative and complete oxidation capacity for toluene.展开更多
Carbon nanotubes(CNTs)reinforced copper(CNTs/Cu)is one of the most promising and extensively researched materials for replacing traditional Cu-based materials in high-load and high-current applications,particularly wi...Carbon nanotubes(CNTs)reinforced copper(CNTs/Cu)is one of the most promising and extensively researched materials for replacing traditional Cu-based materials in high-load and high-current applications,particularly within the aerospace industry.Amorphous carbon nanotubes(aCNTs)are a type of carbon nanotubes characterized by the presence of mesopores distributed across their amorphous sidewalls,facilitating connectivity between the hollow core and the external environment.Therefore,we propose utilizing aCNTs as a reinforcing agent for Cu.The mesoporous structure of aCNTs facilitates the interpenetration of Cu into the aCNTs,thereby maintaining the continuity of the matrix properties.Experimental results demonstrate that Cu effectively penetrates the mesoporous sidewalls of aCNTs.Both pure Cu and aCNTs-reinforced Cu exhibit comparable electrical conductivity,while the hardness of the aCNTs/Cu composite is significantly enhanced.Additionally,both the density and porosity of aCNTs/Cu are lower than those of pure Cu,and the introduction of aCNTs helps to reduce the sintering temperature.展开更多
Mg_(x)(Ni_(0.8)La_(0.2))_(100-x),where x=60,70,80,exhibiting a nanocrystalline microstructure,were prepared through the crystallization of amorphous alloys.The investigation encompassed the phase constitution,grain si...Mg_(x)(Ni_(0.8)La_(0.2))_(100-x),where x=60,70,80,exhibiting a nanocrystalline microstructure,were prepared through the crystallization of amorphous alloys.The investigation encompassed the phase constitution,grain size,microstructural stability,and hydrogen storage properties.Crystallization kinetics,along with in-situ high-energy XRD characterization,revealed a concentrated and synchronous crystallization of Mg_(2)Ni and RE-Mg-Ni ternary phases with the increase in La and Ni content.The attributed synchronous crystallization process was found to be a result of the close local affinity of Mg_(2)Ni and RE-Mg-Ni ternary phases,as assessed by the thermodynamic Miedema model.Significant secondary phase pinning effect,arising from the high likelihood of well-matching phase structures between Mg_(2)Ni,LaMg_(2)Ni,and LaMgNi_(4),was validated through both the edge-to-edge matching model prediction and experimental observation.Thefine and homogeneous microstructure was shown to be a consequence of fast crystallization kinetics and the secondary phase pinning effect.Improved activation performance and cycling stability were observed,stemming from grain refinement and excellent microstructural stability.Our study provides insights into mechanism of grain refinement of nanocrystalline microstructure tailored by phase constitution and crystallization kinetics in the amorphous-crystallization route.We also demonstrate the potential of material design guided by phase equilibria and crystallographic predictions to improve nanocrystalline with excellent microstructural stability.展开更多
At present,the most common preparation method of amorphous boron powder is magnesium thermal reduction method,but the amorphous boron powder obtained by this method mostly contains impurities such as magnesium and oxy...At present,the most common preparation method of amorphous boron powder is magnesium thermal reduction method,but the amorphous boron powder obtained by this method mostly contains impurities such as magnesium and oxygen which are difficult to remove,and these impurities will seriously affect the application of amorphous boron powder and need to be strictly removed.In this research,the acid-insoluble impurities were modified through sintering and quenching,while the magnesium impurities were optimized via ultrasonic acid leaching.We observed that the quenching temperature played a crucial role in determining the efficiency of magnesium impurity removal.The results show that the magnesium content in amorphous boron powder can be reduced from 5.67%to 2.40%by quenching the amorphous boron powder at 800°C and using ultrasonic assisted acid leaching.Furthermore,the oxidation reaction of boron is influenced by the powder's particle size and specific surface area,with the effective activation energy being intimately tied to both these factors.Post-quenching and acid leaching,we observed an increase in the specific surface area of the boron powder samples,leading to enhanced activity.In conclusion,our study presents an effective strategy to mitigate magnesium impurities and elevate the performance of amorphous boron powder,offering promising avenues for advancing its utilization across diverse industries.展开更多
Polyanionic materials are considered one of the most promising cathode materials for sodium-ion batteries because of the stable structure framework and high working voltage.However,most polyanionic materials possess l...Polyanionic materials are considered one of the most promising cathode materials for sodium-ion batteries because of the stable structure framework and high working voltage.However,most polyanionic materials possess limited sodium storage sites and have to undergo complex local structure evolution during charge/discharge.Herein,we conducted a systematic investigation into the impact of structural forms of NaVOPO_(4)on the electrochemical properties.Amorphous and crystalline NaVOPO_(4)are synthesized through a controlled reflux reduction method,and the amorphous NaVOPO_(4)(a-NVOP)demonstrates much better electrochemical performance compared to the crystalline counterpart.Specifically,the a-NVOP electrode delivers high reversible capacity(142 mAh g^(-1)at 14.5 mA g^(-1),close to the theoretical capacity of 145 mAh g^(-1)),high energy density(497 Wh kg^(-1)based on cathode material)and remarkable cyclability with capacity retention of 80%after 500 cycles.In situ and ex situ experimental analyses and theoretical calculations reveal that the superior performance is primarily due to the maintaining of the amorphous state during the charge/discharge process to endow high stability and accelerated intercalation/deintercalation of large-sized Na^(+)without lattice constraints.Furthermore,the amorphous cathode materials show promising electrochemical properties in lithium-,potassium-and zinc-ion batteries,highlighting their broad adaptability and potential across various battery systems.展开更多
Recent advancements in electrocatalysis have highlighted the exceptional application value of amorphous electrocatalysts. Withtheir unique atomic configurations, these electrocatalysts exhibit superior catalytic perfo...Recent advancements in electrocatalysis have highlighted the exceptional application value of amorphous electrocatalysts. Withtheir unique atomic configurations, these electrocatalysts exhibit superior catalytic performance compared to that of their crystalline coun-terparts. Transition metal(TM) amorphous ribbon-shaped electrocatalysts have recently emerged as a new frontier in the catalysis field.Dealloying is widely considered a fascinating method for enhancing the electrocatalyst performance. In this review, we comprehensivelyexamine the principles of water electrolysis, discuss the prevalent methods for fabricating ribbon-configured electrocatalysts, and providean overview of amorphous alloys. Furthermore, we discuss binary, ternary, and high-entropy amorphous TM-based electrocatalysts,which satisfy the requirements necessary for effective water electrolysis. We also propose strategies to enhance the activity of amorphousTM-based ribbons, including morphology control, defect engineering, composition optimization, and heterostructure creation in differentelectrolytes. Our focus extends to the latest developments in the design of heterogeneous micro/nanostructures, management of prepara-tion techniques, and synthesis of different compositions. Finally, we address the ongoing challenges and provide a perspective on the fu-ture development of broadly applicable, self-supporting TM ribbon-shaped electrocatalysts.展开更多
Four types of resins,P1–P4,are used as binders for FeSiBC amorphous powder,which are then press-molded and heat-treated to fabricate magnetic powder cores(MPCs).By testing the permeability,loss,density,and radial cru...Four types of resins,P1–P4,are used as binders for FeSiBC amorphous powder,which are then press-molded and heat-treated to fabricate magnetic powder cores(MPCs).By testing the permeability,loss,density,and radial crush strength of MPCs,the effect of the binder on the magnetic properties of the cores is investigated and the best resin is found.The results show that the silicone resin P3 exhibits the best thermal stability,retaining 82.1%of its mass after heat treatment at 430°C.This contributes to improving the insulation of MPCs and reducing the eddy current loss,which is 46.06 mW cm^(−3)(150 kHz,20 mT)with the mechanical strength of 11.13 MPa.The bonding of epoxy resin P4 is superior to that of other resins,which significantly improves the powder compactness and makes MPCs density reach 5.67 g cm^(−3),and its permeability is as high as 28.7.The two types of resins have different advantages,and both lead to MPCs with excellent properties.展开更多
The in-depth study of the transport properties of the solid electrolyte interface(SEI)is crucial for the development of ultra-high-rate,and long lifespan sodium-ion batteries(SIBs).However,there remains a lack of theo...The in-depth study of the transport properties of the solid electrolyte interface(SEI)is crucial for the development of ultra-high-rate,and long lifespan sodium-ion batteries(SIBs).However,there remains a lack of theoretical investigation into the transport mechanisms of the main inorganic components of the SEI,namely Na F,Na_(2)O,and Na_(2)CO_(3).To address this research gap,we performed classical molecular dynamics simulations in this work to study the diffusion mechanisms of sodium ions in these inorganic components of the SEI,with special emphasis on the impact of the amorphous SEI environment on the diffusion behavior of sodium ions.The results have shown that amorphous SEI components significantly enhance the diffusion rate of sodium ions at room temperature compared to crystalline components.Within these amorphous SEI components,we reveal that the diffusion coefficients of sodium ions in amorphous Na_(2)O and Na_(2)CO_(3)are more than an order of magnitude higher than that of Na F,suggesting that amorphous Na_(2)O and Na_(2)CO_(3)are more effective in facilitating the Na ion diffusion.Analysis of the local atomic structure indicates that the amorphous local structures are dominant in Na_(2)O and Na_(2)CO_(3)at room temperature,maintaining a disordered amorphous phase.In contrast,amorphous Na F undergoes a spontaneously transformation into an ordered structure,exhibiting crystalline characteristics that restrict the diffusion of sodium ions.In summary,our work provides atomic insights into the impact of local amorphous environments on Na ion diffusion in SEI and suggests that amorphous SEI components play a critical role in improving battery performance.展开更多
In order to develop a generic framework capable of designing novel amorphous alloys with selected target properties,a predictor−corrector inverse design scheme(PCIDS)consisting of a predictor module and a corrector mo...In order to develop a generic framework capable of designing novel amorphous alloys with selected target properties,a predictor−corrector inverse design scheme(PCIDS)consisting of a predictor module and a corrector module was presented.A high-precision forward prediction model based on deep neural networks was developed to implement these two parts.Of utmost importance,domain knowledge-guided inverse design networks(DKIDNs)and regular inverse design networks(RIDNs)were also developed.The forward prediction model possesses a coefficient of determination(R^(2))of 0.990 for the shear modulus and 0.986 for the bulk modulus on the testing set.Furthermore,the DKIDNs model exhibits superior performance compared to the RIDNs model.It is finally demonstrated that PCIDS can efficiently predict amorphous alloy compositions with the required target properties.展开更多
Amorphous transition metal compounds(a-TMC)become one of the most promising pre-catalysts toward oxygen evolution reaction(OER)due to their high-entropy nature and flexible self-reconstruction to highly active derivat...Amorphous transition metal compounds(a-TMC)become one of the most promising pre-catalysts toward oxygen evolution reaction(OER)due to their high-entropy nature and flexible self-reconstruction to highly active derivatives.However,the loosen bonds inside the amorphous structure make it an electronic insulator with unstable structure.Here,monodispersed Ni^(2+)-phytate nanospheres implanted by Fe^(3+)ions(NS_(FeNiPA))were firstly prepared and subsequently transferred into homogeneous high-entropy type Fe-Ni-P-O-C amorphous nanospheres(CNS_(FeNiPO)).It is shown that the CNS_(FeNiPO) presents robust structure and remarkable Fe ions migration during potential-driven activation process,which benefits efficient surface reconstruction and spherical morphology preservation.The CNS_(FeNiPO) with low mass loading of 0.1mg/cm^(2)could deliver small overpotential of 270mV at 10mAcm^(−2)and almost 100%retention of the initial current density after 10h test.The improved electrocatalytic activity is attributed to the boosted electron transfer from Ni sites to O-containing intermediates by introduction of Fe and P atoms.Moreover,rechargeable Zn-air battery with CNS_(FeNiPO)+Pt/C could achieve lower charge potential platform and better cycling performance than that with commercial RuO_(2)+Pt/C.This work provides new insights into the design and understanding of high-entropy amorphous pre-catalysts toward OER.展开更多
The core@shell structure materials with the synergistic effect have been confirmed as promising catalysts for oxygen evolution reaction(OER).However,the conventional catalysts with crystalline phase suffer from defici...The core@shell structure materials with the synergistic effect have been confirmed as promising catalysts for oxygen evolution reaction(OER).However,the conventional catalysts with crystalline phase suffer from deficient active sites,elemental dissolution,and structural collapse during OER catalysis,which results in the limited OER performance.Herein,we introduced the amorphous phase structure by controllable wet-chemical sulfuration strategy,thus to prepare the amorphous/crystalline(a/c)Ag S@Co S core@shell catalysts.Benefitting from the core@shell construction with synergistic interaction,a/c heterophase with well-balanced catalytic activity and stability,favorable sulfides components with positive oxysulfide reconstructed layer formation,the optimized Ag S@CoS-2 catalysts displayed superior OER catalytic behaviors with a low overpotential of 260 m V and Tafel slope of 64.4 m V/dec on the current density of 10 m A/cm^(2),surpassing the counterpart catalysts and commercial RuO_(2)catalysts.Meanwhile,the Ag S@CoS-2 catalysts possessed remarkable OER catalytic stability,as well as the favorable overall water splitting performance.展开更多
基金supported by the National Key Research and Development Programs-Intergovernmental International Cooperation in Science and Technology Innovation Project(Grant No.2022YFE0118400)the Natural Science Foundation of Hunan Province(2023JJ50132)+1 种基金Shenzhen Science and Technology Innovation Committee(Grants Nos.JCYJ20220818100211025,and KCXST20221021111616039)Shenzhen Science and Technology Program(No.20231128110928003)。
文摘The introduction of two-dimensional(2D)perovskite layers on top of three-dimensional(3D)perovskite films enhances the performance and stability of perovskite solar cells(PSCs).However,the electronic effect of the spacer cation and the quality of the 2D capping layer are critical factors in achieving the required results.In this study,we compared two fluorinated salts:4-(trifluoromethyl)benzamidine hydrochloride(4TF-BA·HCl)and 4-fluorobenzamidine hydrochloride(4F-BA·HCl)to engineer the 3D/2D perovskite films.Surprisingly,4F-BA formed a high-performance 3D/2D heterojunction,while4TF-BA produced an amorphous layer on the perovskite films.Our findings indicate that the balanced intramolecular charge polarization,which leads to effective hydrogen bonding,is more favorable in 4F-BA than in 4TF-BA,promoting the formation of a crystalline 2D perovskite.Nevertheless,4TF-BA managed to improve efficiency to 24%,surpassing the control device,primarily due to the natural passivation capabilities of benzamidine.Interestingly,the devices based on 4F-BA demonstrated an efficiency exceeding 25%with greater longevity under various storage conditions compared to 4TF-BA-based and the control devices.
基金supported by the National Key R&D Program of China under Grant No.2021YFA1400500the Strategic Priority Research Program of the Chinese Academy of Sciences under Grant No.XDB33000000+1 种基金the National Natural Science Foundation of China under Grant No.12334003the Beijing Municipal Natural Science Foundation under Grant Nos.JQ22001 and QY23014。
文摘Establishing the structure-property relationship in amorphous materials has been a long-term grand challenge due to the lack of a unified description of the degree of disorder.In this work,we develop SPRamNet,a neural network based machine-learning pipeline that effectively predicts structure-property relationship of amorphous material via global descriptors.Applying SPRamNet on the recently discovered amorphous monolayer carbon,we successfully predict the thermal and electronic properties.More importantly,we reveal that a short range of pair correlation function can readily encode sufficiently rich information of the structure of amorphous material.Utilizing powerful machine learning architectures,the encoded information can be decoded to reconstruct macroscopic properties involving many-body and long-range interactions.Establishing this hidden relationship offers a unified description of the degree of disorder and eliminates the heavy burden of measuring atomic structure,opening a new avenue in studying amorphous materials.
基金supported by the Major Science and Technology Project of Zhongshan City(No.2022AJ004)the Key Basic and Applied Research Program of Guangdong Province(Nos.2019B030302010 and 2022B1515120082)Guangdong Science and Technology Innovation Project(No.2021TX06C111).
文摘In general,the rapid growth of α-Fe clusters is a challenge in high Fe-content Fe-based amorphous alloys,negatively affecting their physical properties.Herein,we introduce an efficient and rapid post-treatment technique known as ultrasonic vibration rapid processing(UVRP),which enables the formation of high-density strong magnetic α-Fe clusters,thereby enhancing the soft magnetic properties of Fe_(78)Si(13)B_(9) amorphous alloy ribbon.
基金financial support from the National Natural Science Foundation of China(22478278,22308246)the Central Government Guides the Local Science and Technology Development Special Fund(YDZJSX20231A015)the Fundamental Research Program of Shanxi Province(202203021212266)。
文摘Ruthenium dioxide(RuO_(2))is one of the most promising acidic oxygen evolution reaction(OER)catalysts to replace the expensive and prevalent iridium(Ir)-based materials.However,the lattice oxygen oxidation induced Ru dissolution during OER compromises the activity and stability.Amorphous materials have been identified as a viable strategy to promote the stability of RuO_(2)in acidic OER applications.This study reported a nanoporous amorphous-rich RuMnO_(x)(A-RuMnO_(x))aerogel for efficient and stable acidic OER.Compared with highly crystalline RuMnO_(x),the weakened Ru–O covalency of A-RuMnO_(x)by forming amorphous structure is favorable to inhibiting the oxidation of lattice oxygen.Meanwhile,this also optimizes the electronic structure of Ru sites from overoxidation and reduces the reaction energy barrier of the rate-determining step.As a result,A-RuMnO_(x)aerogel exhibits an ultra-low overpotential of 145 mV at 10 mA cm^(-2)and durability exceeding 100 h,as well as high mass activity up to 153 mA mg^(-1)_(Ru)at 1.5 V vs.reversible hydrogen electrode(RHE).This work provides valuable guidance for preparing highly active and stable Ru-based catalysts for acidic OER.
基金supported by a project of the Tsinghua Shenzhen International Graduate School-Shenzhen Pengrui Young Faculty Program of Shenzhen Pengrui Foundation(Grant No.SZPR2023007)Natural Science Foundation of Sichuan Province(Grant No.2025ZNSFSC0449)Shenzhen Science and Technology Program(Grant No.RCBS20231211090637065).
文摘Lithium-ion batteries with LiCoO_(2)(LCO)cathodes are widely used in various electronic devices,resulting in a large amount of spent LCO(SLCO).Therefore,there is an urgent need for an efficient technique for recycling SLCO.However,due to the presence of cobalt oxide with a spinel phase on the surface of highly-degraded LCO,the strong electrostatic repulsion from the transition metal octahedron poses a high Li replenishment barrier,making the regeneration of highly-degraded LCO a challenge.Herein,we propose a structural transformation strategy for reconstructing Li replenishment channels to aid the direct regeneration of highly-degraded LCO.In this approach,ball milling is employed to disrupt the inherent structure of highly-degraded LCO,thereby releasing the internal stress and converting the surface spinel phase into a homogeneous amorphous structure,which promotes Li insertion and regeneration.The regenerated LCO(RLCO)exhibits an outstanding discharge capacity of 179.10 mAh·g^(−1) in the voltage range of 3.0–4.5 V at 0.5 C.The proposed strategy is an effective regeneration approach for highly-degraded LCO,thereby facilitating the efficient recycling of spent lithium-ion battery cathode materials.
基金National Natural Science Foundation of China(51971103)Key Research and Development Program in Gansu Province(20YF8GA052)。
文摘A suction casting experiment was conducted on Zr_(55)Cu_(30)Al_(10)Ni_(5)(at%)amorphous alloy.Using ProCAST software,numerical simulations were performed to analyze the filling and solidification processes.The velocity field during the filling process and the temperature field during the solidification process of the alloy melt under different process parameters were obtained.Based on the simulation results,a Zr-based amorphous alloy micro-gear was prepared via casting.The results indicate that increasing the suction casting temperature enhances the fluidity of alloy melt but induces unstable flow rate during filling,which is detrimental to complete filling.Zr-based amorphous micro-gears with a module of 0.6 mm,a tooth top diameter of 8 mm,and 10 teeth were prepared through the suction casting.X-ray diffraction and differential scanning calorimetry analyses confirm that the fabricated micro-gear exhibits characteristic amorphous structural features,demonstrating well-defined geometrical contours and satisfactory forming completeness.
基金Major Science and technology projects of Anhui Province (202103a05020003)。
文摘[Background and purposes]Proton exchange membrane fuel cells(PEMFCs),which convert hydrogen energy directly into electrical energy and water,have received overwhelming attention,owing to their potential to significantly reduce energy consumption,pollution emissions and reliance on fossil fuels.Bipolar plates are the major part and key component of PEMFCs stack,which provide mechanical strength,collect and conduct current segregate oxidants and reduce agents.They contribute 70-80%weight and 20-30%cost of a whole stack,while significantly affecting the power density.There are three types plates,including metal bipolar plate,graphite bipolar plate and composite bipolar plate.Stainless steel bipolar plates,as one of metal bipolar plate,exhibit promising manufacturability,competitive cost and durability among various metal materials.However,stainless steel would be corroded in the harsh acid(pH 2-5)and humid PEMFCs environment,whereas the leached ions will contaminate the membrane.In addition,the passivated film formed on the surface will increase the interfacial contact resistance(ICR).In order to improve the corrosion resistance and electrical conductivity of steel bipolar plates,surface coatings are essential.Metal nitride coatings,metal carbide coatings,polymer coatings and carbon-based coatings have been introduced in recent years.Carbon-based coatings,mainly including a-C(amorphous Carbon),Ta-C(Tetrahedral amorphous carbon)and DLC(diamond-like carbon),have attracted considerable attention from both academia and industry,owing to their superior performance,such as chemical inertness,mechanical hardness and electrical conductivity.However,Ta-C films as protective coating of PEMFCs have been rarely reported,due to the difficulty in production for industrial application.In this paper,multi-layer Ta-C composite films were produced by using customized industrial-scale vacuum equipment to address those issues.[Methods]Multiple layered Ta-C coatings were prepared by using PIS624 equipment,which assembled filtered cathodic arc evaporation,ion beam and magnetron sputtering into one equipment,while SS304 and silicon specimens were used as substrate for testing and analysis.Adhesion layer and intermediate layer were deposited by using magnetron sputtering at deposition temperature of 150℃and pressure of 3×10^(−1) Pa,while the sputtering current was set to be 5 A and bias power to be 300 V.The Ta-C layer was coated at arc current of 80-100 A,bias voltage of 1500 V and gas flow of 75 sccm.A scanning electron microscope(CIQTEK SEM3200)was used to characterize surface morphology,coating structure and cross-section profile of the coatings.Raman spectrometer(LabRam HR Evolution,HORIBA JOBIN YVON)was used to identify the bonding valence states.Electrochemical tests were performed by using an electrochemical work station(CHI760,Shanghai Chenhua Instrument Co.,Ltd.),with the traditional three electrode system,where saturated Ag/AgCl and platinum mesh were used as the reference electrode and counter electrode,respectively.All samples were mounted in plastic tube and sealed with epoxy resin,with an exposure area of 2.25 cm^(2),serving as the working electrode.Electrochemical measurements were carried out in simulated PEMFCs cathode environment in 0.5 mol·L^(−1) H_(2)SO_(4)+5 ppm F−solution,at operating temperature of 70℃.As the cathode environment was harsher than the anode environment,all the samples are stabilized at the open-circuit potential(OCP)for approximately 30 min before the EIS measurements.ICR between bipolar plates and GDL was a key parameter affecting performance of the PEMFCs stack.The test sample sandwiched between 2 pieces of carbon paper(simulate gas diffusion layer,GDL)was placed between 2 gold-plated copper electrodes at a compaction pressure of 1.4 MPa,which was considered to be the conventional compaction pressure in the PEMFCs.Under the same conditions,the resistance of a single carbon paper was measured as well.The ICR was calculated according to the formula ICR=1/2(R2−R1)×S,where S was the contact area between GDL and coated stainless steel BPPs.All data of ICR were measured three times for averaging.[Results]The coatings deposited by filtered cathodic arc technology were compact and smooth,which reduced coating porosity and favorable to corrosion resistance.The coating thickness of adhesion and intermediate layers were 180 nm,while the protective Ta-C coating thickness was about 300 nm,forming multiple coating to provide stronger protection for metal bipolar plates.Cr,Ti,Nb and Ta coatings were selected as adhesion layers for comparison.According to electrochemical test,Ta and Nb coatings have higher corrosion resistance.However,Ta and Nb materials would be costly when they are used for mass production.Relatively,Cr and Ti materials were cost effective.Hence,a comprehensive assessment was indispensable to decide the materials to be selected as adhesion layer.Ta-TiN and Ti-TiN combined adhesion and intermediate layer exhibited stronger corrosion resistance,with the corrosion current to be less than 10^(−6) A·cm^(−2).Ta-C protective coating deposited by using filtered cathodic arc technology indicated displayed higher corrosion resistance,with the average corrosion density to be about 1.26×10^(−7) A·cm^(−2).Ta-C coating also shown larger contact angle,with the highest hydrophobicity,which was one of the important advantages for Ta-C,in terms of corrosion resistance.According to Raman spectroscopy,the I(D)/I(G)=549.8/1126.7=0.487,with the estimated fraction of sp^(3) bonding to be in the range of 5154%.The intermediate layer TiN has higher conductivity than the CrN layer.Considering cost,corrosion performance and ICR result,the Ti-TiN layer combination is recommended for industrial scale application.[Conclusions]Multiple layer coating structure of Ta-C film had stronger corrosion resistance;with more than 50%sp^(3) content,while it also had larger water contact angle and higher corrosion resistance than DLC film.The filtered arcing deposition technology was able to make the film to be more consistent and stable than normal arcing technology in terms of the preparation of Ta-C.The coating displayed corrosion density of 1.26×10^(−7) A·cm^(−2) and ICR of less than 5 mΩ·cm^(2),far beyond technical target of 2025 DOE(US Department of Energy).This indicated that the mass-production scale coating technology for PEMFC bipolar plates is highly possible.
基金supported by the National Key R&D Program of China(2018YFA0702001)National Natural Science Foundation of China(22371268,22301287)+3 种基金Fundamental Research Funds for the Central Universities(WK2060000016)Anhui Provincial Natural Science Foundation(2208085J09,2208085QB33)Collaborative Innovation Program of Hefei Science Center,CAS(2022HSC-CIP020)Youth Innovation Promotion Association of the Chinese Academy of Science(2018494)and USTC Tang Scholar.
文摘The hydrazine oxidation reaction(HzOR)has garnered significant attention as a feasible approach to replace sluggish anodic reactions to save energy.Nevertheless,there are still difficulties in developing highly efficient catalysts for the HzOR.Herein,we report amorphous ruthenium nanosheets(a-Ru NSs)with a thickness of approximately 9.6 nm.As a superior bifunctional electrocatalyst,a-Ru NSs exhibited enhanced electrocatalytic performance toward both the HzOR and hydrogen evolution reaction(HER),outperforming benchmark Pt/C catalysts,where the a-Ru NSs achieved a work-ing potential of merely-76 mV and a low overpotential of only 17 mV to attain a current density of 10 mA·cm^(-2) for the HzOR and HER,respectively.Furthermore,a-Ru NSs displayed a low cell voltage of 28 mV at 10 mA·cm^(-2) for overall hy-drazine splitting in a two-electrode electrolyzer.In situ Raman spectra revealed that the a-Ru NSs can efficiently promote N‒N bond cleavage,thereby producing more*NH_(2)and accelerating the progress of the reaction.
基金Research Project of Shenzhen Science and Technology Innovation Committee(JCYJ20180306170801080)。
文摘Amorphous Ga_(2)O_(3)(a-Ga_(2)O_(3))thin films were prepared on flexible polyimide,rigid quartz glass,and Si substrates via radio frequency magnetron sputtering at room temperature.The effect of oxygen/Ar flow rate ratio on the structure,optical property,surface morphology,and chemical bonding properties of the a-Ga_(2)O_(3) films was investigated.Results show that the average optical transmittance of the a-Ga_(2)O_(3) films is over 80%within the wavelength range of 300-2000 nm.The extracted optical band gap of the a-Ga_(2)O_(3) films is increased from 4.97 eV to 5.13 eV with the increase in O_(2)/Ar flow rate ratio from 0 to 0.25,due to the decrease in concentration of oxygen vacancy defects in the film.Furthermore,the optical refractive index and surface roughness of the a-Ga_(2)O_(3) films are optimized when the O_(2)/Ar flow rate ratio reaches 0.25.X-ray photoelectron spectroscopy analysis also shows that the proportion of oxygen vacancies(VO)and Ga-O chemical bonds in the O 1s peak is gradually decreased with the increase in O_(2)/Ar flow rate ratio from 0 to 0.25,proving that increasing the O_(2)/Ar flow rate ratio during film growth can reduce the concentration of oxygen vacancy defects in a-Ga_(2)O_(3) films.In this case,a-Ga_(2)O_(3) with optimal properties can be obtained.This work provides a research basis for high-performance flexible and rigid deep ultraviolet solar-blind detection devices based on a-Ga_(2)O_(3) films.
基金Project supported by the National Natural Science Foundation of China(22072096,22108184)。
文摘In this work,a series of Ce-Ti composite oxides with different Ti/Ce molar ratios was prepared by coprecipitation method,and investigated for the catalytic degradation of toluene and selective catalytic reduction of NO.The phase transition process between Ce species and Ti species is limited by modulating the interaction between Ce4+and Ti4+,while a completely amorphous composite is generated with an appropriate molar ratio of Ti/Ce(1.5/1).The catalyst CeTi1.5Oxexhibits the best catalytic performance,where the values of T90and T50for deep degradation of toluene are 297 and 330℃respectively at high weight hours space velocity(WHSV=120000 mL/(g·h)).Compared with CeO_(2),T90and T50decrease by48 and 34℃respectively while declining by 67 and 70℃compared to TiO_(2).For the SCR reaction,CeTi1.5Oxreaches 100%NO conversion at 250℃with WHSV=60000 mL/(g·h),reduced by 50℃compared to pure CeO_(2).The amorphous nanostructure with highly dispersed Ce and Ti species was confirmed by transmission electron microscopy(TEM)and X-ray diffraction(XRD)characterizations.The X-ray photoelectron spectroscopy(XPS)and Raman analyses show that a large number of active Ce-O-Ti species and surface oxygen vacancies are generated due to the strong interaction between Ti^(4+)and Ce^(4+)in CeTi_(1.5)O_(x).Additionally,H_(2)-TPR and O_(2)-TPD further confirm that the interaction promotes the low-temperature reducibility and mobility of surface-active oxygen species.Meanwhile,in-situ DRIFTS study reveals that CeTi1.5Oxwith amorphous nanostructure can dramatically enhance the dissociative and complete oxidation capacity for toluene.
文摘Carbon nanotubes(CNTs)reinforced copper(CNTs/Cu)is one of the most promising and extensively researched materials for replacing traditional Cu-based materials in high-load and high-current applications,particularly within the aerospace industry.Amorphous carbon nanotubes(aCNTs)are a type of carbon nanotubes characterized by the presence of mesopores distributed across their amorphous sidewalls,facilitating connectivity between the hollow core and the external environment.Therefore,we propose utilizing aCNTs as a reinforcing agent for Cu.The mesoporous structure of aCNTs facilitates the interpenetration of Cu into the aCNTs,thereby maintaining the continuity of the matrix properties.Experimental results demonstrate that Cu effectively penetrates the mesoporous sidewalls of aCNTs.Both pure Cu and aCNTs-reinforced Cu exhibit comparable electrical conductivity,while the hardness of the aCNTs/Cu composite is significantly enhanced.Additionally,both the density and porosity of aCNTs/Cu are lower than those of pure Cu,and the introduction of aCNTs helps to reduce the sintering temperature.
基金supported by National Natural Science Foundation of China(51761034,51961032,51962028 and 52261041)Innovation Foundation of Inner Mongolia University of Science and Technology(2019YQL03)+2 种基金Major Science and Technology Project of Inner Mongolia(2021ZD0029)Program for Young Talents of Science and Technology in Universities of Inner Mongolia Autonomous Region(NJYT23005,NJYT23007)Program for Innovative Research Team in Universities of Inner Mongolia Autonomous Region(NMGIRT2401).
文摘Mg_(x)(Ni_(0.8)La_(0.2))_(100-x),where x=60,70,80,exhibiting a nanocrystalline microstructure,were prepared through the crystallization of amorphous alloys.The investigation encompassed the phase constitution,grain size,microstructural stability,and hydrogen storage properties.Crystallization kinetics,along with in-situ high-energy XRD characterization,revealed a concentrated and synchronous crystallization of Mg_(2)Ni and RE-Mg-Ni ternary phases with the increase in La and Ni content.The attributed synchronous crystallization process was found to be a result of the close local affinity of Mg_(2)Ni and RE-Mg-Ni ternary phases,as assessed by the thermodynamic Miedema model.Significant secondary phase pinning effect,arising from the high likelihood of well-matching phase structures between Mg_(2)Ni,LaMg_(2)Ni,and LaMgNi_(4),was validated through both the edge-to-edge matching model prediction and experimental observation.Thefine and homogeneous microstructure was shown to be a consequence of fast crystallization kinetics and the secondary phase pinning effect.Improved activation performance and cycling stability were observed,stemming from grain refinement and excellent microstructural stability.Our study provides insights into mechanism of grain refinement of nanocrystalline microstructure tailored by phase constitution and crystallization kinetics in the amorphous-crystallization route.We also demonstrate the potential of material design guided by phase equilibria and crystallographic predictions to improve nanocrystalline with excellent microstructural stability.
基金support on this research from the Talent Training Program of Yunnan of China(Grant Nos.202005AC160041 and KKXY202252002)the"Xingdian Talent"Industry Innovation Talent Program in Yunnan Province(Grant No.XDYC-CYCX-2022-0042)。
文摘At present,the most common preparation method of amorphous boron powder is magnesium thermal reduction method,but the amorphous boron powder obtained by this method mostly contains impurities such as magnesium and oxygen which are difficult to remove,and these impurities will seriously affect the application of amorphous boron powder and need to be strictly removed.In this research,the acid-insoluble impurities were modified through sintering and quenching,while the magnesium impurities were optimized via ultrasonic acid leaching.We observed that the quenching temperature played a crucial role in determining the efficiency of magnesium impurity removal.The results show that the magnesium content in amorphous boron powder can be reduced from 5.67%to 2.40%by quenching the amorphous boron powder at 800°C and using ultrasonic assisted acid leaching.Furthermore,the oxidation reaction of boron is influenced by the powder's particle size and specific surface area,with the effective activation energy being intimately tied to both these factors.Post-quenching and acid leaching,we observed an increase in the specific surface area of the boron powder samples,leading to enhanced activity.In conclusion,our study presents an effective strategy to mitigate magnesium impurities and elevate the performance of amorphous boron powder,offering promising avenues for advancing its utilization across diverse industries.
基金financially supported by the National Nature Science Foundation of China(Nos.22209125,22479118,and 22479117)the National Key Research and Development Program of China(No.2021YFB3800300)
文摘Polyanionic materials are considered one of the most promising cathode materials for sodium-ion batteries because of the stable structure framework and high working voltage.However,most polyanionic materials possess limited sodium storage sites and have to undergo complex local structure evolution during charge/discharge.Herein,we conducted a systematic investigation into the impact of structural forms of NaVOPO_(4)on the electrochemical properties.Amorphous and crystalline NaVOPO_(4)are synthesized through a controlled reflux reduction method,and the amorphous NaVOPO_(4)(a-NVOP)demonstrates much better electrochemical performance compared to the crystalline counterpart.Specifically,the a-NVOP electrode delivers high reversible capacity(142 mAh g^(-1)at 14.5 mA g^(-1),close to the theoretical capacity of 145 mAh g^(-1)),high energy density(497 Wh kg^(-1)based on cathode material)and remarkable cyclability with capacity retention of 80%after 500 cycles.In situ and ex situ experimental analyses and theoretical calculations reveal that the superior performance is primarily due to the maintaining of the amorphous state during the charge/discharge process to endow high stability and accelerated intercalation/deintercalation of large-sized Na^(+)without lattice constraints.Furthermore,the amorphous cathode materials show promising electrochemical properties in lithium-,potassium-and zinc-ion batteries,highlighting their broad adaptability and potential across various battery systems.
基金financially supported by the Yancheng Polytechnic College School-Level Scientific Research, China (No. ygy1903)the National Natural Science Foundation of China (Nos. 52001163, 52075237, and 52371157)+2 种基金the Open Project of Taihu Laboratory of Deep-Sea Technology Science, Key Research and Development Plan of Jiangsu Province, China (No. BE2019119)supported by the Priority Academic Program Development of Jiangsu Higher Education Institution (PAPD), Chinathe research funding for the Jiangsu Specially-Appointed Professor Program, China。
文摘Recent advancements in electrocatalysis have highlighted the exceptional application value of amorphous electrocatalysts. Withtheir unique atomic configurations, these electrocatalysts exhibit superior catalytic performance compared to that of their crystalline coun-terparts. Transition metal(TM) amorphous ribbon-shaped electrocatalysts have recently emerged as a new frontier in the catalysis field.Dealloying is widely considered a fascinating method for enhancing the electrocatalyst performance. In this review, we comprehensivelyexamine the principles of water electrolysis, discuss the prevalent methods for fabricating ribbon-configured electrocatalysts, and providean overview of amorphous alloys. Furthermore, we discuss binary, ternary, and high-entropy amorphous TM-based electrocatalysts,which satisfy the requirements necessary for effective water electrolysis. We also propose strategies to enhance the activity of amorphousTM-based ribbons, including morphology control, defect engineering, composition optimization, and heterostructure creation in differentelectrolytes. Our focus extends to the latest developments in the design of heterogeneous micro/nanostructures, management of prepara-tion techniques, and synthesis of different compositions. Finally, we address the ongoing challenges and provide a perspective on the fu-ture development of broadly applicable, self-supporting TM ribbon-shaped electrocatalysts.
基金financially supported by the Key research and development project of Shandong province in China(Grant No.2022CXGC020308).
文摘Four types of resins,P1–P4,are used as binders for FeSiBC amorphous powder,which are then press-molded and heat-treated to fabricate magnetic powder cores(MPCs).By testing the permeability,loss,density,and radial crush strength of MPCs,the effect of the binder on the magnetic properties of the cores is investigated and the best resin is found.The results show that the silicone resin P3 exhibits the best thermal stability,retaining 82.1%of its mass after heat treatment at 430°C.This contributes to improving the insulation of MPCs and reducing the eddy current loss,which is 46.06 mW cm^(−3)(150 kHz,20 mT)with the mechanical strength of 11.13 MPa.The bonding of epoxy resin P4 is superior to that of other resins,which significantly improves the powder compactness and makes MPCs density reach 5.67 g cm^(−3),and its permeability is as high as 28.7.The two types of resins have different advantages,and both lead to MPCs with excellent properties.
基金financial support from the National Key Research and Development Project of China(No.2022YFE0113800)the Natural Science Foundation of Zhejiang Province(No.LY23E020010)+1 种基金the National Natural Science Foundation of China(Nos.U21A20174 and 52225208)the funding from China Postdoctoral Science Foundation(No.2023M743098)。
文摘The in-depth study of the transport properties of the solid electrolyte interface(SEI)is crucial for the development of ultra-high-rate,and long lifespan sodium-ion batteries(SIBs).However,there remains a lack of theoretical investigation into the transport mechanisms of the main inorganic components of the SEI,namely Na F,Na_(2)O,and Na_(2)CO_(3).To address this research gap,we performed classical molecular dynamics simulations in this work to study the diffusion mechanisms of sodium ions in these inorganic components of the SEI,with special emphasis on the impact of the amorphous SEI environment on the diffusion behavior of sodium ions.The results have shown that amorphous SEI components significantly enhance the diffusion rate of sodium ions at room temperature compared to crystalline components.Within these amorphous SEI components,we reveal that the diffusion coefficients of sodium ions in amorphous Na_(2)O and Na_(2)CO_(3)are more than an order of magnitude higher than that of Na F,suggesting that amorphous Na_(2)O and Na_(2)CO_(3)are more effective in facilitating the Na ion diffusion.Analysis of the local atomic structure indicates that the amorphous local structures are dominant in Na_(2)O and Na_(2)CO_(3)at room temperature,maintaining a disordered amorphous phase.In contrast,amorphous Na F undergoes a spontaneously transformation into an ordered structure,exhibiting crystalline characteristics that restrict the diffusion of sodium ions.In summary,our work provides atomic insights into the impact of local amorphous environments on Na ion diffusion in SEI and suggests that amorphous SEI components play a critical role in improving battery performance.
基金supported by the National Natural Science Foundation of China(No.52471184)the Science and Technology Major Project of Hunan Province,China(No.2019GK1012)+1 种基金the Postgraduate Scientific Research Innovation Project of Xiangtan University,China(No.XDCX2023Y174)the Postgraduate Scientific Research Innovation Project of Xiangtan University,China(No.XDCX2023Y173).
文摘In order to develop a generic framework capable of designing novel amorphous alloys with selected target properties,a predictor−corrector inverse design scheme(PCIDS)consisting of a predictor module and a corrector module was presented.A high-precision forward prediction model based on deep neural networks was developed to implement these two parts.Of utmost importance,domain knowledge-guided inverse design networks(DKIDNs)and regular inverse design networks(RIDNs)were also developed.The forward prediction model possesses a coefficient of determination(R^(2))of 0.990 for the shear modulus and 0.986 for the bulk modulus on the testing set.Furthermore,the DKIDNs model exhibits superior performance compared to the RIDNs model.It is finally demonstrated that PCIDS can efficiently predict amorphous alloy compositions with the required target properties.
基金financially supported by National Natural Science Foundation of China(22278170,52172058)Natural Science Foundation of Anhui Province(2408085QB037)+3 种基金Natural Science Foundation of Anhui Provincial Department of Education(2023AH020042,2024AH051721)financial support from High-Level Talents Introduction and Cultivation Plan of Anhui Province-Young Top Talent,Huainan Innovation and Entrepreneurship Star Team(HNSTD-2024),Huainan Research Center of New Carbon Energy Materials(HNSPT02)New Energy Materials and Technology Research Center of Huainan Normal University.Business Finland,BATCircle2.0 project(Grant No.44612/31/2020)is acknowledged for financial supportU.L.acknowledges Finnish Research Impact Foundation for Tandem Industry Academy Professorship funding in 2023-2025.
文摘Amorphous transition metal compounds(a-TMC)become one of the most promising pre-catalysts toward oxygen evolution reaction(OER)due to their high-entropy nature and flexible self-reconstruction to highly active derivatives.However,the loosen bonds inside the amorphous structure make it an electronic insulator with unstable structure.Here,monodispersed Ni^(2+)-phytate nanospheres implanted by Fe^(3+)ions(NS_(FeNiPA))were firstly prepared and subsequently transferred into homogeneous high-entropy type Fe-Ni-P-O-C amorphous nanospheres(CNS_(FeNiPO)).It is shown that the CNS_(FeNiPO) presents robust structure and remarkable Fe ions migration during potential-driven activation process,which benefits efficient surface reconstruction and spherical morphology preservation.The CNS_(FeNiPO) with low mass loading of 0.1mg/cm^(2)could deliver small overpotential of 270mV at 10mAcm^(−2)and almost 100%retention of the initial current density after 10h test.The improved electrocatalytic activity is attributed to the boosted electron transfer from Ni sites to O-containing intermediates by introduction of Fe and P atoms.Moreover,rechargeable Zn-air battery with CNS_(FeNiPO)+Pt/C could achieve lower charge potential platform and better cycling performance than that with commercial RuO_(2)+Pt/C.This work provides new insights into the design and understanding of high-entropy amorphous pre-catalysts toward OER.
基金supported by National Natural Science Foundation of China(Nos.52073199,52274304)。
文摘The core@shell structure materials with the synergistic effect have been confirmed as promising catalysts for oxygen evolution reaction(OER).However,the conventional catalysts with crystalline phase suffer from deficient active sites,elemental dissolution,and structural collapse during OER catalysis,which results in the limited OER performance.Herein,we introduced the amorphous phase structure by controllable wet-chemical sulfuration strategy,thus to prepare the amorphous/crystalline(a/c)Ag S@Co S core@shell catalysts.Benefitting from the core@shell construction with synergistic interaction,a/c heterophase with well-balanced catalytic activity and stability,favorable sulfides components with positive oxysulfide reconstructed layer formation,the optimized Ag S@CoS-2 catalysts displayed superior OER catalytic behaviors with a low overpotential of 260 m V and Tafel slope of 64.4 m V/dec on the current density of 10 m A/cm^(2),surpassing the counterpart catalysts and commercial RuO_(2)catalysts.Meanwhile,the Ag S@CoS-2 catalysts possessed remarkable OER catalytic stability,as well as the favorable overall water splitting performance.
