To realize the application of electromagnetic wave absorption(EWA)devices in humid marine environments,bifunctional EWA materials with better EWA capacities and anticorrosion properties have great exploration signific...To realize the application of electromagnetic wave absorption(EWA)devices in humid marine environments,bifunctional EWA materials with better EWA capacities and anticorrosion properties have great exploration significance and systematic research re-quirements.By utilizing the low-cost and excellent magnetic and stable chemical characteristics of barium ferrite(BaFe_(12)O_(19))and using the high dielectric loss and excellent chemical inertia of nanocarbon clusters,a new type of nanocomposites with carbon nanoclusters en-capsulating BaFe_(12)O_(19)was designed and synthesized by combining an impregnation method and a high-temperature calcination strategy.Furthermore,Ce-Mn ions were introduced into the BaFe_(12)O_(19)lattice to improve the dielectric and magnetic properties of BaFe_(12)O_(19)cores significantly,and the energy band structure of the doped lattice and the orders of Ce replacing Fe sites were calculated.Benefiting from Ce-Mn ion doping and carbon nanocluster encapsulation,the composite material exhibited excellent dual functionality of corrosion resist-ance and EWA.When BaCe_(0.2)Mn_(0.3)Fe_(11.5)O_(19)-C(BCM-C)was calcined at 600°C,the minimum reflection loss of-20.1 dB was achieved at 14.43 GHz.The Ku band’s effective absorption bandwidth of 4.25 GHz was achieved at an absorber thickness of only 1.3 mm.The BCM-C/polydimethylsiloxane coating had excellent corrosion resistance in the simulated marine environment(3.5wt%NaCl solution).The|Z|0.01Hz value of BCM-C remained at 106Ω·cm^(2)after 12 soaking days.The successful preparation of the BaFe_(12)O_(19)composite en-capsulated with carbon nanoclusters provides new insights into the preparation of multifunctional absorbent materials and the fabrication of absorbent devices applied in humid marine environments in the future.展开更多
To address the challenges of air stability and slurry processability in layered transition metal oxide O_(3)-type NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(NFM)for sodium-ion batteries(SIBs),we have designed an innovative 500℃...To address the challenges of air stability and slurry processability in layered transition metal oxide O_(3)-type NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(NFM)for sodium-ion batteries(SIBs),we have designed an innovative 500℃reheating strategy.This method improves the surface properties of NFM without the need for additional coating layers,making it more efficient and suitable for large-scale applications.Pristine NFM(NFM-P)was first synthesized through a high-temperature solid-state method and then modified using this reheating approach(NFM-HT).This strategy significantly enhances air stability and electrochemical performance,yielding an initial discharge specific capacity of 151.46 mAh/g at 0.1C,with a remarkable capacity retention of 95.04%after 100 cycles at 0.5C.Additionally,a 1.7 Ah NFM‖HC(hard carbon)pouch cell demonstrates excellent long-term cycling stability(94.64%retention after 500 cycles at 1C),superior rate capability(86.48%retention at 9C),and strong low-temperature performance(77%retention at-25℃,continuing power supply at-40℃).Notably,even when overcharged to 8.29 V,the pouch cell remained safe without combustion or explosion.This reheating strategy,which eliminates the need for a coating layer,offers a simpler,more scalable solution for industrial production while maintaining outstanding electrochemical performance.These results pave the way for broader commercial adoption of NFM materials.展开更多
MAX series materials,as non-van der Waals layered multi-element compounds,contribute remarkable regulated properties and functional dimension,combining the features of metal and ceramic materials due to their inherent...MAX series materials,as non-van der Waals layered multi-element compounds,contribute remarkable regulated properties and functional dimension,combining the features of metal and ceramic materials due to their inherently laminated crystal structure that Mn+1Xn slabs are intercalated with A element layers.Oriented to the functional requirements of information,intelligence,electrification,and aerospace in the new era,how to accelerate MAX series materials into new quality productive forces?The systematic enhancement of knowledge about MAX series materials is intrinsic to understanding its low-dimensional geometric structure characteristics,and physical and chemical properties,revealing the correlation of composition,structure,and function and further realizing rational design based on simulation and prediction.Diversity also brings complexity to MAX materials research.This review provides substantial tabular information on(Ⅰ)MAX’s research timeline from 1960 to the present,(Ⅱ)structure diversity and classification convention,(Ⅲ)synthesis route exploration,(Ⅳ)prediction based on theory and machine learning,(Ⅴ)properties,and(Ⅵ)functional applications.Herein,the researchers can quickly locate research content and recognize connections and differences of MAX series materials.In addition,the research challenges for the future development of MAX series materials are highlighted.展开更多
Activities of space materials science research in China have been continuously supported by two main national programs.One is the China Space Station(CSS)program since 1992,and the other is the Strategic Priority Prog...Activities of space materials science research in China have been continuously supported by two main national programs.One is the China Space Station(CSS)program since 1992,and the other is the Strategic Priority Program(SPP)on Space Science since 2011.In CSS plan in 2019,eleven space materials science experimental projects were officially approved for execution during the construction of the space station.In the SPP Phase Ⅱ launched in 2018,seven pre-research projects are deployed as the first batch in 2018,and one concept study project in 2019.These pre-research projects will be cultivated as candidates for future selection as space experiment projects on the recovery of scientific experimental satellites in the future.A new apparatus of electrostatic levitation system for ground-based research of space materials science and rapid solidification research has been developed under the support of the National Natural Science Foundation of China.In order to promote domestic academic activities and to enhance the advancement of space materials science in China,the Space Materials Science and Technology Division belong to the Chinese Materials Research Society was established in 2019.We also organized scientists to write five review papers on space materials science as a special topic published in the journal Scientia Sinica to provide valuable scientific and technical references for Chinese researchers.展开更多
Refractory high/medium-entropy alloys(RH/MEAs)are known for their outstanding performance at el-evated temperatures;however,they usually exhibit poor room-temperature plasticity,which can be at-tributed to the non-uni...Refractory high/medium-entropy alloys(RH/MEAs)are known for their outstanding performance at el-evated temperatures;however,they usually exhibit poor room-temperature plasticity,which can be at-tributed to the non-uniform deformation that occurs at room temperature.Once cracks nucleate,they will rapidly propagate into vertical splitting cracks.Here,we introduce multiple phases including FCC and HCP phases into the NbMoTa RMEA via appropriate addition of carbon.The results show that multiple-phase synergy effectively suppresses non-uniform deformation,thereby delaying the onset of vertical splitting cracks.An optimal combination of compressive strength-plasticity is achieved by the(NbMoTa)_(92.5)C_(7.5) alloy.The significant improvement in room-temperature mechanical properties can be attributed to its hierarchical microstructure:in the mesoscale,the BCC matrix is divided by eutectic structures;while at the microscale,the BCC matrix is further refined by abundant lath-like FCC precipitates.The FCC precip-itates contain high-density stacking faults,acting as a dislocation source under compressive loading.The HCP phase in the eutectic microstructures,in turn,acts as a strong barrier to dislocation movement and simultaneously increases the dislocation storage capacity.These findings open a new route to tailor the microstructure and mechanical properties of RH/MEAs.展开更多
Rolling contact fatigue performance is among the most important issues for applications of bearing steels.In this work,a recently developed surface modification technique,surface mechanical rolling treatment,was appli...Rolling contact fatigue performance is among the most important issues for applications of bearing steels.In this work,a recently developed surface modification technique,surface mechanical rolling treatment,was applied on a rare-earth addition bearing steel.And rolling contact fatigue behavior of treated samples was compared with that of as-received counterparts at different contacting stresses.The results demonstrated that a 700μm-thick gradient nanostructured surface layer is produced on samples by surface mechanical rolling treatment.The grain size decreases while the microhardness increases gradually with decreasing depth,reaching~23 nm and~10.2 GPa,respectively,at the top surface.Consequently,the rolling contact fatigue property is significantly enhanced.The characteristic life of treated samples is~3.2 times that of untreated counterparts according to Weibull curves at 5.6 GPa.Analyses of fatigue mechanisms demonstrated that the gradient nanostructured surface layer might not only retard material degradation and microcrack formation,but also prolong the steady-state elastic response stage under rolling contact fatigue.展开更多
Solid-state electrolytes(SSEs),as the core component within the next generation of key energy storage technologies-solid-state lithium batteries(SSLBs)-are significantly leading the development of future energy storag...Solid-state electrolytes(SSEs),as the core component within the next generation of key energy storage technologies-solid-state lithium batteries(SSLBs)-are significantly leading the development of future energy storage systems.Among the numerous types of SSEs,inorganic oxide garnet-structured superionic conductors Li7La3Zr2O12(LLZO)crystallized with the cubic Iaˉ3d space group have received considerable attention owing to their highly advantageous intrinsic properties encompassing reasonable lithium-ion conductivity,wide electrochemical voltage window,high shear modulus,and excellent chemical stability with electrodes.However,no SSEs possess all the properties necessary for SSLBs,thus both the ionic conductivity at room temperature and stability in ambient air regarding cubic garnet-based electrolytes are still subject to further improvement.Hence,this review comprehensively covers the nine key structural factors affecting the ion conductivity of garnet-based electrolytes comprising Li concentration,Li vacancy concentration,Li carrier concentration and mobility,Li occupancy at available sites,lattice constant,triangle bottleneck size,oxygen vacancy defects,and Li-O bonding interactions.Furthermore,the general illustration of structures and fundamental features being crucial to chemical stability is examined,including Li concentration,Li-site occupation behavior,and Li-O bonding interactions.Insights into the composition-structure-property relations among cubic garnet-based oxide ionic conductors from the perspective of their crystal structures,revealing the potential compatibility conflicts between ionic transportation and chemical stability resulting from Li-O bonding interactions.We believe that this review will lay the foundation for future reasonable structural design of oxide-based or even other types of superionic conductors,thus assisting in promoting the rapid development of alternative green and sustainable technologies.展开更多
Quantitative detection of trace small-sized nanoplastics(<100 nm)remains a significant challenge in surface-enhanced Raman scattering(SERS).To tackle this issue,we developed a hydrophobic CuO@Ag nanowire substrate ...Quantitative detection of trace small-sized nanoplastics(<100 nm)remains a significant challenge in surface-enhanced Raman scattering(SERS).To tackle this issue,we developed a hydrophobic CuO@Ag nanowire substrate and introduced a multiplex-feature analysis strategy based on the coffee ring effect.This substrate not only offers high Raman enhancement but also exhibits a high probability of detection(POD),enabling rapid and accurate identification of 50 nm polystyrene nanoplastics over a broad concentration range(1–10−10 wt%).Importantly,experimental results reveal a strong correlation between the coffee ring formation and the concentration of nanoplastic dispersion.By incorporating Raman signal intensity,coffee ring diameter,and POD as combined features,we established a machine learning-based mapping between nanoplastic concentration and coffee ring characteristics,allowing precise predictions of dispersion concentration.The mean squared error of these predictions is remarkably low,ranging from 0.21 to 0.54,representing a 19 fold improvement in accuracy compared to traditional linear regression-based methods.This strategy effectively integrates SERS with wettability modification techniques,ensuring high sensitivity and fingerprinting capabilities,while addressing the limitations of Raman signal intensity in accurately reflecting concentration changes at ultra-low levels,providing a new idea for precise SERS measurements of nanoplastics.展开更多
Electrocatalytic CO_(2)reduction(ECR)to produce value-added fuels and chemicals using renewable electricity is an emerging strategy to mitigate global warming and decrease reliance on fossil fuels.Among various ECR pr...Electrocatalytic CO_(2)reduction(ECR)to produce value-added fuels and chemicals using renewable electricity is an emerging strategy to mitigate global warming and decrease reliance on fossil fuels.Among various ECR products,liquid oxygenates(Oxys)are especially attractive due to their high energy density,high safety and transportability that could be adapted to the existing infrastructure and transportation system.However,efficiently generating these highly reduced oxygen-containing products by ECR remains challenging due to the complexity of coupled proton and electron transfer processes.In recent years,in-depth studies of reaction mechanisms have advanced the design of catalysts and the regulation of reaction systems for ECR to produce Oxys,Here,by focusing on the production of typical Oxys,such as methanol,acetic acid,ethanol,acetone,n-propanol,and isopropanol,we outline various reaction paths and key intermediates for the electrochemical conversion of CO_(2)into these target products.We also summarize the current research status and recent advances in catalysts based on their elemental composition,and consider recent studies on the change of catalyst geometry and electronic structure,as well as the optimization of reaction systems to increase ECR performance.Finally,we analyze the challenges in the field of ECR to Oxys and provide an outlook on future directions for high-efficiency catalyst prediction and design,as well as the development of advanced reaction systems.展开更多
The single-layer Ti_(3)C_(2)T_(x)/MXene has become a special electromagnetic wave absorber near the terahertz band because of its abundant surface groups and excellent conductivity.However,the macro-preparation of sin...The single-layer Ti_(3)C_(2)T_(x)/MXene has become a special electromagnetic wave absorber near the terahertz band because of its abundant surface groups and excellent conductivity.However,the macro-preparation of single-layer Ti_(3)C_(2)T_(x)/MXene shows significantly difficult to influence its application.The two-dimensional Ti_(3)C_(2)T_(x)is easily prepared to have high production,but its weak absorption ability due to high surface conductivity also restricts its application.To realize the strong electromagnetic wave absorption of two-dimensional Ti_(3)C_(2)T_(x)/MXene,a new strategy with magnetic FeNi nanoparticles decorating Ti_(3)C_(2)T_(x)/MXene composites(FeNi-Ti_(3)C_(2)T_(x))were proposed and the effective electromagnetic wave absorption features covering 170-220 GHz that means the absorption band width reach 50 GHz.With an absorber composite film thickness being only 0.6 mm,the absorptivity of the composite is enhanced with the increase of decorating FeNi nanoparticles and promote up to 75%when the FeNi nanoparticles loading content reaches 30 wt%.The improvement of absorption is attributed to the introduction of soft magnetic FeNi to adjust the high surface conductivity of MXene and improve the electromagnetic balance of the absorber.展开更多
The use of lithium-sulfur(Li-S)batteries is limited by sulfur redox reactions involving multi-phase transformations,especially at low-temperatures.To address this issue,we report a material(FCNS@NCFs)consisting of nit...The use of lithium-sulfur(Li-S)batteries is limited by sulfur redox reactions involving multi-phase transformations,especially at low-temperatures.To address this issue,we report a material(FCNS@NCFs)consisting of nitrogen-doped carbon fibers loaded with a ternary metal sulf-ide((Fe,Co,Ni)_(9)S_(8))for use as the sulfur host in Li-S batteries.This materi-al was prepared using transfer blot filter paper as the carbon precursor,thiourea as the source of nitrogen and sulfur,and FeCl_(3)·6H_(2)O,CoCl_(2)·6H_(2)O and NiCl_(2)·6H_(2)O as the metal ion sources.It was synthesized by an impreg-nation method followed by calcination.The nitrogen doping significantly in-creased the conductivity of the host,and the metal sulfides have excellent catalytic activities.Theoretical calculations,and adsorption and deposition experiments show that active sites on the surface of FCNS@NCFs selectively adsorb polysulfides,facilitate rapid adsorption and conversion,prevent cathode passivation and inhib-it the polysulfide shuttling.The FCNS@NCFs used as the sulfur host has excellent electrochemical properties.Its initial dis-charge capacity is 1639.0 mAh g^(−1) at 0.2 C and room temperature,and it remains a capacity of 1255.1 mAh g^(−1) after 100 cycles.At−20~C,it has an initial discharge capacity of 1578.5 mAh g^(−1) at 0.2 C,with a capacity of 867.5 mAh g^(−1) after 100 cycles.Its excellent performance at both ambient and low temperatures suggests a new way to produce high-performance low-temper-ature Li-S batteries.展开更多
Mullite has a high melting point,high hardness,good thermal shock resistance,corrosion resistance,and high-temperature mechanical properties.Mullite raw materials are mostly synthesized by the sintering method and ele...Mullite has a high melting point,high hardness,good thermal shock resistance,corrosion resistance,and high-temperature mechanical properties.Mullite raw materials are mostly synthesized by the sintering method and electric fused method.The research and application progress of pure mullite and its composite refractories in fields such as ceramics,metallurgy,aerospace,military industry,cement and glass were reviewed.The future development trend of mullite in the application of refractories was prospected.展开更多
The microstructures and corrosion behavior of 1.0wt%Gd-containing neutron-absorbing duplex stainless steel annealed at different temperatures were studied.Results reveal that the content of Gd-containing secondary pha...The microstructures and corrosion behavior of 1.0wt%Gd-containing neutron-absorbing duplex stainless steel annealed at different temperatures were studied.Results reveal that the content of Gd-containing secondary phase increases with increasing the annealing temperatures to 1080℃,and then decreases.In the sample annealed at 1080℃,M-Gd(M=Fe,Cr,Ni)intermetallic with M_(3)Gd as the core phase and M_(12)Gd as the shell is the primary secondary phase.In the sample annealed at 1140℃,M_(3)Gd phase is dominant.The corrosion behavior of the two annealed steel samples were analyzed in NaCl,HCl and H_(3)BO_(3) solutions.It is found that the sample annealed at 1140℃ has lower corrosion rate.M_(3)Gd is more electrochemically active than M_(12)Gd when the sample is immersed in NaCl and HCl solutions,but more noble in H_(3)BO_(3) solution.展开更多
Mg_(3)Bi_(2)-based flms are promising near-room-temperature thermoelectric materials for the development of fexible thermoelectric devices.However,the high hole concentration caused by the abundance of intrinsic Mg va...Mg_(3)Bi_(2)-based flms are promising near-room-temperature thermoelectric materials for the development of fexible thermoelectric devices.However,the high hole concentration caused by the abundance of intrinsic Mg vacancies easily leads to deterioration of electrical properties,especially for p-type Mg_(3)Bi_(2) flm.And the optimization of thermal conductivity of the Mg_(3)Bi_(2)-based flms is barely investigated.In this work,we demonstrate the improved thermoelectric performances of p-type Mg_(3)Bi_(2) through Ag doping by magnetron sputtering.This doping successfully reduces the hole concentration and broadens the band gap of Mg_(3)Bi_(2),thus resulting in a peak power factor of 442μW m−1 K−2 at 525 K.At the same time,Ag doping-induced fuctuations in mass and microscopic strain efectively enhanced the phonon scattering to reduce the lattice thermal conductivity.Consequently,a maximum thermoelectric fgure of merit of 0.22 is achieved at 525 K.Its near-roomtemperature thermoelectric performances demonstrate superior performance compared to many Mg_(3)Bi_(2)-based flms.To further evaluate its potential for thermoelectric power generation,we fabricated a thermoelectric device using Ag-doped Mg_(3)Bi_(2) flms,which achieved a power density of 864μW cm⁻2 at 35 K temperature diference.This study presents an efective strategy for the advancement of Mg_(3)Bi_(2)-based flms for application in micro-thermoelectric devices.展开更多
Organic-inorganic hybrid solar cells consisting of organic conjugated materials and inorganic quantum dots(QDs)have been of great interest during the past two decades.However,it is still challenging to select desired ...Organic-inorganic hybrid solar cells consisting of organic conjugated materials and inorganic quantum dots(QDs)have been of great interest during the past two decades.However,it is still challenging to select desired organic functional materials for fabricating hybrid films to maximize their photovoltaic performance.Herein,we report the synthesis of three narrow bandgap non-fullerene conjugated polymers and further demonstrate the importance and impact of polymer crystallinity in tuning the organic-inorganic hybrid interface towards improved photovoltaic performance.In specific,we develop an organic-inorganic hybrid active layer using a newly synthesized polymer with relatively weaker crystallinity and FAPbI_(3)QDs,enabling complementary absorption and favorable interface/morphology for efficient charge separation and transport.The champion PCDOT-T/FAPbI_(3)QD hybrid device achieves a record-high efficiency of 13.11%based on the one-step coating organic/QD hybrid bulk heterojunction blend,which is significantly improved relative to the semi-crystalline polymer PYIT-based hybrid device(11.23%)and pristine QD(10.51%).We believe these findings would provide new insight into the organic/QD interface to construct desired hybrid films for high-performing optoelectronic applications.展开更多
Simultaneously improving the strength and electrical conductivity of conducting metallic materials is of great significance,but it still remains a key challenge as the two properties are often mutually exclusive.In th...Simultaneously improving the strength and electrical conductivity of conducting metallic materials is of great significance,but it still remains a key challenge as the two properties are often mutually exclusive.In this study,we demonstrate a“<111>oriented fibrous grains with ultra-high aspect ratio”strategy for breaking such a conflict in Cu wire,which relies on the distinctive spatial distribution of grain boundaries and the highly consistent hard orientation to play their respective roles in suffering loading and conducting,thereby enabling a separate optimization of both strength and electrical conductivity.Therefore,a processing route was designed,involving directional solidification followed by large drawing deformation,to successfully construct fibrous grains with an ultra-high aspect ratio in 596.7 and ultra-high<111>texture proportion over 97%,which achieves Cu wire with a remarkable combination of yield strength in 482.3 MPa and electrical conductivity in 101.63%IACS.Finally,the mechanisms for high strength and high electrical conductivity were quantitatively discussed.展开更多
In the present study,a simple but effective two-step annealing processing strategy via manipulating the austenite reversion path is proposed to obtain a large fraction of retained austenite in low-Mn medium-Mn steels....In the present study,a simple but effective two-step annealing processing strategy via manipulating the austenite reversion path is proposed to obtain a large fraction of retained austenite in low-Mn medium-Mn steels.Initially,the Fe-3Mn-0.2C-1.5Si(wt%)steel is intercritically annealed to form Mn-enriched lamellar martensite precursors.Subsequently,the austenite reversion transformation is manipulated to occur within the martensite lamellae during the second annealing process,resulting in an ultra-fine duplex microstructure of laminated austenite and ferrite.This process can not only allow a large fraction of austenite to be retained in low-Mn medium-Mn steels,but also increase the elongation by up to 41%without sacrificing the strength level compared to the conventional annealing.展开更多
Precipitation-strengthened HEAs exhibit outstanding integration of strength and toughness at ambient temperature.Nevertheless,precipitates generally reduce the localized corrosion resistance in aggressive solution env...Precipitation-strengthened HEAs exhibit outstanding integration of strength and toughness at ambient temperature.Nevertheless,precipitates generally reduce the localized corrosion resistance in aggressive solution environments.To solve this problem,a strategy of introducing nano-sized L12 precipitates in CoCrFeNiAlTi HEAs has been proposed in this work.Results demonstrate the pitting corrosion potential can be elevated from 258 mVSCE to 603 mVSCE by increasing the precipitate content to 38 wt.%.Such an improvement in localized corrosion resistance can be attributed to two aspects.Firstly,L12 precipitates tend to be dissolved during the corrosion process,which promotes the heterogeneous nucleation of protective Cr2 O3 due to the rapid deposition of oxides/hydroxides of Al/Ti,and improves the passive film stability due to the Crrich FCC matrix.Secondly,the dissolution kinetic inside the pits can be suppressed on account of the enrichment of Cr element in the FCC matrix,thus inhibiting the pitting growth.In summary,the current work not only reveals the mechanisms of the nano-sized L12 precipitates upon the corrosion behavior,but also provides a strategy for designing corrosion-resistant HEA.展开更多
A principle was proposed for designing a method to seal anodized aluminum used in semiconductor processing apparatuses.Thermodynamic calculations and Fick’s second law were used to reveal trends in the metal ion depo...A principle was proposed for designing a method to seal anodized aluminum used in semiconductor processing apparatuses.Thermodynamic calculations and Fick’s second law were used to reveal trends in the metal ion deposition,deposition product stability,vapor pressures of halides for selected metal ions,the holding temperature,and time.Interactions between ion concentrations and the sealing temperature were also revealed.According to the design principles,anodized aluminum dipped in 1 mM Cr^(3+)ion solution and steam-sealed for 18 h exhibited the highest corrosion resistance when exposed to 5 wt.%HCl solution and HCl gas,verifying the designed results.展开更多
Intermetallic Pt-based nanoparticles have displayed excellent activity for the oxygen reduction reaction(ORR)in fuel cells.However,it remains a great challenge to synthesize highly atomically ordered Pt-based nanopart...Intermetallic Pt-based nanoparticles have displayed excellent activity for the oxygen reduction reaction(ORR)in fuel cells.However,it remains a great challenge to synthesize highly atomically ordered Pt-based nanoparticle catalysts because the formation of an atomically ordered structure usually requires high-temperature annealing accompanied by grain sintering.Here we report the direct epitaxial growth of well-aligned,highly atomically ordered Pt3 Fe and PtFe nanoparticles(<5 nm)on single-walled carbon nanotube(SWCNT)bundles films.The long-range periodically symmetric van der Waals(vdW)interac-tions between SWCNT bundles and Pt-Fe nanoparticles play an important role in promoting not only the alignment ordering of inter-nanoparticles but also the atomic ordering of intra-nanoparticles.The ordered Pt_(3)Fe/SWCNT catalyst showed enhanced ORR catalytic performance of 2.3-fold higher mass activity and 3.1-fold higher specific activity than commercial Pt/C.Moreover,the formation of an interlocked inter-face and strong vdW interaction endow the Pt-Fe/SWCNT catalysts with extreme long-term stability in potential cycling and excellent anti-thermal sintering ability.展开更多
基金supported by the National Key R&D Program of China(Nos.2022YFB3504804 and 2023YFF0718303)the National Natural Science Foundation of China(Nos.51871219,52071324,52031014,and 52401255)+1 种基金Science and Technology Project of Shenyang City(No.22-101-0-27)Liaoning Institute of Science and Technology Doctoral Initiation Fund Project(No.2307B19).
文摘To realize the application of electromagnetic wave absorption(EWA)devices in humid marine environments,bifunctional EWA materials with better EWA capacities and anticorrosion properties have great exploration significance and systematic research re-quirements.By utilizing the low-cost and excellent magnetic and stable chemical characteristics of barium ferrite(BaFe_(12)O_(19))and using the high dielectric loss and excellent chemical inertia of nanocarbon clusters,a new type of nanocomposites with carbon nanoclusters en-capsulating BaFe_(12)O_(19)was designed and synthesized by combining an impregnation method and a high-temperature calcination strategy.Furthermore,Ce-Mn ions were introduced into the BaFe_(12)O_(19)lattice to improve the dielectric and magnetic properties of BaFe_(12)O_(19)cores significantly,and the energy band structure of the doped lattice and the orders of Ce replacing Fe sites were calculated.Benefiting from Ce-Mn ion doping and carbon nanocluster encapsulation,the composite material exhibited excellent dual functionality of corrosion resist-ance and EWA.When BaCe_(0.2)Mn_(0.3)Fe_(11.5)O_(19)-C(BCM-C)was calcined at 600°C,the minimum reflection loss of-20.1 dB was achieved at 14.43 GHz.The Ku band’s effective absorption bandwidth of 4.25 GHz was achieved at an absorber thickness of only 1.3 mm.The BCM-C/polydimethylsiloxane coating had excellent corrosion resistance in the simulated marine environment(3.5wt%NaCl solution).The|Z|0.01Hz value of BCM-C remained at 106Ω·cm^(2)after 12 soaking days.The successful preparation of the BaFe_(12)O_(19)composite en-capsulated with carbon nanoclusters provides new insights into the preparation of multifunctional absorbent materials and the fabrication of absorbent devices applied in humid marine environments in the future.
基金the financial support provided by the Longzihu New Energy Laboratory Joint Fund of Henan Province(2023008)the Energy Storage Mater.and Processes Key Laboratory of Henan Province Open Fund(2021003)+1 种基金the Collaborative Innovation Team Project Fund of Industry-University-Research(32214085)the financial support received from Zhejiang Vast Na Technology Co.,Ltd.(24110380)。
文摘To address the challenges of air stability and slurry processability in layered transition metal oxide O_(3)-type NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(NFM)for sodium-ion batteries(SIBs),we have designed an innovative 500℃reheating strategy.This method improves the surface properties of NFM without the need for additional coating layers,making it more efficient and suitable for large-scale applications.Pristine NFM(NFM-P)was first synthesized through a high-temperature solid-state method and then modified using this reheating approach(NFM-HT).This strategy significantly enhances air stability and electrochemical performance,yielding an initial discharge specific capacity of 151.46 mAh/g at 0.1C,with a remarkable capacity retention of 95.04%after 100 cycles at 0.5C.Additionally,a 1.7 Ah NFM‖HC(hard carbon)pouch cell demonstrates excellent long-term cycling stability(94.64%retention after 500 cycles at 1C),superior rate capability(86.48%retention at 9C),and strong low-temperature performance(77%retention at-25℃,continuing power supply at-40℃).Notably,even when overcharged to 8.29 V,the pouch cell remained safe without combustion or explosion.This reheating strategy,which eliminates the need for a coating layer,offers a simpler,more scalable solution for industrial production while maintaining outstanding electrochemical performance.These results pave the way for broader commercial adoption of NFM materials.
基金financial support by the Development Plan of Science and Technology of Jilin Province(No.YDZJ202201ZYTS305)the Natural Science Foundation of Jilin Province(No.YDZJ202401316ZYTS)the Innovation Laboratory Development Program of Education Department of Jilin Province and Industry and Information Technology Department of Jilin Province,China(The Joint Laboratory of MAX/MXene Materials).
文摘MAX series materials,as non-van der Waals layered multi-element compounds,contribute remarkable regulated properties and functional dimension,combining the features of metal and ceramic materials due to their inherently laminated crystal structure that Mn+1Xn slabs are intercalated with A element layers.Oriented to the functional requirements of information,intelligence,electrification,and aerospace in the new era,how to accelerate MAX series materials into new quality productive forces?The systematic enhancement of knowledge about MAX series materials is intrinsic to understanding its low-dimensional geometric structure characteristics,and physical and chemical properties,revealing the correlation of composition,structure,and function and further realizing rational design based on simulation and prediction.Diversity also brings complexity to MAX materials research.This review provides substantial tabular information on(Ⅰ)MAX’s research timeline from 1960 to the present,(Ⅱ)structure diversity and classification convention,(Ⅲ)synthesis route exploration,(Ⅳ)prediction based on theory and machine learning,(Ⅴ)properties,and(Ⅵ)functional applications.Herein,the researchers can quickly locate research content and recognize connections and differences of MAX series materials.In addition,the research challenges for the future development of MAX series materials are highlighted.
基金Supports by the Strategic Priority Research Program on Space Science,the Chinese Academy of Sciences(XDA15013200,XDA15013700,XDA15013800,XDA15051200)the China’s Manned Space Station Project(TGJZ800-2-RW024)and the National Natural Science Foundation of China(51327901)。
文摘Activities of space materials science research in China have been continuously supported by two main national programs.One is the China Space Station(CSS)program since 1992,and the other is the Strategic Priority Program(SPP)on Space Science since 2011.In CSS plan in 2019,eleven space materials science experimental projects were officially approved for execution during the construction of the space station.In the SPP Phase Ⅱ launched in 2018,seven pre-research projects are deployed as the first batch in 2018,and one concept study project in 2019.These pre-research projects will be cultivated as candidates for future selection as space experiment projects on the recovery of scientific experimental satellites in the future.A new apparatus of electrostatic levitation system for ground-based research of space materials science and rapid solidification research has been developed under the support of the National Natural Science Foundation of China.In order to promote domestic academic activities and to enhance the advancement of space materials science in China,the Space Materials Science and Technology Division belong to the Chinese Materials Research Society was established in 2019.We also organized scientists to write five review papers on space materials science as a special topic published in the journal Scientia Sinica to provide valuable scientific and technical references for Chinese researchers.
基金financial support from the Na-tional Natural Science Foundation of China(No.52231006)National Key Research and Development Program of China(No.2017YFB0702003)the National Natural Science Foundation of China(No.51871217).
文摘Refractory high/medium-entropy alloys(RH/MEAs)are known for their outstanding performance at el-evated temperatures;however,they usually exhibit poor room-temperature plasticity,which can be at-tributed to the non-uniform deformation that occurs at room temperature.Once cracks nucleate,they will rapidly propagate into vertical splitting cracks.Here,we introduce multiple phases including FCC and HCP phases into the NbMoTa RMEA via appropriate addition of carbon.The results show that multiple-phase synergy effectively suppresses non-uniform deformation,thereby delaying the onset of vertical splitting cracks.An optimal combination of compressive strength-plasticity is achieved by the(NbMoTa)_(92.5)C_(7.5) alloy.The significant improvement in room-temperature mechanical properties can be attributed to its hierarchical microstructure:in the mesoscale,the BCC matrix is divided by eutectic structures;while at the microscale,the BCC matrix is further refined by abundant lath-like FCC precipitates.The FCC precip-itates contain high-density stacking faults,acting as a dislocation source under compressive loading.The HCP phase in the eutectic microstructures,in turn,acts as a strong barrier to dislocation movement and simultaneously increases the dislocation storage capacity.These findings open a new route to tailor the microstructure and mechanical properties of RH/MEAs.
基金The financial supports by the Chinese Academy of Sciences(Nos.XDC04030300 and XDB0510303)CAS-HK Joint Laboratory of Nanomaterials and MechanicsShenyang National Laboratory for Materials Science are acknowledged.
文摘Rolling contact fatigue performance is among the most important issues for applications of bearing steels.In this work,a recently developed surface modification technique,surface mechanical rolling treatment,was applied on a rare-earth addition bearing steel.And rolling contact fatigue behavior of treated samples was compared with that of as-received counterparts at different contacting stresses.The results demonstrated that a 700μm-thick gradient nanostructured surface layer is produced on samples by surface mechanical rolling treatment.The grain size decreases while the microhardness increases gradually with decreasing depth,reaching~23 nm and~10.2 GPa,respectively,at the top surface.Consequently,the rolling contact fatigue property is significantly enhanced.The characteristic life of treated samples is~3.2 times that of untreated counterparts according to Weibull curves at 5.6 GPa.Analyses of fatigue mechanisms demonstrated that the gradient nanostructured surface layer might not only retard material degradation and microcrack formation,but also prolong the steady-state elastic response stage under rolling contact fatigue.
基金supported by the National Natural Science Foundation of China(Nos.22171102 and 22090044)the National Key R&D Program of China(Nos.2021YFF0500502 and 2023YFA1506304)+2 种基金the Jilin Province Science and Technology Development Plan(No.20230101024JC)the"Medicine+X"crossinnovation team of Bethune Medical Department of Jilin University"Leading the Charge with Open Competition"construction project(No.2022JBGS04)the Jilin University Graduate Training Office(Nos.2021JGZ08 and 2022YJSJIP20).
文摘Solid-state electrolytes(SSEs),as the core component within the next generation of key energy storage technologies-solid-state lithium batteries(SSLBs)-are significantly leading the development of future energy storage systems.Among the numerous types of SSEs,inorganic oxide garnet-structured superionic conductors Li7La3Zr2O12(LLZO)crystallized with the cubic Iaˉ3d space group have received considerable attention owing to their highly advantageous intrinsic properties encompassing reasonable lithium-ion conductivity,wide electrochemical voltage window,high shear modulus,and excellent chemical stability with electrodes.However,no SSEs possess all the properties necessary for SSLBs,thus both the ionic conductivity at room temperature and stability in ambient air regarding cubic garnet-based electrolytes are still subject to further improvement.Hence,this review comprehensively covers the nine key structural factors affecting the ion conductivity of garnet-based electrolytes comprising Li concentration,Li vacancy concentration,Li carrier concentration and mobility,Li occupancy at available sites,lattice constant,triangle bottleneck size,oxygen vacancy defects,and Li-O bonding interactions.Furthermore,the general illustration of structures and fundamental features being crucial to chemical stability is examined,including Li concentration,Li-site occupation behavior,and Li-O bonding interactions.Insights into the composition-structure-property relations among cubic garnet-based oxide ionic conductors from the perspective of their crystal structures,revealing the potential compatibility conflicts between ionic transportation and chemical stability resulting from Li-O bonding interactions.We believe that this review will lay the foundation for future reasonable structural design of oxide-based or even other types of superionic conductors,thus assisting in promoting the rapid development of alternative green and sustainable technologies.
基金the National Natural Science Foundation of China(No.12174229 and 22375117)Natural Science Foundation of Shandong Province(No.ZR2022YQ02 and ZR2023MB149)Taishan Scholars Program of Shandong Province(No.tsqn202306152)for financial support.
文摘Quantitative detection of trace small-sized nanoplastics(<100 nm)remains a significant challenge in surface-enhanced Raman scattering(SERS).To tackle this issue,we developed a hydrophobic CuO@Ag nanowire substrate and introduced a multiplex-feature analysis strategy based on the coffee ring effect.This substrate not only offers high Raman enhancement but also exhibits a high probability of detection(POD),enabling rapid and accurate identification of 50 nm polystyrene nanoplastics over a broad concentration range(1–10−10 wt%).Importantly,experimental results reveal a strong correlation between the coffee ring formation and the concentration of nanoplastic dispersion.By incorporating Raman signal intensity,coffee ring diameter,and POD as combined features,we established a machine learning-based mapping between nanoplastic concentration and coffee ring characteristics,allowing precise predictions of dispersion concentration.The mean squared error of these predictions is remarkably low,ranging from 0.21 to 0.54,representing a 19 fold improvement in accuracy compared to traditional linear regression-based methods.This strategy effectively integrates SERS with wettability modification techniques,ensuring high sensitivity and fingerprinting capabilities,while addressing the limitations of Raman signal intensity in accurately reflecting concentration changes at ultra-low levels,providing a new idea for precise SERS measurements of nanoplastics.
基金financial supports from the National Natural Science Foundation of China(52201237)the Talent Introduction Project of Chinese Academy of Sciences(E344011)+4 种基金the Shenzhen High Level Talent Team Project(KQTD2022110109364705)the Joint Research Project of China Merchants Group and SIAT(E2Z1521)the Cross Institute Joint Research Youth Team Project of SIAT(E25427)National Natural Science Foundation of China(52402136)the China Postdoctoral Science Foundation(E325281005)。
文摘Electrocatalytic CO_(2)reduction(ECR)to produce value-added fuels and chemicals using renewable electricity is an emerging strategy to mitigate global warming and decrease reliance on fossil fuels.Among various ECR products,liquid oxygenates(Oxys)are especially attractive due to their high energy density,high safety and transportability that could be adapted to the existing infrastructure and transportation system.However,efficiently generating these highly reduced oxygen-containing products by ECR remains challenging due to the complexity of coupled proton and electron transfer processes.In recent years,in-depth studies of reaction mechanisms have advanced the design of catalysts and the regulation of reaction systems for ECR to produce Oxys,Here,by focusing on the production of typical Oxys,such as methanol,acetic acid,ethanol,acetone,n-propanol,and isopropanol,we outline various reaction paths and key intermediates for the electrochemical conversion of CO_(2)into these target products.We also summarize the current research status and recent advances in catalysts based on their elemental composition,and consider recent studies on the change of catalyst geometry and electronic structure,as well as the optimization of reaction systems to increase ECR performance.Finally,we analyze the challenges in the field of ECR to Oxys and provide an outlook on future directions for high-efficiency catalyst prediction and design,as well as the development of advanced reaction systems.
基金supported by the National Key R&D Program of China(Nos.2023YFF0718303 and 2022YFB3504804)the National Natural Science Foundation of China(Nos.51871219,52031014 and 52401255)the Science and Technology Project of Shenyang City(No.22-101-0-27).
文摘The single-layer Ti_(3)C_(2)T_(x)/MXene has become a special electromagnetic wave absorber near the terahertz band because of its abundant surface groups and excellent conductivity.However,the macro-preparation of single-layer Ti_(3)C_(2)T_(x)/MXene shows significantly difficult to influence its application.The two-dimensional Ti_(3)C_(2)T_(x)is easily prepared to have high production,but its weak absorption ability due to high surface conductivity also restricts its application.To realize the strong electromagnetic wave absorption of two-dimensional Ti_(3)C_(2)T_(x)/MXene,a new strategy with magnetic FeNi nanoparticles decorating Ti_(3)C_(2)T_(x)/MXene composites(FeNi-Ti_(3)C_(2)T_(x))were proposed and the effective electromagnetic wave absorption features covering 170-220 GHz that means the absorption band width reach 50 GHz.With an absorber composite film thickness being only 0.6 mm,the absorptivity of the composite is enhanced with the increase of decorating FeNi nanoparticles and promote up to 75%when the FeNi nanoparticles loading content reaches 30 wt%.The improvement of absorption is attributed to the introduction of soft magnetic FeNi to adjust the high surface conductivity of MXene and improve the electromagnetic balance of the absorber.
基金partially supported by National Natural Science Foundation of China(52172250)Institute of Process Engineering(IPE)Project for Frontier Basic Research(QYJC-2023-06)。
文摘The use of lithium-sulfur(Li-S)batteries is limited by sulfur redox reactions involving multi-phase transformations,especially at low-temperatures.To address this issue,we report a material(FCNS@NCFs)consisting of nitrogen-doped carbon fibers loaded with a ternary metal sulf-ide((Fe,Co,Ni)_(9)S_(8))for use as the sulfur host in Li-S batteries.This materi-al was prepared using transfer blot filter paper as the carbon precursor,thiourea as the source of nitrogen and sulfur,and FeCl_(3)·6H_(2)O,CoCl_(2)·6H_(2)O and NiCl_(2)·6H_(2)O as the metal ion sources.It was synthesized by an impreg-nation method followed by calcination.The nitrogen doping significantly in-creased the conductivity of the host,and the metal sulfides have excellent catalytic activities.Theoretical calculations,and adsorption and deposition experiments show that active sites on the surface of FCNS@NCFs selectively adsorb polysulfides,facilitate rapid adsorption and conversion,prevent cathode passivation and inhib-it the polysulfide shuttling.The FCNS@NCFs used as the sulfur host has excellent electrochemical properties.Its initial dis-charge capacity is 1639.0 mAh g^(−1) at 0.2 C and room temperature,and it remains a capacity of 1255.1 mAh g^(−1) after 100 cycles.At−20~C,it has an initial discharge capacity of 1578.5 mAh g^(−1) at 0.2 C,with a capacity of 867.5 mAh g^(−1) after 100 cycles.Its excellent performance at both ambient and low temperatures suggests a new way to produce high-performance low-temper-ature Li-S batteries.
基金supported by the Starting Grants of Institute of Metal Research,Chinese Academy of Science(E255L401).
文摘Mullite has a high melting point,high hardness,good thermal shock resistance,corrosion resistance,and high-temperature mechanical properties.Mullite raw materials are mostly synthesized by the sintering method and electric fused method.The research and application progress of pure mullite and its composite refractories in fields such as ceramics,metallurgy,aerospace,military industry,cement and glass were reviewed.The future development trend of mullite in the application of refractories was prospected.
基金Research Foundation of Shenyang National Laboratory for Materials Science(L2019F15)Ling Chuang Research Project of China National Nuclear Corporation(CNNC-LCKY-202279)。
文摘The microstructures and corrosion behavior of 1.0wt%Gd-containing neutron-absorbing duplex stainless steel annealed at different temperatures were studied.Results reveal that the content of Gd-containing secondary phase increases with increasing the annealing temperatures to 1080℃,and then decreases.In the sample annealed at 1080℃,M-Gd(M=Fe,Cr,Ni)intermetallic with M_(3)Gd as the core phase and M_(12)Gd as the shell is the primary secondary phase.In the sample annealed at 1140℃,M_(3)Gd phase is dominant.The corrosion behavior of the two annealed steel samples were analyzed in NaCl,HCl and H_(3)BO_(3) solutions.It is found that the sample annealed at 1140℃ has lower corrosion rate.M_(3)Gd is more electrochemically active than M_(12)Gd when the sample is immersed in NaCl and HCl solutions,but more noble in H_(3)BO_(3) solution.
基金supported by the National Natural Science Foundation of China(Nos.52073290 and 51927803)the Science Fund for Distinguished Young Scholars of Liaoning Province(No.2023JH6/100500004)the Shenyang Science and Technology Plan Project(No.23-407-3-23).
文摘Mg_(3)Bi_(2)-based flms are promising near-room-temperature thermoelectric materials for the development of fexible thermoelectric devices.However,the high hole concentration caused by the abundance of intrinsic Mg vacancies easily leads to deterioration of electrical properties,especially for p-type Mg_(3)Bi_(2) flm.And the optimization of thermal conductivity of the Mg_(3)Bi_(2)-based flms is barely investigated.In this work,we demonstrate the improved thermoelectric performances of p-type Mg_(3)Bi_(2) through Ag doping by magnetron sputtering.This doping successfully reduces the hole concentration and broadens the band gap of Mg_(3)Bi_(2),thus resulting in a peak power factor of 442μW m−1 K−2 at 525 K.At the same time,Ag doping-induced fuctuations in mass and microscopic strain efectively enhanced the phonon scattering to reduce the lattice thermal conductivity.Consequently,a maximum thermoelectric fgure of merit of 0.22 is achieved at 525 K.Its near-roomtemperature thermoelectric performances demonstrate superior performance compared to many Mg_(3)Bi_(2)-based flms.To further evaluate its potential for thermoelectric power generation,we fabricated a thermoelectric device using Ag-doped Mg_(3)Bi_(2) flms,which achieved a power density of 864μW cm⁻2 at 35 K temperature diference.This study presents an efective strategy for the advancement of Mg_(3)Bi_(2)-based flms for application in micro-thermoelectric devices.
基金financially supported by the National Key Research and Development Program of China(2022YFE0110300)the National Natural Science Foundation of China(52261145696 and 52473187)+1 种基金the“111”Projectthe Collaborative Innovation Center of Suzhou Nano Science and Technology,Soochow University。
文摘Organic-inorganic hybrid solar cells consisting of organic conjugated materials and inorganic quantum dots(QDs)have been of great interest during the past two decades.However,it is still challenging to select desired organic functional materials for fabricating hybrid films to maximize their photovoltaic performance.Herein,we report the synthesis of three narrow bandgap non-fullerene conjugated polymers and further demonstrate the importance and impact of polymer crystallinity in tuning the organic-inorganic hybrid interface towards improved photovoltaic performance.In specific,we develop an organic-inorganic hybrid active layer using a newly synthesized polymer with relatively weaker crystallinity and FAPbI_(3)QDs,enabling complementary absorption and favorable interface/morphology for efficient charge separation and transport.The champion PCDOT-T/FAPbI_(3)QD hybrid device achieves a record-high efficiency of 13.11%based on the one-step coating organic/QD hybrid bulk heterojunction blend,which is significantly improved relative to the semi-crystalline polymer PYIT-based hybrid device(11.23%)and pristine QD(10.51%).We believe these findings would provide new insight into the organic/QD interface to construct desired hybrid films for high-performing optoelectronic applications.
基金supported by the National Natural Science Foundation of China(NSFC)under Grant Nos.52001313,52130002,52273322,and 52321001IMR Innovation Fund under Grant No.2023-PY05+3 种基金the Natural Science Foundation of Liaoning Province under Grant No.2022-MS-001the China Postdoctoral Science Foundation under Grant No.GZC20232740the Zhongke Technology Achievement Transfer and Transformation Center of Henan Province under Grant No.2024109the Joint Research Project between Chinese Academy of Sciences(CAS)under Grant No.174321KYSB20210002.
文摘Simultaneously improving the strength and electrical conductivity of conducting metallic materials is of great significance,but it still remains a key challenge as the two properties are often mutually exclusive.In this study,we demonstrate a“<111>oriented fibrous grains with ultra-high aspect ratio”strategy for breaking such a conflict in Cu wire,which relies on the distinctive spatial distribution of grain boundaries and the highly consistent hard orientation to play their respective roles in suffering loading and conducting,thereby enabling a separate optimization of both strength and electrical conductivity.Therefore,a processing route was designed,involving directional solidification followed by large drawing deformation,to successfully construct fibrous grains with an ultra-high aspect ratio in 596.7 and ultra-high<111>texture proportion over 97%,which achieves Cu wire with a remarkable combination of yield strength in 482.3 MPa and electrical conductivity in 101.63%IACS.Finally,the mechanisms for high strength and high electrical conductivity were quantitatively discussed.
基金support from the National Natural Science Foundation of China(Grant Nos.52321001 and 52071322).
文摘In the present study,a simple but effective two-step annealing processing strategy via manipulating the austenite reversion path is proposed to obtain a large fraction of retained austenite in low-Mn medium-Mn steels.Initially,the Fe-3Mn-0.2C-1.5Si(wt%)steel is intercritically annealed to form Mn-enriched lamellar martensite precursors.Subsequently,the austenite reversion transformation is manipulated to occur within the martensite lamellae during the second annealing process,resulting in an ultra-fine duplex microstructure of laminated austenite and ferrite.This process can not only allow a large fraction of austenite to be retained in low-Mn medium-Mn steels,but also increase the elongation by up to 41%without sacrificing the strength level compared to the conventional annealing.
基金supported by the National Natural Science Foun-dation of China(Nos.U1908219,52171163)the Key Research Program of the Chinese Academy of Sciences(No.ZDRW-CN-2021-2-2)+1 种基金the Applied Basic Research Program of Liaoning Province(grant no.2022JH2/101300005)the Central Guidance for Local Science and Technology Development Funds of Liaoning Province(grant no.2023JH6/100100016).
文摘Precipitation-strengthened HEAs exhibit outstanding integration of strength and toughness at ambient temperature.Nevertheless,precipitates generally reduce the localized corrosion resistance in aggressive solution environments.To solve this problem,a strategy of introducing nano-sized L12 precipitates in CoCrFeNiAlTi HEAs has been proposed in this work.Results demonstrate the pitting corrosion potential can be elevated from 258 mVSCE to 603 mVSCE by increasing the precipitate content to 38 wt.%.Such an improvement in localized corrosion resistance can be attributed to two aspects.Firstly,L12 precipitates tend to be dissolved during the corrosion process,which promotes the heterogeneous nucleation of protective Cr2 O3 due to the rapid deposition of oxides/hydroxides of Al/Ti,and improves the passive film stability due to the Crrich FCC matrix.Secondly,the dissolution kinetic inside the pits can be suppressed on account of the enrichment of Cr element in the FCC matrix,thus inhibiting the pitting growth.In summary,the current work not only reveals the mechanisms of the nano-sized L12 precipitates upon the corrosion behavior,but also provides a strategy for designing corrosion-resistant HEA.
基金supported by the Program of the National Natural Science Foundation of China(Grant No.52371055)the Young Elite Scientist Sponsorship Program Cast(Grant No.YESS20200139)+1 种基金the Basic Scientific Research Project of Liaoning Provincial Department of Education(Grant No.JYTMS20230618)Special thanks are due to the instrumental analysis from the Analytical and Testing Centre,Northeastern University.
文摘A principle was proposed for designing a method to seal anodized aluminum used in semiconductor processing apparatuses.Thermodynamic calculations and Fick’s second law were used to reveal trends in the metal ion deposition,deposition product stability,vapor pressures of halides for selected metal ions,the holding temperature,and time.Interactions between ion concentrations and the sealing temperature were also revealed.According to the design principles,anodized aluminum dipped in 1 mM Cr^(3+)ion solution and steam-sealed for 18 h exhibited the highest corrosion resistance when exposed to 5 wt.%HCl solution and HCl gas,verifying the designed results.
基金supported by the National Natural Science Foundation of China(grant Nos.52073290 and 51927803)the Liaoning Province Science and Technology Plan Project(No.2022-MS-011)the Shenyang science and technology plan project(23-407-3-23).
文摘Intermetallic Pt-based nanoparticles have displayed excellent activity for the oxygen reduction reaction(ORR)in fuel cells.However,it remains a great challenge to synthesize highly atomically ordered Pt-based nanoparticle catalysts because the formation of an atomically ordered structure usually requires high-temperature annealing accompanied by grain sintering.Here we report the direct epitaxial growth of well-aligned,highly atomically ordered Pt3 Fe and PtFe nanoparticles(<5 nm)on single-walled carbon nanotube(SWCNT)bundles films.The long-range periodically symmetric van der Waals(vdW)interac-tions between SWCNT bundles and Pt-Fe nanoparticles play an important role in promoting not only the alignment ordering of inter-nanoparticles but also the atomic ordering of intra-nanoparticles.The ordered Pt_(3)Fe/SWCNT catalyst showed enhanced ORR catalytic performance of 2.3-fold higher mass activity and 3.1-fold higher specific activity than commercial Pt/C.Moreover,the formation of an interlocked inter-face and strong vdW interaction endow the Pt-Fe/SWCNT catalysts with extreme long-term stability in potential cycling and excellent anti-thermal sintering ability.
