High-entropy alloy(HEA)nanoparticles(NPs)have attracted great attention in electrocatalysis due to their tailorable complex compositions and unique properties.Herein,we introduce Fe,Co,Ni,Cr and Mn into the metal-poly...High-entropy alloy(HEA)nanoparticles(NPs)have attracted great attention in electrocatalysis due to their tailorable complex compositions and unique properties.Herein,we introduce Fe,Co,Ni,Cr and Mn into the metal-polyphenol coordination system to prepare HEA NPs enclosed in N-doped carbon(FeCoNiCrMn)with great potential for catalyzing oxygen reduction reaction(ORR)and oxygen evolution reaction(OER).The unique high-entropy structural characteristics in FeCoNiCrMn facilitate effective interplay between metal species,leading to improved ORR(E_(1/2)=0.89 V)and OER(η=330 mV,j=10 mA·cm^(−2))activity.Additionally,FeCoNiCrMn exhibits excellent open-circuit voltage(1.523 V),power density(110 mW·cm^(−2))and long-term durability,outperforming Pt/C+IrO_(2) electrodes as a cathode catalyst in Zn-air batteries(ZABs).Such polyphenol-assisted alloying method broadens and simplifies the development of HEA electrocatalysts for high-performance ZABs.展开更多
Although traditional soft magnetic materials have been investigated to improve triboelectric nanogenerator(TENG)performance,their electrical output performance remains insufficient.Magnetic high-entropy alloys(HEAs),a...Although traditional soft magnetic materials have been investigated to improve triboelectric nanogenerator(TENG)performance,their electrical output performance remains insufficient.Magnetic high-entropy alloys(HEAs),a new type of magnetic functional material,possess excellent mechanical and magnetic properties.However,the electrical characteristics of TENGs based on magnetic HEAs remain unexplored.Therefore,a TENG based on polyvinylidene fluoride/HEA-polyamide 66(PHP-TENG)is proposed in this study.The coupling of displacement current from the polarization field and magnetization current generated by time-varying electric-field magnetization of magnetic HEAs can improve the electrical characteristics of TENGs.The maximum voltage,current,and power density of the PHP-TENG are 156.34 V,1.56μA,and 188.40 mW·m^(−2),respectively.PHP-TENG maintains a stable current output even after 20,000 cycles.Furthermore,it can power a 47μF commercial capacitor to 2.5 V in 70 s and propel a hygrometer to function normally.In addition,PHP-TENG exhibits satisfactory sensitivity to humidity.These results indicate that TENGs based on magnetic HEAs exhibit potential for high-efficiency energy-collecting devices.展开更多
The remarkable mechanical properties exhibited by laminated structures have generated significant in-terest in the realm of additively manufactured laminated high-entropy alloys(HEAs).Despite this bur-geoning interest...The remarkable mechanical properties exhibited by laminated structures have generated significant in-terest in the realm of additively manufactured laminated high-entropy alloys(HEAs).Despite this bur-geoning interest,the nexus between process,structure,and properties within laminated HEAs remains largely uncharted.There is a vast space for investigating the effect of the typical heterogeneous interface on the macroscopic mechanical properties.This study focuses on the influence of the characteristic het-erogeneous interface on macroscopic mechanical properties of laminated HEAs,particularly anisotropy.Using the 3D-printed Fe_(50)Mn_(30)Co_(10)Cr_(10)-CoCrNi HEA as a model,we investigate the impact of interface geometry on mechanical characteristics.Tensile tests show that the reduced interface spacing increases yield strength.This laminated HEA displays significant anisotropy in strength and ductility,depending on the loading direction relative to the interface.Electron microscopic observations suggest that finer layer spacing enhances interface and dislocation strengthening,increasing yield strength.Anisotropic behaviors are confirmed to be mediated by interface orientation,explained in terms of deformation compatibility and crack development at the interface.This research offers fundamental insights into the relationship between heterogeneous interfaces and the mechanical properties in laminated HEAs.The knowledge is vital for designing,fabricating,and optimizing laminated HEAs through additive manufacturing,advancing their engineering applications.展开更多
Exploiting the highly efficient electrocatalysts with ultra-low Pt content and extraordinary activity and durability for oxygen reduction reaction(ORR)is significantly crucial for breaking the bottle-neck of H_(2)/O_(...Exploiting the highly efficient electrocatalysts with ultra-low Pt content and extraordinary activity and durability for oxygen reduction reaction(ORR)is significantly crucial for breaking the bottle-neck of H_(2)/O_(2) fuel cell application.Herein,an ultra-fine high-entropy alloys(HEAs)sub-nanoparticles confined in graphene layer is successfully synthesized through a facile and universal solvent-free ball milling technique.The obtained PtFeCoNiMo sub-nanometer HEAs shows a uniform size of~1.3 nm(PtFeCoNiMo@C),representing the smallest HEAs reported to date.The PtFeCoNiMo@C exhibits exceptional ORR activity in pH-universal electrolytes,demonstrating 32 times(acidic),41 times(neutral),and 43 times(alkaline)mass-activities enhancement than commercial Pt/C(20%).The confined graphene layers enable the PtFeCoNiMo sub-nanoparticles high resistance to surface atomic reconfiguration,thus contributing to the outstanding durability with negligible E_(1/2) degradation after 100,000 cycles.The in-situ spectroscopy further reveals that the superior performance of PtFeCoNiMo@C is attributed to the optimized hydrogen bond structure and solvation environment at reaction interface,which accelerates the reaction kinetics.After assembling into proton exchange membrane fuel cells(PEMFCs),it achieves a peak power density of~1.4 W·cm^(-2) and minimal voltage loss(26 mV)after accelerated stability tests.This work provides a facile and effective methodology to large-scale(in 500 g batches)synthesize the sub-nanometer HEAs with superior activity,durability,and low cost,which can serve as promising alternative ORR electrocatalysts for PEMFCs.展开更多
The lightweight refractory high-entropy alloys(LRHEAs)are considered as next-generation high-performance weaponry matrix material.In this work,we employ the laser surface melting(LSM)method to ulteriorly optimize surf...The lightweight refractory high-entropy alloys(LRHEAs)are considered as next-generation high-performance weaponry matrix material.In this work,we employ the laser surface melting(LSM)method to ulteriorly optimize surface mechanical properties of Al_(0.5)NbTi_(3)VZr_(0.5) matrix HEA,where the phase structures,mechanical properties and deformation mechanism of as-cast and LSM-treated HEAs have been investigated.The LSM process eliminates tanglesome intermetallic Zr_(5)Al_(3) structures and effectively improves the mechanical properties of as-cast HEA.The sample after 2000 W LSM treatment exhibits the superior comprehensive mechanical properties,its tensile elongation,microhardness of remelt zone and volume wear loss are 31.6%,HV 809.6 and 296.4×10^(−3) mm^(3),representing the advancement of 85.9%,180.1%and 64.6%compared to that of as-cast HEA sample,respectively.Additionally,the deformation behavior of the as-cast sample involves solid phase transformation,stacking faults and deformation twinnings.The deformation mechanism of as-cast Al_(0.5)NbTi_(3)VZr_(0.5) HEA is transformation-induced plasticity(TRIP)and twinning-induced plasticity(TWIP),the classical Burgers mechanism of BCC→HCP solid phase transformation is revealed,which obeys[111]_(BCC)∥[1120]_(HCP).As for the 2000 W treated sample,the deformation mechanism is mainly TWIP as the stacking fault energy enhancement evidenced by the presence of cross-slip dislocations after LSM process.展开更多
The tensile behavior of(Fe_(50)Mn_(30)Co_(10)Cr_(10))_(100-x)Si_(x)(x=0(Si0),2(Si2))metastable HEAs prepared by selective laser melting was studied at cryogenic temperatures.The results demonstrate that the addition o...The tensile behavior of(Fe_(50)Mn_(30)Co_(10)Cr_(10))_(100-x)Si_(x)(x=0(Si0),2(Si2))metastable HEAs prepared by selective laser melting was studied at cryogenic temperatures.The results demonstrate that the addition of Si leads to lattice distortion and a decrease in stacking fault energy,especially at 77 K,which significantly promotes transformation-induced plasticity(TRIP)in Si2 HEAs.The yield strength,tensile strength,and ductility of Si2 HEAs are 505.2 MPa,1364.1 MPa,and 19%,which are 43%,53% and 58% higher than those of Si0 alloy,respectively.TRIP is the main deformation mode,in addition to dislocation slip,and plays a key role in strengthening.The reinforced and continuously sustained TRIP maintains a dynamic strain distribution during deformation.Ultrahigh strain hardening greatly enhances the strength and ductility.展开更多
基金supported by the Fundamental Research Funds for the Central Universities(No.22120230104).
文摘High-entropy alloy(HEA)nanoparticles(NPs)have attracted great attention in electrocatalysis due to their tailorable complex compositions and unique properties.Herein,we introduce Fe,Co,Ni,Cr and Mn into the metal-polyphenol coordination system to prepare HEA NPs enclosed in N-doped carbon(FeCoNiCrMn)with great potential for catalyzing oxygen reduction reaction(ORR)and oxygen evolution reaction(OER).The unique high-entropy structural characteristics in FeCoNiCrMn facilitate effective interplay between metal species,leading to improved ORR(E_(1/2)=0.89 V)and OER(η=330 mV,j=10 mA·cm^(−2))activity.Additionally,FeCoNiCrMn exhibits excellent open-circuit voltage(1.523 V),power density(110 mW·cm^(−2))and long-term durability,outperforming Pt/C+IrO_(2) electrodes as a cathode catalyst in Zn-air batteries(ZABs).Such polyphenol-assisted alloying method broadens and simplifies the development of HEA electrocatalysts for high-performance ZABs.
基金supported by the National Natural Science Foundation of China(No.52273077)the State Key Laboratory of Bio-Fibers&Eco-Textiles,Qingdao University(Nos.ZDKT202108 and G2RC202022).
文摘Although traditional soft magnetic materials have been investigated to improve triboelectric nanogenerator(TENG)performance,their electrical output performance remains insufficient.Magnetic high-entropy alloys(HEAs),a new type of magnetic functional material,possess excellent mechanical and magnetic properties.However,the electrical characteristics of TENGs based on magnetic HEAs remain unexplored.Therefore,a TENG based on polyvinylidene fluoride/HEA-polyamide 66(PHP-TENG)is proposed in this study.The coupling of displacement current from the polarization field and magnetization current generated by time-varying electric-field magnetization of magnetic HEAs can improve the electrical characteristics of TENGs.The maximum voltage,current,and power density of the PHP-TENG are 156.34 V,1.56μA,and 188.40 mW·m^(−2),respectively.PHP-TENG maintains a stable current output even after 20,000 cycles.Furthermore,it can power a 47μF commercial capacitor to 2.5 V in 70 s and propel a hygrometer to function normally.In addition,PHP-TENG exhibits satisfactory sensitivity to humidity.These results indicate that TENGs based on magnetic HEAs exhibit potential for high-efficiency energy-collecting devices.
基金supported by the National Natural Science Foundation of China(No.12272392 and 11790292)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB22040303)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.2022020).
文摘The remarkable mechanical properties exhibited by laminated structures have generated significant in-terest in the realm of additively manufactured laminated high-entropy alloys(HEAs).Despite this bur-geoning interest,the nexus between process,structure,and properties within laminated HEAs remains largely uncharted.There is a vast space for investigating the effect of the typical heterogeneous interface on the macroscopic mechanical properties.This study focuses on the influence of the characteristic het-erogeneous interface on macroscopic mechanical properties of laminated HEAs,particularly anisotropy.Using the 3D-printed Fe_(50)Mn_(30)Co_(10)Cr_(10)-CoCrNi HEA as a model,we investigate the impact of interface geometry on mechanical characteristics.Tensile tests show that the reduced interface spacing increases yield strength.This laminated HEA displays significant anisotropy in strength and ductility,depending on the loading direction relative to the interface.Electron microscopic observations suggest that finer layer spacing enhances interface and dislocation strengthening,increasing yield strength.Anisotropic behaviors are confirmed to be mediated by interface orientation,explained in terms of deformation compatibility and crack development at the interface.This research offers fundamental insights into the relationship between heterogeneous interfaces and the mechanical properties in laminated HEAs.The knowledge is vital for designing,fabricating,and optimizing laminated HEAs through additive manufacturing,advancing their engineering applications.
基金supported by the National Natural Science Foundation of China(Nos.22475031 and 22409025)the National Youth Top-notch Talent Support Program of China.
文摘Exploiting the highly efficient electrocatalysts with ultra-low Pt content and extraordinary activity and durability for oxygen reduction reaction(ORR)is significantly crucial for breaking the bottle-neck of H_(2)/O_(2) fuel cell application.Herein,an ultra-fine high-entropy alloys(HEAs)sub-nanoparticles confined in graphene layer is successfully synthesized through a facile and universal solvent-free ball milling technique.The obtained PtFeCoNiMo sub-nanometer HEAs shows a uniform size of~1.3 nm(PtFeCoNiMo@C),representing the smallest HEAs reported to date.The PtFeCoNiMo@C exhibits exceptional ORR activity in pH-universal electrolytes,demonstrating 32 times(acidic),41 times(neutral),and 43 times(alkaline)mass-activities enhancement than commercial Pt/C(20%).The confined graphene layers enable the PtFeCoNiMo sub-nanoparticles high resistance to surface atomic reconfiguration,thus contributing to the outstanding durability with negligible E_(1/2) degradation after 100,000 cycles.The in-situ spectroscopy further reveals that the superior performance of PtFeCoNiMo@C is attributed to the optimized hydrogen bond structure and solvation environment at reaction interface,which accelerates the reaction kinetics.After assembling into proton exchange membrane fuel cells(PEMFCs),it achieves a peak power density of~1.4 W·cm^(-2) and minimal voltage loss(26 mV)after accelerated stability tests.This work provides a facile and effective methodology to large-scale(in 500 g batches)synthesize the sub-nanometer HEAs with superior activity,durability,and low cost,which can serve as promising alternative ORR electrocatalysts for PEMFCs.
基金supported by the Science and Technology Innovation Fund Project of GRIMAT Engineering Institute Co.,Ltd.,China,the National Key R&D Program of China(No.2023YFB3710403).
文摘The lightweight refractory high-entropy alloys(LRHEAs)are considered as next-generation high-performance weaponry matrix material.In this work,we employ the laser surface melting(LSM)method to ulteriorly optimize surface mechanical properties of Al_(0.5)NbTi_(3)VZr_(0.5) matrix HEA,where the phase structures,mechanical properties and deformation mechanism of as-cast and LSM-treated HEAs have been investigated.The LSM process eliminates tanglesome intermetallic Zr_(5)Al_(3) structures and effectively improves the mechanical properties of as-cast HEA.The sample after 2000 W LSM treatment exhibits the superior comprehensive mechanical properties,its tensile elongation,microhardness of remelt zone and volume wear loss are 31.6%,HV 809.6 and 296.4×10^(−3) mm^(3),representing the advancement of 85.9%,180.1%and 64.6%compared to that of as-cast HEA sample,respectively.Additionally,the deformation behavior of the as-cast sample involves solid phase transformation,stacking faults and deformation twinnings.The deformation mechanism of as-cast Al_(0.5)NbTi_(3)VZr_(0.5) HEA is transformation-induced plasticity(TRIP)and twinning-induced plasticity(TWIP),the classical Burgers mechanism of BCC→HCP solid phase transformation is revealed,which obeys[111]_(BCC)∥[1120]_(HCP).As for the 2000 W treated sample,the deformation mechanism is mainly TWIP as the stacking fault energy enhancement evidenced by the presence of cross-slip dislocations after LSM process.
基金supported by Program for Innovative Research Team in Science and Technology in Fujian Province University,Chinathe Natural Science Foundation of Fujian Province,China(Nos.2023J011013,2020J01898)。
文摘The tensile behavior of(Fe_(50)Mn_(30)Co_(10)Cr_(10))_(100-x)Si_(x)(x=0(Si0),2(Si2))metastable HEAs prepared by selective laser melting was studied at cryogenic temperatures.The results demonstrate that the addition of Si leads to lattice distortion and a decrease in stacking fault energy,especially at 77 K,which significantly promotes transformation-induced plasticity(TRIP)in Si2 HEAs.The yield strength,tensile strength,and ductility of Si2 HEAs are 505.2 MPa,1364.1 MPa,and 19%,which are 43%,53% and 58% higher than those of Si0 alloy,respectively.TRIP is the main deformation mode,in addition to dislocation slip,and plays a key role in strengthening.The reinforced and continuously sustained TRIP maintains a dynamic strain distribution during deformation.Ultrahigh strain hardening greatly enhances the strength and ductility.
