Inelastic collisions are the dominant cause of energy loss in radiotherapy.In the energy range around the Bragg peak,single ionization(SI)and single-electron capture(SC)are the primary inelastic collisions that lead t...Inelastic collisions are the dominant cause of energy loss in radiotherapy.In the energy range around the Bragg peak,single ionization(SI)and single-electron capture(SC)are the primary inelastic collisions that lead to energy loss.This study employs the classical trajectory Monte Carlo method to study the SI and SC processes of H_(2)O molecules using He^(2+) and C^(6+) projectiles in the energy range of 10 keV/u to 10 MeV/u.The total cross sections,single differential cross sections,impact parameter dependence of SI and SC,and fragmentation cross sections were investigated.Results illustrate that the cross section for SI is the highest when the projectile energy is close to the Bragg peak energy.When the projectile energy is below the Bragg peak energy,the ionized electrons in the forward direction dominate,and the removal of electrons can be associated with large impact parameters.As the projectile energy increases,the emission angle of the electrons gradually transitions from small angles(60°~120°)to large angles(60°~120°),and the removal of electrons is associated with small impact parameters.The energy distributions of the ionized electron are similar when the projectile energy is equal to,below or above the Bragg peak energy.The fragmentation cross sections after SI and SC in the energy range around the Bragg peak were also estimated.展开更多
The core reactions for fuel cells,rechargeable metal-air batteries,and hydrogen fuel production are the oxygen reduction reaction(ORR),oxygen evolution reaction(OER),and hydrogen evolution reaction(HER),which are heav...The core reactions for fuel cells,rechargeable metal-air batteries,and hydrogen fuel production are the oxygen reduction reaction(ORR),oxygen evolution reaction(OER),and hydrogen evolution reaction(HER),which are heavily dependent on the efficiency of electrocatalysts.Enormous attempts have previously been devoted in non-noble electrocatalysts born out of metal-organic frameworks(MOFs)for ORR,OER,and HER applications,due to the following advantageous reasons:(i)The significant porosity eases the electrolyte diffusion;(ii)the supreme catalyst-electrolyte contact area enhances the diffusion efficiency;and(iii)the electronic conductivity can be extensively increased owing to the unique construction block subunits for MOFs-derived electrocatalysis.Herein,the recent progress of MOFs-derived electrocatalysts including synthesis protocols,design engineering,DFT calculations roles,and energy applications is discussed and reviewed.It can be concluded that the elevated ORR,OER,and HER performances are attributed to an advantageously well-designed high-porosity structure,significant surface area,and plentiful active centers.Furthermore,the perspectives of MOF-derived electrocatalysts for the ORR,OER,and HER are presented.展开更多
Metallic copper is widely used as current collector(CC) for graphite anode of lithium-ion batteries(LIBs) due to its high electrical conductivity and electrochemical stability. However, the large volume density of com...Metallic copper is widely used as current collector(CC) for graphite anode of lithium-ion batteries(LIBs) due to its high electrical conductivity and electrochemical stability. However, the large volume density of commercial copper foil(~8.9 g·cm^(-3)) limits the increase of energy density of battery. Here, copper-coated porous polyimide(Cu@PPI) was prepared by vacuum evaporation as collector for the graphite anode. The sandwich structure connects the copper metal on both sides of the collector with excellent electrical conductivity. Compared to commercial Cu foil, Cu@PPI has lighter mass(≤3.9 mg for disc of 12 mm diameter versus 9.9 mg of ~10 μm Cu foil) and lower volume density(≤3.3 g·cm^(-3)). In addition, the porous structure allows of better adhesion of reactive substances and electrochemical properties than pure Cu foils. It is estimated that the energy density of Cu@PPI should be much higher than that of Cu foil. This strategy should be applicable for other current collectors.展开更多
Thermo-electro-magnetic materials with simultaneously large magnetocaloric(MC)and thermoelectric(TE)effects are the core part for designing TE/MC all-solid-state cooling devices.Compositing MC phase with TE material i...Thermo-electro-magnetic materials with simultaneously large magnetocaloric(MC)and thermoelectric(TE)effects are the core part for designing TE/MC all-solid-state cooling devices.Compositing MC phase with TE material is an effective approach.However,the elemental diffusion and chemical reaction occurring at the two-phase interfaces could significantly impair the cooling performance.Herein,Gd/Bi_(0.5)Sb_(1.5)Te_(3)(Gd/BST)composites were prepared by a low-temperature high-pressure spark plasma sintering method with an aim to control the extent of interfacial reaction.The reaction of Gd with the diffusive Te and the formation of GdTe nanocrystals were identified at the Gd/BST interfaces by the atomic-resolution microscope.The formed Bi’_(Te)antisite defects and enhanced{000 l}preferential orientation in BST are responsible for the increased carrier concentration and mobility,which leads to optimized electrical properties.The heterogeneous interface phases,along with antisite defects,favor the phonon scattering enhancement and lattice thermal conductivity suppression.The optimized composite sintered at 693 K exhibited a maximum ZT of 1.27 at 300 K.Furthermore,the well-controlled interfacial reaction has a slight impact on the magnetic properties of Gd and a high magnetic entropy change is retained in the composites.This work provides a universal approach to fabricating thermo-electro-magnetic materials with excellent MC and TE properties.展开更多
All-perovskite tandem solar cells(ATSCs) have the potential to surpass the Shockley-Queisser efficiency limit of conventional single-junction devices. However, the performance and stability of mixed tin–lead(Sn–Pb) ...All-perovskite tandem solar cells(ATSCs) have the potential to surpass the Shockley-Queisser efficiency limit of conventional single-junction devices. However, the performance and stability of mixed tin–lead(Sn–Pb) perovskite solar cells(PSCs), which are crucial components of ATSCs, are much lower than those of lead-based perovskites. The primary challenges include the high crystallization rate of perovskite materials and the susceptibility of Sn^(2+) oxidation, which leads to rough morphology and unfavorable p-type self-doping. To address these issues, we introduced ethylhydrazine oxalate(EDO) at the perovskite interface, which effectively inhibits the oxidation of Sn^(2+) and simultaneously enhances the crystallinity of the perovskite. Consequently, the EDO-modified mixed tin-lead PSCs reached a power conversion efficiency(PCE) of 21.96% with high reproducibility. We further achieved a 27.58% efficient ATSCs by using EDO as interfacial passivator in the Sn-Pb PSCs.展开更多
Mechanical metamaterials refer to a class of composite materials with artificially designed structures and exhibit extraordinary mechanical properties that traditional materials do not have.Among them,energy absorptio...Mechanical metamaterials refer to a class of composite materials with artificially designed structures and exhibit extraordinary mechanical properties that traditional materials do not have.Among them,energy absorption mechanical metamaterials can absorb mechanical energy more efficiently,which requires the material itself to have both high strength and high strain capacity.But in general,high strength and high strain capacity of materials are difficult to obtain at the same time.展开更多
Carbon dioxide accounts for about 80 percent of greenhouse emissions and the increasing CO_(2)emission has been identified as a critical environmental issue.On the other hand,CO_(2)is a potentially renewable resource ...Carbon dioxide accounts for about 80 percent of greenhouse emissions and the increasing CO_(2)emission has been identified as a critical environmental issue.On the other hand,CO_(2)is a potentially renewable resource of a single carbon molecule,and new technologies to utilize CO_(2)in producing net-zero fuels and chemicals are of global interest.Great efforts have been made in the development of new materials and processes for CO_(2)capture and utilization(CCU).Among them,ionic liquids(ILs)have attracted much attention due to their unique characteristics such as high CO_(2)solubility,high ionic conductivity,negligible volatility,non-flammability,wide electrochemical window,and high thermal stability,as well as good solvation ability.This review summarizes the most recent efforts devoted to IL-based absorption,catalysts,and CO_(2)capture and utilization processes.We discuss the factors that affect the interaction between ILs and CO_(2),impacting on the viscosity and CO_(2)solubility and preview the coupling of CO_(2)capture with electrochemical conversion of CO_(2).Finally,we provide an overview on the advantages and disadvantages of the IL-based process for practical applications.展开更多
We present a study of magnetic transport and radiation properties during compression of a magnetized laboratory plasma.A theta pinch is used to produce a magnetized plasma column undergoing radial implosion,with plasm...We present a study of magnetic transport and radiation properties during compression of a magnetized laboratory plasma.A theta pinch is used to produce a magnetized plasma column undergoing radial implosion,with plasma parameters comprehensively measured through diverse diagnostic techniques.High-resolution observations show the implosion progressing through three stages:compression,expansion,and recompression.An anomalous demagnetization phenomenon is observed during the first compression stage,wherein the magnetic field at the plasma center is depleted as the density increases.We reveal the demagnetization mechanism and formulate a straightforward criterion for determining its occurrence,through analysis based on extended-magnetohydrodynamics theory and a generalized Ohm’s law.Additionally,we quantitatively evaluate the radiation losses and magnetic field variations during the two compression stages,providing experimental evidence that magnetic transport can influence the radiation properties by altering the plasma hydrodynamics.Furthermore,extrapolated results using our findings reveal direct relevance to magnetized inertial confinement fusion,space,and astrophysical plasma scenarios.展开更多
Growth of high-quality Nb_(3)Sn thin films for superconducting radiofrequency(SRF)applications using the vapor diffusion method requires a uniform distribution of tin nuclei on the niobium(Nb)surface.This study examin...Growth of high-quality Nb_(3)Sn thin films for superconducting radiofrequency(SRF)applications using the vapor diffusion method requires a uniform distribution of tin nuclei on the niobium(Nb)surface.This study examines the mechanism underlying the observed non-uniform distribution of tin nuclei with tin chloride SnCl_(2).Electron backscatter diffraction(EBSD)analysis was used to examine the correlation between the nucleation behavior and orientation of niobium grains in the substrate.The findings of the density functional theory(DFT)simulation are in good agreement with the experimental results,showing that the non-uniform distribution of tin nuclei is the result of the adsorption energy of SnCl_(2)molecules by varied niobium grain orientations.Further analysis indicated that the surface roughness and grain size of niobium also played significant roles in the nucleation behavior.This study provides valuable insights into enhancing the surface pretreatment of niobium substrates during the growth of Nb_(3)Sn thin films using the vapor diffusion method.展开更多
Automatic phase-setting is essential for modern linacs which have increasingly stringent time demands for beam tune-up and fault compensation.A key challenge in automatic phase-setting is obtaining an accurate knowled...Automatic phase-setting is essential for modern linacs which have increasingly stringent time demands for beam tune-up and fault compensation.A key challenge in automatic phase-setting is obtaining an accurate knowledge of the position and phase offsets of all cavities.This study proposes a beam-based method that employs time-of-flight experiments for simultaneous alignment and phase calibration of a superconducting hadron linac.The proposed method is verified using the CAFE2 accelerator at the Institute of Modern Physics,where offset measurements enable rapid tune-up via automatic phase-setting,and the output beam energies closely match the predicted values.The proposed method is able to address longitudinal position shifts within cryomodules due to cool-down,readily applicable to superconducting hadron linacs,and expected to be employed in the upcoming commissioning of CiADS and HIAF.展开更多
Vapor deposition is a promising technique for industrializing perovskite solar cells,but limited understanding of crystallization mechanisms in vapor-phase processes hampers progress.This study reveals a top-down crys...Vapor deposition is a promising technique for industrializing perovskite solar cells,but limited understanding of crystallization mechanisms in vapor-phase processes hampers progress.This study reveals a top-down crystallization growth mechanism during a two-step vapor-solid reaction and introduces an accelerated diffusion-buried homogeneous seed(AD-BHS)strategy.By utilizing the rapid diffusion of methylammonium chloride and inducing crystallization with buried seeds,we eliminate residual lead iodide,reduce crystallization time disparities across the film,and enhance uniformity.As a result,we achieve efficiencies of 22.40%for small-area(0.148 cm^(2))cells and 19.75%for large-area(10.0 cm^(2))modules,both representing state-of-the-art performance for vapor-solid reaction-based perovskite solar cells.This study provides critical insights into regulating crystallization growth in vapor-deposited perovskite thin films.展开更多
Early diagnosis and accurate boundary delineation are the key steps of tumor precision medicine.Circulating tumor cells(CTCs)detection of liquid biopsy can provide abundant information for early diagnosis of cancer.Hi...Early diagnosis and accurate boundary delineation are the key steps of tumor precision medicine.Circulating tumor cells(CTCs)detection of liquid biopsy can provide abundant information for early diagnosis of cancer.High detection specificity and good enrichment features are two key factors for CTCs accurate identification in peripheral blood sample.For this purpose,iron oxide(IO)-based surface-enhanced Raman scattering(SERS)bioprobes with good biocompatibility,high detection sensitivity,remarkable detection specificity,and good enrichment efficiency,were developed for detecting different types of CTCs.Magnetic SERS bioprobes combined with programmed death ligand-1(PD-L1)antibody are regarded as an effective way to boost the targeting ability and detection specificity,benefiting for accurately capturing and identifying rare CTCs.Four types of CTCs with different PD-L1 expression were accurately distinguished among white blood cells via high-resolution SERS mapping images and stable Raman signals.Subsequently,CTCs blood samples obtained from the triple negative breast cancer patients were also successfully recognized compared to that of health people,indicating IO@AR@PDA-a PD-L1 SERS bioprobe possessed great potential for CTCs detection in liquid biopsy.Additionally,IO-based bioprobe exhibited excellent dual-modal imaging abilities of high-resolution SERS imaging mode and microimaging magnetic resonance imaging mode.These two highly complementary imaging modes endowed IO-based bioprobes unrivalled capacity in tumor boundary differentiation,supporting tumor accurate resection and precise surgery.To our best knowledge,this is the first time that biocompatible IO-based SERS bioprobes without noble metal element were reported not only for CTCs accurate detection,but also for precise tumor boundary delineation,showing great advantages in tumor diagnosis and treatment.展开更多
This study employed a microwave-ultrasonic-hydrothermal multifield coupling method to synthesize nanoβ-Tricalcium phosphate(β-TCP)powder,systematically evaluating the impact of various parameters,including reaction ...This study employed a microwave-ultrasonic-hydrothermal multifield coupling method to synthesize nanoβ-Tricalcium phosphate(β-TCP)powder,systematically evaluating the impact of various parameters,including reaction temperature,time,sintering temperature,reactant types and concentrations,and graphene oxide(GO)concentration,on the physicochemical properties of the nanoβ-TCP powder.The synthesized powder was characterized using X-ray diffraction(XRD),Fourier-transform infrared spectroscopy(FTIR),scanning electron microscopy(SEM),high-resolution transmission electron microscopy(HRTEM),inductively coupled plasma optical emission spectroscopy(ICP-OES),and thermogravimetric-differential scanning calorimetry(TG-DSC).The experimental results indicate that the optimal synthesis conditions are achieved with a 0.6 mol/L Ca(NO3)2·4H2O solution and a 0.4 mol/L(NH_(4))_(2)HPO_(4)solution at a reaction temperature of 35℃for 40 minutes,followed by sintering at 720℃for 2 hours with 1×10^(-1)g/L GO.The preparedβ-TCP powder exhibits high crystallinity,a pure phase,good dispersibility,no significant aggregation,and uniform particle size of 59.75±12.84 nm.In vitro cytotoxicity tests show excellent biocompatibility and no cytotoxic effects on bone marrow stromal cells(BMSCs)even at concentrations up to 0.8 mg/mL.Furthermore,results from live-dead staining and nuclear membrane staining of cells co-cultured with the material demonstrate that theβ-TCP can promote the proliferation and differentiation of BMSCs to a certain extent,highlighting its potential as a safe and effective material for bone tissue engineering.展开更多
To improve the controlled release ability,we prepared attapulgite into microspheres by spray drying.This research began with a thorough thermogravimetric analysis to optimize attapulgite's heat treatment for drug ...To improve the controlled release ability,we prepared attapulgite into microspheres by spray drying.This research began with a thorough thermogravimetric analysis to optimize attapulgite's heat treatment for drug loading.By advanced spray drying,attapulgite was transformed into microspheres,refining its drug release characteristics.Various parameters were examined,achieving optimal particle size and morphology at 25%solid content,2.5%dispersant,and 3% binder.Attapulgite microspheres demonstrated exceptional encapsulation efficiency,exceeding 95% for doxorubicin hydrochloride,highlighting their versatility in drug delivery.FTIR and XRD were used to predict changes in material properties after spray drying.Notably,cytotoxicity tests confirmed the high biocompatibility of attapulgite microspheres,devoid of cell death induction.Attapulgite microsphere loaded with doxorubicin enable sustained drug release and maintain killing ability against tumor cells.This study confirms the viability of spray dried attapulgite microspheres for efficient drug loading and delivery and provides insights for innovative drug delivery systems that utilize the unique properties of attapulgite to advance therapeutics.展开更多
Cr coatings,as protective coatings of Zr-alloy fuel claddings,inevitably suffer from irradiation damage before they would possibly run into the accident condition.This study evaluates the radiation and oxidation toler...Cr coatings,as protective coatings of Zr-alloy fuel claddings,inevitably suffer from irradiation damage before they would possibly run into the accident condition.This study evaluates the radiation and oxidation tolerance of three Cr-based coatings with different microstructures(Cr,CrAlSi,and CrAlSiN)through He2+ion irradiation and 1200℃ steam oxidation.The Cr and CrAlSi coatings experienced significant structural degradation,characterized by He bubble aggregation and amplified Kirkendall effects at elevated temperatures.In contrast,the irradiated CrAlSiN coating maintained structural integrity without measurable irradiation hardening.Following annealing at 800℃ for 30 min,approximately 40%of injected He atoms were released,indicating a“self-healing”mechanism.The mechanism is attributed to uniformly distributed,low-density channels that act as sinks and release paths for irradiation-induced defects.Density functional theory simulations suggest that N atoms promote significant rearrangement of ions surrounding the free volume,inhibiting the formation of sites capable of trapping He atoms.Moreover,the CrAlSiN coating exhibited superior oxidation resistance compared to the Cr and CrAlSi coatings,even under high-temperature steam conditions.Notably,the irradiated CrAlSiN sample displayed a significantly thinner oxide scale compared to the pristine one(almost half),owing to a more protective oxide scale and rapid outward diffusion of Cr,Al,and Si through nanochannel veins.These findings illuminate the effects of structure and composition on irradiation and oxidation behavior in Cr-based coatings,offering insights for developing new-generation accident-tolerance fuel coatings for Zr-alloy claddings.展开更多
We report the results of the experiment on synthesizing ^(287,288)Mc isotopes (Z=115) using the fusionevaporation reaction ^(243)Am(^(48)Ca,4n,3n)^(287,288)Mc at the Spectrometer for Heavy Atoms and Nuclear Structure-...We report the results of the experiment on synthesizing ^(287,288)Mc isotopes (Z=115) using the fusionevaporation reaction ^(243)Am(^(48)Ca,4n,3n)^(287,288)Mc at the Spectrometer for Heavy Atoms and Nuclear Structure-2(SHANS2),a gas-filled recoil separator located at the China Accelerator Facility for Superheavy Elements(CAFE2).In total,20 decay chains are attributed to ^(288)Mc and 1 decay chain is assigned to ^(287)Mc.The measured oa-decay properties of ^(287,288)Mc as well as its descendants are consistent with the known data.No additional decay chains originating from the 2n or 5n reaction channels were detected.The excitation function of the ^(243)Am(^(48)Ca,3n)^(288)Mc reaction was measured at the cross-section level of picobarn,which indicates the promising capability for the study of heavy and superheavy nuclei at the facility.展开更多
Energy and environmental issues are becoming more and more severe and renewable energy storage technologies are vital to solve the problem.Rechargeable metal(Li,Na,Mg,Al)-sulfur batteries with low-cost and earth-abund...Energy and environmental issues are becoming more and more severe and renewable energy storage technologies are vital to solve the problem.Rechargeable metal(Li,Na,Mg,Al)-sulfur batteries with low-cost and earth-abundant elemental sulfur as the cathode are attracting more and more interest for electrical energy storage in recent years.Lithium-sulfur(Li-S),room-temperature sodium-sulfur(RT Na-S),magnesium-sulfur(Mg-S)and aluminum-sulfur(Al-S)batteries are the most prominent candidates among them.Many obvious obstacles are hampering the developments of metal-sulfur batteries.Li-S and Na-S batteries are encumbered mainly by anode dendrite issues,polysulfides shuttle and low conductivity of cathodes.Mg-S and Al-S batteries are short of suitable electrolytes.In this review,relationships between various employed nanostructured materials and electrochemical performances of metal-sulfur batteries have been demonstrated.Moreover,the selections of suitable electrolytes,anode protection,separator modifications and prototype innovations are all crucial to the developments of metal-sulfur batteries and are discussed at the same time.Herein,we give a review on the advances of Li-S,RT Na-S,Mg-S and Al-S batteries from the point of view of materials,and then focus on perspectives of their future developments.展开更多
Exploring low-cost and earth-abundant oxygen reduction reaction(ORR)electrocatalyst is essential for fuel cells and metal–air batteries.Among them,non-metal nanocarbon with multiple advantages of low cost,abundance,h...Exploring low-cost and earth-abundant oxygen reduction reaction(ORR)electrocatalyst is essential for fuel cells and metal–air batteries.Among them,non-metal nanocarbon with multiple advantages of low cost,abundance,high conductivity,good durability,and competitive activity has attracted intense interest in recent years.The enhanced ORR activities of the nanocarbons are normally thought to originate from heteroatom(e.g.,N,B,P,or S)doping or various induced defects.However,in practice,carbon-based materials usually contain both dopants and defects.In this regard,in terms of the co-engineering of heteroatom doping and defect inducing,we present an overview of recent advances in developing non-metal carbon-based electrocatalysts for the ORR.The characteristics,ORR performance,and the related mechanism of these functionalized nanocarbons by heteroatom doping,defect inducing,and in particular their synergistic promotion effect are emphatically analyzed and discussed.Finally,the current issues and perspectives in developing carbon-based electrocatalysts from both of heteroatom doping and defect engineering are proposed.This review will be beneficial for the rational design and manufacturing of highly efficient carbon-based materials for electrocatalysis.展开更多
Due to its abundant sodium content and low cost,sodium-ion battery(SIB)has become an effective substitute and supplement for lithium-ion batteries,which has a broad development prospect in largescale energy storage sy...Due to its abundant sodium content and low cost,sodium-ion battery(SIB)has become an effective substitute and supplement for lithium-ion batteries,which has a broad development prospect in largescale energy storage systems.Na-super-ionic conductor(NASICON)structural materials have stable 3D skeleton structures and open Na+transport channels,which is a very promising SIB cathode material.But in the typical NASICON material Na_(3)V_(2)(PO_(4))_(3)(NVP),the number of electrons involved in NVP per formula unit is less than 2 at the stable voltage window,which limits the further improvement of battery performance.In this work,we report another NASICON structured Na_(3)V_(4/3)Cr_(2/3)(PO_(4))_(3)@C(NVCP@C),which is obtained by Cr-doped NVP through spray drying.By taking full advantage of the voltage platforms of V^(5+/4+),V^(4+/3+),and V^(3+/2+)in the window of 1.5-4.4 V,NVCP@C delivered a high discharge capacity(175 mAh g^(-1))and durable cyclability(86%capacity retention for 2000 cycles).In-situ X-ray diffraction results demonstrate that the reversible structural evolution accompanies by solid-solution reaction and two-phase reaction mechanisms co-exist during charge/discharge processes.When coupled with Na^(+)preembedded hard carbon(HC),the assembled NVCP@C//HC full cell delivers a high capacity(105 mAh g^(-1))and long cycling performance(70%after 1000 cycles).This Cr-doped NVP method offers new insights into the design of high-energy NASICON-structured cathode materials.展开更多
The epitaxial heterostructure can be rationally designed based on the in situ growth of two compatible phases with lattice similarity,in which the modulated electronic states and tuned adsorption behaviors are conduci...The epitaxial heterostructure can be rationally designed based on the in situ growth of two compatible phases with lattice similarity,in which the modulated electronic states and tuned adsorption behaviors are conducive to the enhancement of electrocatalytic activity.Herein,theoretical simulations first disclose the charge transfer trend and reinforced inherent electron conduction around the epitaxial heterointerface between Ru clusters and Ni_(3)N substrate(cRu-Ni_(3)N),thus leading to the optimized adsorption behaviors and reduced activation energy barriers.Subsequently,the defectrich nanosheets with the epitaxially grown cRu-Ni_(3)N heterointerface are successfully constructed.Impressively,by virtue of the superiority of intrinsic activity and reaction kinetics,such unique epitaxial heterostructure exhibits remarkable bifunctional catalytic activity toward electrocatalytic OER(226 mV@20 mA cm^(−2))and HER(32 mV@10 mA cm^(−2))in alkaline media.Furthermore,it also shows great application prospect in alkaline freshwater and seawater splitting,as well as solar-to-hydrogen integrated system.This work could provide beneficial enlightenment for the establishment of advanced electrocatalysts with epitaxial heterointerfaces.展开更多
基金supported in part by the National Natural Science Foundation of China(Nos.12105327 and 11775108)the Hunan Provincial Innovation Foundation For Postgraduate(No.QL20220210)the Advanced Energy Science and Technology Guangdong Laboratory.
文摘Inelastic collisions are the dominant cause of energy loss in radiotherapy.In the energy range around the Bragg peak,single ionization(SI)and single-electron capture(SC)are the primary inelastic collisions that lead to energy loss.This study employs the classical trajectory Monte Carlo method to study the SI and SC processes of H_(2)O molecules using He^(2+) and C^(6+) projectiles in the energy range of 10 keV/u to 10 MeV/u.The total cross sections,single differential cross sections,impact parameter dependence of SI and SC,and fragmentation cross sections were investigated.Results illustrate that the cross section for SI is the highest when the projectile energy is close to the Bragg peak energy.When the projectile energy is below the Bragg peak energy,the ionized electrons in the forward direction dominate,and the removal of electrons can be associated with large impact parameters.As the projectile energy increases,the emission angle of the electrons gradually transitions from small angles(60°~120°)to large angles(60°~120°),and the removal of electrons is associated with small impact parameters.The energy distributions of the ionized electron are similar when the projectile energy is equal to,below or above the Bragg peak energy.The fragmentation cross sections after SI and SC in the energy range around the Bragg peak were also estimated.
基金This work was supported by the National Natural Science Foundation of China(22075223,51701146).
文摘The core reactions for fuel cells,rechargeable metal-air batteries,and hydrogen fuel production are the oxygen reduction reaction(ORR),oxygen evolution reaction(OER),and hydrogen evolution reaction(HER),which are heavily dependent on the efficiency of electrocatalysts.Enormous attempts have previously been devoted in non-noble electrocatalysts born out of metal-organic frameworks(MOFs)for ORR,OER,and HER applications,due to the following advantageous reasons:(i)The significant porosity eases the electrolyte diffusion;(ii)the supreme catalyst-electrolyte contact area enhances the diffusion efficiency;and(iii)the electronic conductivity can be extensively increased owing to the unique construction block subunits for MOFs-derived electrocatalysis.Herein,the recent progress of MOFs-derived electrocatalysts including synthesis protocols,design engineering,DFT calculations roles,and energy applications is discussed and reviewed.It can be concluded that the elevated ORR,OER,and HER performances are attributed to an advantageously well-designed high-porosity structure,significant surface area,and plentiful active centers.Furthermore,the perspectives of MOF-derived electrocatalysts for the ORR,OER,and HER are presented.
基金supported by the 2019 Foshan Science and Technology Innovation Team(No.1920001000108)Guangdong Basic and Applied Basic Research Foundation(No.2021A1515111103)+2 种基金Guangzhou Science and Technology Plan Project(No.202201010867)Science and Technology Major Project of Guangdong Province(No.220110165851234)the National Key R&D Program of China(No.2020YFB0408100).
文摘Metallic copper is widely used as current collector(CC) for graphite anode of lithium-ion batteries(LIBs) due to its high electrical conductivity and electrochemical stability. However, the large volume density of commercial copper foil(~8.9 g·cm^(-3)) limits the increase of energy density of battery. Here, copper-coated porous polyimide(Cu@PPI) was prepared by vacuum evaporation as collector for the graphite anode. The sandwich structure connects the copper metal on both sides of the collector with excellent electrical conductivity. Compared to commercial Cu foil, Cu@PPI has lighter mass(≤3.9 mg for disc of 12 mm diameter versus 9.9 mg of ~10 μm Cu foil) and lower volume density(≤3.3 g·cm^(-3)). In addition, the porous structure allows of better adhesion of reactive substances and electrochemical properties than pure Cu foils. It is estimated that the energy density of Cu@PPI should be much higher than that of Cu foil. This strategy should be applicable for other current collectors.
基金supported by the National Key Research and Development Program of China(2019YFA0704903)National Natural Science Foundation of China(11834012,52130203,92163122,91963207,91963122)
文摘Thermo-electro-magnetic materials with simultaneously large magnetocaloric(MC)and thermoelectric(TE)effects are the core part for designing TE/MC all-solid-state cooling devices.Compositing MC phase with TE material is an effective approach.However,the elemental diffusion and chemical reaction occurring at the two-phase interfaces could significantly impair the cooling performance.Herein,Gd/Bi_(0.5)Sb_(1.5)Te_(3)(Gd/BST)composites were prepared by a low-temperature high-pressure spark plasma sintering method with an aim to control the extent of interfacial reaction.The reaction of Gd with the diffusive Te and the formation of GdTe nanocrystals were identified at the Gd/BST interfaces by the atomic-resolution microscope.The formed Bi’_(Te)antisite defects and enhanced{000 l}preferential orientation in BST are responsible for the increased carrier concentration and mobility,which leads to optimized electrical properties.The heterogeneous interface phases,along with antisite defects,favor the phonon scattering enhancement and lattice thermal conductivity suppression.The optimized composite sintered at 693 K exhibited a maximum ZT of 1.27 at 300 K.Furthermore,the well-controlled interfacial reaction has a slight impact on the magnetic properties of Gd and a high magnetic entropy change is retained in the composites.This work provides a universal approach to fabricating thermo-electro-magnetic materials with excellent MC and TE properties.
基金financially supported by National Key R&D Program of China (2025YFE0100300)the National Natural Science Foundation of China (52202293 and 52330004)the Fundamental Research Funds for the Central Universities (WUT: 2023IVA075 and 2023IVB009)。
文摘All-perovskite tandem solar cells(ATSCs) have the potential to surpass the Shockley-Queisser efficiency limit of conventional single-junction devices. However, the performance and stability of mixed tin–lead(Sn–Pb) perovskite solar cells(PSCs), which are crucial components of ATSCs, are much lower than those of lead-based perovskites. The primary challenges include the high crystallization rate of perovskite materials and the susceptibility of Sn^(2+) oxidation, which leads to rough morphology and unfavorable p-type self-doping. To address these issues, we introduced ethylhydrazine oxalate(EDO) at the perovskite interface, which effectively inhibits the oxidation of Sn^(2+) and simultaneously enhances the crystallinity of the perovskite. Consequently, the EDO-modified mixed tin-lead PSCs reached a power conversion efficiency(PCE) of 21.96% with high reproducibility. We further achieved a 27.58% efficient ATSCs by using EDO as interfacial passivator in the Sn-Pb PSCs.
基金National Natural Science Foundation of China(U1932210)Key Research Program of Frontier Sciences,CAS(QYZDB-SSW-SLH010)。
文摘Mechanical metamaterials refer to a class of composite materials with artificially designed structures and exhibit extraordinary mechanical properties that traditional materials do not have.Among them,energy absorption mechanical metamaterials can absorb mechanical energy more efficiently,which requires the material itself to have both high strength and high strain capacity.But in general,high strength and high strain capacity of materials are difficult to obtain at the same time.
基金supported by the National Natural Science Foundation of China(21972027)the Foshan Xianhu Laboratory(41220103,41210501,XHD2021-001,XHD2022001,492305,472303)。
文摘Carbon dioxide accounts for about 80 percent of greenhouse emissions and the increasing CO_(2)emission has been identified as a critical environmental issue.On the other hand,CO_(2)is a potentially renewable resource of a single carbon molecule,and new technologies to utilize CO_(2)in producing net-zero fuels and chemicals are of global interest.Great efforts have been made in the development of new materials and processes for CO_(2)capture and utilization(CCU).Among them,ionic liquids(ILs)have attracted much attention due to their unique characteristics such as high CO_(2)solubility,high ionic conductivity,negligible volatility,non-flammability,wide electrochemical window,and high thermal stability,as well as good solvation ability.This review summarizes the most recent efforts devoted to IL-based absorption,catalysts,and CO_(2)capture and utilization processes.We discuss the factors that affect the interaction between ILs and CO_(2),impacting on the viscosity and CO_(2)solubility and preview the coupling of CO_(2)capture with electrochemical conversion of CO_(2).Finally,we provide an overview on the advantages and disadvantages of the IL-based process for practical applications.
基金the State Key Development Program for Basic Research of China(Grant No.2022YFA1602503)the National Natural Science Foundation of China(Grant Nos.12120101005 and 12205247)
文摘We present a study of magnetic transport and radiation properties during compression of a magnetized laboratory plasma.A theta pinch is used to produce a magnetized plasma column undergoing radial implosion,with plasma parameters comprehensively measured through diverse diagnostic techniques.High-resolution observations show the implosion progressing through three stages:compression,expansion,and recompression.An anomalous demagnetization phenomenon is observed during the first compression stage,wherein the magnetic field at the plasma center is depleted as the density increases.We reveal the demagnetization mechanism and formulate a straightforward criterion for determining its occurrence,through analysis based on extended-magnetohydrodynamics theory and a generalized Ohm’s law.Additionally,we quantitatively evaluate the radiation losses and magnetic field variations during the two compression stages,providing experimental evidence that magnetic transport can influence the radiation properties by altering the plasma hydrodynamics.Furthermore,extrapolated results using our findings reveal direct relevance to magnetized inertial confinement fusion,space,and astrophysical plasma scenarios.
基金supported by the National Natural Science Foundation of China(No.12175283)Youth Innovation Promotion Association of Chinese Academy of Sciences(2020410)Advanced Energy Science and Technology Guangdong Laboratory(HND20TDSPCD,HND22PTDZD).
文摘Growth of high-quality Nb_(3)Sn thin films for superconducting radiofrequency(SRF)applications using the vapor diffusion method requires a uniform distribution of tin nuclei on the niobium(Nb)surface.This study examines the mechanism underlying the observed non-uniform distribution of tin nuclei with tin chloride SnCl_(2).Electron backscatter diffraction(EBSD)analysis was used to examine the correlation between the nucleation behavior and orientation of niobium grains in the substrate.The findings of the density functional theory(DFT)simulation are in good agreement with the experimental results,showing that the non-uniform distribution of tin nuclei is the result of the adsorption energy of SnCl_(2)molecules by varied niobium grain orientations.Further analysis indicated that the surface roughness and grain size of niobium also played significant roles in the nucleation behavior.This study provides valuable insights into enhancing the surface pretreatment of niobium substrates during the growth of Nb_(3)Sn thin films using the vapor diffusion method.
基金supported by the National Natural Science Foundation of China(U22A20261)the Large Research Infrastructures China initiative Accelerator Driven System(2017-000052-75-01-000590).
文摘Automatic phase-setting is essential for modern linacs which have increasingly stringent time demands for beam tune-up and fault compensation.A key challenge in automatic phase-setting is obtaining an accurate knowledge of the position and phase offsets of all cavities.This study proposes a beam-based method that employs time-of-flight experiments for simultaneous alignment and phase calibration of a superconducting hadron linac.The proposed method is verified using the CAFE2 accelerator at the Institute of Modern Physics,where offset measurements enable rapid tune-up via automatic phase-setting,and the output beam energies closely match the predicted values.The proposed method is able to address longitudinal position shifts within cryomodules due to cool-down,readily applicable to superconducting hadron linacs,and expected to be employed in the upcoming commissioning of CiADS and HIAF.
基金financial support by the Joint Foundation for Innovation and Development of Hubei Natural Science Foundation(2023AFD032)Hubei Provincial Natural Science Foundation of China(2023AFA010)。
文摘Vapor deposition is a promising technique for industrializing perovskite solar cells,but limited understanding of crystallization mechanisms in vapor-phase processes hampers progress.This study reveals a top-down crystallization growth mechanism during a two-step vapor-solid reaction and introduces an accelerated diffusion-buried homogeneous seed(AD-BHS)strategy.By utilizing the rapid diffusion of methylammonium chloride and inducing crystallization with buried seeds,we eliminate residual lead iodide,reduce crystallization time disparities across the film,and enhance uniformity.As a result,we achieve efficiencies of 22.40%for small-area(0.148 cm^(2))cells and 19.75%for large-area(10.0 cm^(2))modules,both representing state-of-the-art performance for vapor-solid reaction-based perovskite solar cells.This study provides critical insights into regulating crystallization growth in vapor-deposited perovskite thin films.
基金supported by the funding from National Natural Science Foundation of China(Nos.32025021,12374390,31971292,82072032,82202274)Ningbo 3315 Innovative Teams Program(No.2019A-14-C)+6 种基金The member of Youth Innovation Promotion Association Foundation of CAS(No.2023310)Key Scientific and Technological Special Project of Ningbo City(Nos.2023Z209,2020Z189)National Key R&D Program of China(No.2019YFA0405603)Provincial Natural Science Foundation of Zhejiang(Nos.LQ23H180007,LQ23H180003)Zhejiang Province Science and Technology Plan of Traditional Chinese Medicine(No.2021KY085)Zhejiang Provincial Traditional Chinese Medicine Foundation(No.2021ZB04)the Major Medical and Health Science and Technology Project of Zhejiang Province(No.WKJ-ZJ-2002)。
文摘Early diagnosis and accurate boundary delineation are the key steps of tumor precision medicine.Circulating tumor cells(CTCs)detection of liquid biopsy can provide abundant information for early diagnosis of cancer.High detection specificity and good enrichment features are two key factors for CTCs accurate identification in peripheral blood sample.For this purpose,iron oxide(IO)-based surface-enhanced Raman scattering(SERS)bioprobes with good biocompatibility,high detection sensitivity,remarkable detection specificity,and good enrichment efficiency,were developed for detecting different types of CTCs.Magnetic SERS bioprobes combined with programmed death ligand-1(PD-L1)antibody are regarded as an effective way to boost the targeting ability and detection specificity,benefiting for accurately capturing and identifying rare CTCs.Four types of CTCs with different PD-L1 expression were accurately distinguished among white blood cells via high-resolution SERS mapping images and stable Raman signals.Subsequently,CTCs blood samples obtained from the triple negative breast cancer patients were also successfully recognized compared to that of health people,indicating IO@AR@PDA-a PD-L1 SERS bioprobe possessed great potential for CTCs detection in liquid biopsy.Additionally,IO-based bioprobe exhibited excellent dual-modal imaging abilities of high-resolution SERS imaging mode and microimaging magnetic resonance imaging mode.These two highly complementary imaging modes endowed IO-based bioprobes unrivalled capacity in tumor boundary differentiation,supporting tumor accurate resection and precise surgery.To our best knowledge,this is the first time that biocompatible IO-based SERS bioprobes without noble metal element were reported not only for CTCs accurate detection,but also for precise tumor boundary delineation,showing great advantages in tumor diagnosis and treatment.
基金Funded by the National Key R&D Program of China(No.2023YFC2412300)the Guangdong Basic and Applied Basic Research Foundation(No.2021B1515120091)the Technology Development Project of Shandong Weigao Orthopedic Materials Co.,Ltd.(No.20221h0074)。
文摘This study employed a microwave-ultrasonic-hydrothermal multifield coupling method to synthesize nanoβ-Tricalcium phosphate(β-TCP)powder,systematically evaluating the impact of various parameters,including reaction temperature,time,sintering temperature,reactant types and concentrations,and graphene oxide(GO)concentration,on the physicochemical properties of the nanoβ-TCP powder.The synthesized powder was characterized using X-ray diffraction(XRD),Fourier-transform infrared spectroscopy(FTIR),scanning electron microscopy(SEM),high-resolution transmission electron microscopy(HRTEM),inductively coupled plasma optical emission spectroscopy(ICP-OES),and thermogravimetric-differential scanning calorimetry(TG-DSC).The experimental results indicate that the optimal synthesis conditions are achieved with a 0.6 mol/L Ca(NO3)2·4H2O solution and a 0.4 mol/L(NH_(4))_(2)HPO_(4)solution at a reaction temperature of 35℃for 40 minutes,followed by sintering at 720℃for 2 hours with 1×10^(-1)g/L GO.The preparedβ-TCP powder exhibits high crystallinity,a pure phase,good dispersibility,no significant aggregation,and uniform particle size of 59.75±12.84 nm.In vitro cytotoxicity tests show excellent biocompatibility and no cytotoxic effects on bone marrow stromal cells(BMSCs)even at concentrations up to 0.8 mg/mL.Furthermore,results from live-dead staining and nuclear membrane staining of cells co-cultured with the material demonstrate that theβ-TCP can promote the proliferation and differentiation of BMSCs to a certain extent,highlighting its potential as a safe and effective material for bone tissue engineering.
基金Funded by the Major Special Projects of Technological Innovation of Hubei Province(No.2017ACA168)the Open Fund Project of Sanya Science and Education Innovation Park of Wuhan University of Technology(No.2021KF0012)the Guangdong Basic and Applied Basic Research Foundation(No.2021B1515120091)。
文摘To improve the controlled release ability,we prepared attapulgite into microspheres by spray drying.This research began with a thorough thermogravimetric analysis to optimize attapulgite's heat treatment for drug loading.By advanced spray drying,attapulgite was transformed into microspheres,refining its drug release characteristics.Various parameters were examined,achieving optimal particle size and morphology at 25%solid content,2.5%dispersant,and 3% binder.Attapulgite microspheres demonstrated exceptional encapsulation efficiency,exceeding 95% for doxorubicin hydrochloride,highlighting their versatility in drug delivery.FTIR and XRD were used to predict changes in material properties after spray drying.Notably,cytotoxicity tests confirmed the high biocompatibility of attapulgite microspheres,devoid of cell death induction.Attapulgite microsphere loaded with doxorubicin enable sustained drug release and maintain killing ability against tumor cells.This study confirms the viability of spray dried attapulgite microspheres for efficient drug loading and delivery and provides insights for innovative drug delivery systems that utilize the unique properties of attapulgite to advance therapeutics.
基金supported by the National Natu-ral Science Foundation of China(No.U2230126)the Natural Science Foundation of Zhejiang Province(No.LZ23E010001)+1 种基金This work was co-funded by the European Union under the Project Robotics and Advanced Industrial Production(Reg.No.CZ.02.01.01/00/22_008/0004590)supported by the Ministry of Education,Youth and Sports of the Czech Repub-lic through the e-INFRA CZ grant number ID:90140.Access to the computational infrastructure of the OP VVV funded Project No.CZ.02.1.01/0.0/0.0/16_019/0000765“Research Center for Informat-ics”and the use of the VESTA software[https://doi.org/10.1107/S0021889808012016]are also acknowledged.The authors thank the staffof HIRFL for the help with the irradiation experiment and the support of the Sharing Service Platform of CAS Large Re-search Infrastructures(2022-HIRFL-ZD-002017)。
文摘Cr coatings,as protective coatings of Zr-alloy fuel claddings,inevitably suffer from irradiation damage before they would possibly run into the accident condition.This study evaluates the radiation and oxidation tolerance of three Cr-based coatings with different microstructures(Cr,CrAlSi,and CrAlSiN)through He2+ion irradiation and 1200℃ steam oxidation.The Cr and CrAlSi coatings experienced significant structural degradation,characterized by He bubble aggregation and amplified Kirkendall effects at elevated temperatures.In contrast,the irradiated CrAlSiN coating maintained structural integrity without measurable irradiation hardening.Following annealing at 800℃ for 30 min,approximately 40%of injected He atoms were released,indicating a“self-healing”mechanism.The mechanism is attributed to uniformly distributed,low-density channels that act as sinks and release paths for irradiation-induced defects.Density functional theory simulations suggest that N atoms promote significant rearrangement of ions surrounding the free volume,inhibiting the formation of sites capable of trapping He atoms.Moreover,the CrAlSiN coating exhibited superior oxidation resistance compared to the Cr and CrAlSi coatings,even under high-temperature steam conditions.Notably,the irradiated CrAlSiN sample displayed a significantly thinner oxide scale compared to the pristine one(almost half),owing to a more protective oxide scale and rapid outward diffusion of Cr,Al,and Si through nanochannel veins.These findings illuminate the effects of structure and composition on irradiation and oxidation behavior in Cr-based coatings,offering insights for developing new-generation accident-tolerance fuel coatings for Zr-alloy claddings.
基金supported in part by the National Key R&D Program of China (Contract Nos.2023YFA1606500,2024YFE0109800,and 2024YFE0110400)Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB34010000)+5 种基金the Gansu Key Project of Science and Technology (Grant No.23ZDGA014)the Guangdong Major Project of Basic and Applied Basic Research (Grant No.2021B0301030006)the National Natural Science Foundation of China (Grant Nos.12105328,W2412040,12475126,12422507,12035011,12375118,12435008,and W2412043)the Chinese Academy of Sciences Project for Young Scientists in Basic Research(Grant No.YSBR-002)the Youth Innovation Promotion Association of the Chinese Academy of Sciences (Grant Nos.2020409 and 2023439)the Russian Science Foundation (Grant No.25-42-00003)。
文摘We report the results of the experiment on synthesizing ^(287,288)Mc isotopes (Z=115) using the fusionevaporation reaction ^(243)Am(^(48)Ca,4n,3n)^(287,288)Mc at the Spectrometer for Heavy Atoms and Nuclear Structure-2(SHANS2),a gas-filled recoil separator located at the China Accelerator Facility for Superheavy Elements(CAFE2).In total,20 decay chains are attributed to ^(288)Mc and 1 decay chain is assigned to ^(287)Mc.The measured oa-decay properties of ^(287,288)Mc as well as its descendants are consistent with the known data.No additional decay chains originating from the 2n or 5n reaction channels were detected.The excitation function of the ^(243)Am(^(48)Ca,3n)^(288)Mc reaction was measured at the cross-section level of picobarn,which indicates the promising capability for the study of heavy and superheavy nuclei at the facility.
基金supported by the National Natural Science Foundation of China(51702247,51832004,51521001)the National Key Research and Development Program of China(2020YFA0715004,2016YFA0202603)+1 种基金the Natural Science Foundation of Hubei Province(2019CFA001)the Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong Laboratory(XHT2020-003)。
文摘Energy and environmental issues are becoming more and more severe and renewable energy storage technologies are vital to solve the problem.Rechargeable metal(Li,Na,Mg,Al)-sulfur batteries with low-cost and earth-abundant elemental sulfur as the cathode are attracting more and more interest for electrical energy storage in recent years.Lithium-sulfur(Li-S),room-temperature sodium-sulfur(RT Na-S),magnesium-sulfur(Mg-S)and aluminum-sulfur(Al-S)batteries are the most prominent candidates among them.Many obvious obstacles are hampering the developments of metal-sulfur batteries.Li-S and Na-S batteries are encumbered mainly by anode dendrite issues,polysulfides shuttle and low conductivity of cathodes.Mg-S and Al-S batteries are short of suitable electrolytes.In this review,relationships between various employed nanostructured materials and electrochemical performances of metal-sulfur batteries have been demonstrated.Moreover,the selections of suitable electrolytes,anode protection,separator modifications and prototype innovations are all crucial to the developments of metal-sulfur batteries and are discussed at the same time.Herein,we give a review on the advances of Li-S,RT Na-S,Mg-S and Al-S batteries from the point of view of materials,and then focus on perspectives of their future developments.
基金the National Natural Science Foundation of China(51802104)Foundation of State Key Laboratory of Coal Combustion(FSKLCCA2008)State Key Laboratory of Advanced Technology for Materials Synthesis and Processing(Wuhan University of Technology)(2021-KF-4).
文摘Exploring low-cost and earth-abundant oxygen reduction reaction(ORR)electrocatalyst is essential for fuel cells and metal–air batteries.Among them,non-metal nanocarbon with multiple advantages of low cost,abundance,high conductivity,good durability,and competitive activity has attracted intense interest in recent years.The enhanced ORR activities of the nanocarbons are normally thought to originate from heteroatom(e.g.,N,B,P,or S)doping or various induced defects.However,in practice,carbon-based materials usually contain both dopants and defects.In this regard,in terms of the co-engineering of heteroatom doping and defect inducing,we present an overview of recent advances in developing non-metal carbon-based electrocatalysts for the ORR.The characteristics,ORR performance,and the related mechanism of these functionalized nanocarbons by heteroatom doping,defect inducing,and in particular their synergistic promotion effect are emphatically analyzed and discussed.Finally,the current issues and perspectives in developing carbon-based electrocatalysts from both of heteroatom doping and defect engineering are proposed.This review will be beneficial for the rational design and manufacturing of highly efficient carbon-based materials for electrocatalysis.
基金the National Natural Science Foundation of China(No.52102299)the Guangdong Basic and Applied Basic Research Foundation(Nos.2021A1515110059,2020A1515110250,and 2021B1515120041)+1 种基金the National Key Research and Development Program of China(No.2020YFA0715000)the Hainan Provincial Joint Project of Sanya Yazhou Bay Science and Technology City(Grant No.2021JJLH0058).
文摘Due to its abundant sodium content and low cost,sodium-ion battery(SIB)has become an effective substitute and supplement for lithium-ion batteries,which has a broad development prospect in largescale energy storage systems.Na-super-ionic conductor(NASICON)structural materials have stable 3D skeleton structures and open Na+transport channels,which is a very promising SIB cathode material.But in the typical NASICON material Na_(3)V_(2)(PO_(4))_(3)(NVP),the number of electrons involved in NVP per formula unit is less than 2 at the stable voltage window,which limits the further improvement of battery performance.In this work,we report another NASICON structured Na_(3)V_(4/3)Cr_(2/3)(PO_(4))_(3)@C(NVCP@C),which is obtained by Cr-doped NVP through spray drying.By taking full advantage of the voltage platforms of V^(5+/4+),V^(4+/3+),and V^(3+/2+)in the window of 1.5-4.4 V,NVCP@C delivered a high discharge capacity(175 mAh g^(-1))and durable cyclability(86%capacity retention for 2000 cycles).In-situ X-ray diffraction results demonstrate that the reversible structural evolution accompanies by solid-solution reaction and two-phase reaction mechanisms co-exist during charge/discharge processes.When coupled with Na^(+)preembedded hard carbon(HC),the assembled NVCP@C//HC full cell delivers a high capacity(105 mAh g^(-1))and long cycling performance(70%after 1000 cycles).This Cr-doped NVP method offers new insights into the design of high-energy NASICON-structured cathode materials.
基金financially sponsored by the National Natural Science Foundation of China(Grant No.22075223,22179104)the State Key Laboratory of Advanced Technology for Materials Synthesis and Processing(Wuhan University of Technology)(2021-ZD-4)the Fundamental Research Funds for the Central Universities(No.2020-YB-012)。
文摘The epitaxial heterostructure can be rationally designed based on the in situ growth of two compatible phases with lattice similarity,in which the modulated electronic states and tuned adsorption behaviors are conducive to the enhancement of electrocatalytic activity.Herein,theoretical simulations first disclose the charge transfer trend and reinforced inherent electron conduction around the epitaxial heterointerface between Ru clusters and Ni_(3)N substrate(cRu-Ni_(3)N),thus leading to the optimized adsorption behaviors and reduced activation energy barriers.Subsequently,the defectrich nanosheets with the epitaxially grown cRu-Ni_(3)N heterointerface are successfully constructed.Impressively,by virtue of the superiority of intrinsic activity and reaction kinetics,such unique epitaxial heterostructure exhibits remarkable bifunctional catalytic activity toward electrocatalytic OER(226 mV@20 mA cm^(−2))and HER(32 mV@10 mA cm^(−2))in alkaline media.Furthermore,it also shows great application prospect in alkaline freshwater and seawater splitting,as well as solar-to-hydrogen integrated system.This work could provide beneficial enlightenment for the establishment of advanced electrocatalysts with epitaxial heterointerfaces.
