Metal-ceramic composites combine the excellent properties of metals and ceramics,which have high strength,stability,and corrosion re-sistance.Al_(2)O_(3)/FeCo composites have been proven to be useful in ap-plications ...Metal-ceramic composites combine the excellent properties of metals and ceramics,which have high strength,stability,and corrosion re-sistance.Al_(2)O_(3)/FeCo composites have been proven to be useful in ap-plications such as catalysts,mi-crowave absorption materials,and enhanced permeability dielectric.The understanding of the mechani-cal properties and dynamics at the atomic scale of the Al_(2)O_(3)/FeCo in-terface can promote the design and exploitment of metal-ceramic composites.In this work,we have obtained Young’s modulus and diffusion coefficient of the Al_(2)O_(3)/FeCo interface using molecular dynamics simulation,elucidated the structural characteristics of the Al_(2)O_(3)/FeCo interface at the atomic scale,and investigated the impact of atomic magnetism and the exter-nal magnetic field on the interface.Simulated results show that Young’s modulus of the Al_(2)O_(3)/FeCo interface is significantly improved compared with pure Al_(2)O_(3)and FeCo alloy at room and high temperatures.When the atomic magnetism and the external magnetic field are applied,Young’s modulus of the Al_(2)O_(3)/FeCo interface further increases to 612 GPa at 300 K and 602 GPa at 500 K.Moreover,the average density,diffusion coefficient,and radial distri-bution function are found to be modified substantially.This study will shed light on the atom-istic investigations of the metal-ceramic composites.展开更多
The difficulty in fabricating a multifaceted composite heterojunction system based on Cd_(x) Zn_(1-x) S limits the enhancement of photocatalytic performance.In the present scrutiny,novel ZnO/Cd_(x) Zn_(1-x) S/CdS com-...The difficulty in fabricating a multifaceted composite heterojunction system based on Cd_(x) Zn_(1-x) S limits the enhancement of photocatalytic performance.In the present scrutiny,novel ZnO/Cd_(x) Zn_(1-x) S/CdS com-posite heterojunctions are successfully prepared by the alkaline dissolution etching method.The internal electric field at the interface of I-type and Z-scheme heterojunction improved the effective charge sepa-ration.The ZC 8 sample exhibits excellent photocatalytic performance and the H2 production efficiency is 15.67 mmol g^(−1) h^(−1) with good stability up to 82.9%in 24-hour cycles.The performance of CH_(4) and CO capacity in the CO_(2) RR process is 3.47μmol g^(−1) h^(−1) and 23.5μmol g^(−1) h^(−1),respectively.The photogener-ated accelerated charge transport is then examined in detail by in situ X-ray photoelectron spectroscopy(ISXPS)and density functional theory(DFT)calculations.This work presents a new idea for the synthe-sis of Cd_(x) Zn_(1-x) S solid-solution-based materials and provides a solid reference for the detailed mechanism regarding the electric field at the heterojunction interface.展开更多
Focusing on the low open circuit voltage(V_(OC))and fill factor(FF)in flexible Cu_(2)ZnSn(S,Se)_(4)(CZTSSe)solar cells,indium(In)ions are introduced into the CZTSSe absorbers near Mo foils to modify the back interface...Focusing on the low open circuit voltage(V_(OC))and fill factor(FF)in flexible Cu_(2)ZnSn(S,Se)_(4)(CZTSSe)solar cells,indium(In)ions are introduced into the CZTSSe absorbers near Mo foils to modify the back interface and passivate deep level defects in CZTSSe bulk concurrently for improving the performance of flexible device.The results show that In doping effectively inhibits the formation of secondary phase(Cu(S,Se)_(2))and VSndefects.Further studies demonstrate that the barrier height at the back interface is decreased and the deep level defects(Cu_(Sn)defects)in CZTSSe bulk are passivated.Moreover,the carrier concentration is increased and the V_(OC) deficit(V_(OC,def))is decreased significantly due to In doping.Finally,the flexible CZTSSe solar cell with 10.01%power conversion efficiency(PCE)has been obtained.The synergistic strategy of interface modification and bulk defects passivation through In incorporation provides a new thought for the fabrication of efficient flexible kesterite-based solar cells.展开更多
Rechargeable magnesium-ion(Mg-ion)batteries have attracted wide attention for energy storage.However,magnesium anode is still limited by the irreversible Mg plating/stripping procedure.Herein,a well-designed binary Bi...Rechargeable magnesium-ion(Mg-ion)batteries have attracted wide attention for energy storage.However,magnesium anode is still limited by the irreversible Mg plating/stripping procedure.Herein,a well-designed binary Bi_(2)O_(3)-Bi_(2)S_(3)(BO-BS)heterostructure is fulfilled by virtue of the cooperative interface and energy band engineering targeted fast Mg-ion storage.The built-in electronic field resulting from the asymmetrical electron distribution at the interface of electron-rich S center at Bi_(2)S_(3) side and electron-poor O center at Bi_(2)O_(3) side effectively accelerates the electrochemical reaction kinetics in the Mg-ion battery system.Moreover,the as-designed heterogenous interface also benefits to maintaining the electrode integrity.With these advantages,the BO-BS electrode displays a remarkable capacity of 150.36 mAh g^(−1) at 0.67 A g^(-1) and a superior cycling stability.This investigation would offer novel insights into the rational design of functional heterogenous electrode materials targeted the fast reaction kinetics for energy storage systems.展开更多
In the welding process of SiCp/Al composites,Al reacts with SiC particles in the molten pool to form Al_(4)C_(3),a brittle phase,damaging the reinforcement and causing a sharp decline in the mechanical properties of w...In the welding process of SiCp/Al composites,Al reacts with SiC particles in the molten pool to form Al_(4)C_(3),a brittle phase,damaging the reinforcement and causing a sharp decline in the mechanical properties of weld joints.To mitigate this,a method of welding SiCp/Al composites by pulsed laser welding with powder-filling is proposed,inhibiting the interface reaction between Al and SiC particles in the molten pool.This study investigates the effect of pulse frequency on the temperature field of the molten pool,and combines thermal-fluid numerical simulation to analyze the peak temperature at different pulse frequencies,optimizing the Si content to ultimately inhibit the interface reaction in the molten pool.Results indicate that an appropriate pulse frequency achieves good welding formation and effectively regulates the peak temperature of the molten pool.Only a small amount of brittle phase is present in the weld joint,creating favorable conditions for the addition of alloying elements.The interface reaction is slowed down by adjusting the pulse frequency,though it is not completely inhibited.When the addition of Si content reaches 8%,the occurrence of the interface reaction is effectively inhibited.In weld joints with the addition of 8wt%Si powder,no Al_(4)C_(3)brittle phase is present,and the tensile strength of the weld joint is 266 MPa,up to 70%of the base material.展开更多
基金supported by the National Natural Science Foundation of China(Nos.22173057,52130204,12074241,11929401,12311530675)Science and Technology Commission of Shanghai Municipality(Nos.21JC1402700,22XD1400900,20501130600,21JC1402600)High-Performance Computing Center,Shanghai Technical Service Center of Science and Engineering Computing,Shanghai University。
文摘Metal-ceramic composites combine the excellent properties of metals and ceramics,which have high strength,stability,and corrosion re-sistance.Al_(2)O_(3)/FeCo composites have been proven to be useful in ap-plications such as catalysts,mi-crowave absorption materials,and enhanced permeability dielectric.The understanding of the mechani-cal properties and dynamics at the atomic scale of the Al_(2)O_(3)/FeCo in-terface can promote the design and exploitment of metal-ceramic composites.In this work,we have obtained Young’s modulus and diffusion coefficient of the Al_(2)O_(3)/FeCo interface using molecular dynamics simulation,elucidated the structural characteristics of the Al_(2)O_(3)/FeCo interface at the atomic scale,and investigated the impact of atomic magnetism and the exter-nal magnetic field on the interface.Simulated results show that Young’s modulus of the Al_(2)O_(3)/FeCo interface is significantly improved compared with pure Al_(2)O_(3)and FeCo alloy at room and high temperatures.When the atomic magnetism and the external magnetic field are applied,Young’s modulus of the Al_(2)O_(3)/FeCo interface further increases to 612 GPa at 300 K and 602 GPa at 500 K.Moreover,the average density,diffusion coefficient,and radial distri-bution function are found to be modified substantially.This study will shed light on the atom-istic investigations of the metal-ceramic composites.
基金financially supported by the National Key Re-search and Development Program of China[No.2022YFF1202500,2022YFF1202502]the National Natural Science Foundation of China[62071459]+1 种基金the Subject arrangement Foundation of Shen-zhen[No.JCYJ20180507182057026]the International Science and Technology Cooperation Project of Bingtuan[No.2022BC008]。
文摘The difficulty in fabricating a multifaceted composite heterojunction system based on Cd_(x) Zn_(1-x) S limits the enhancement of photocatalytic performance.In the present scrutiny,novel ZnO/Cd_(x) Zn_(1-x) S/CdS com-posite heterojunctions are successfully prepared by the alkaline dissolution etching method.The internal electric field at the interface of I-type and Z-scheme heterojunction improved the effective charge sepa-ration.The ZC 8 sample exhibits excellent photocatalytic performance and the H2 production efficiency is 15.67 mmol g^(−1) h^(−1) with good stability up to 82.9%in 24-hour cycles.The performance of CH_(4) and CO capacity in the CO_(2) RR process is 3.47μmol g^(−1) h^(−1) and 23.5μmol g^(−1) h^(−1),respectively.The photogener-ated accelerated charge transport is then examined in detail by in situ X-ray photoelectron spectroscopy(ISXPS)and density functional theory(DFT)calculations.This work presents a new idea for the synthe-sis of Cd_(x) Zn_(1-x) S solid-solution-based materials and provides a solid reference for the detailed mechanism regarding the electric field at the heterojunction interface.
基金supported by the National Natural Science Foundation of China(62074037)the Science and Technology Department of Fujian Province(2020I0006)the Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China(2021ZZ124)。
文摘Focusing on the low open circuit voltage(V_(OC))and fill factor(FF)in flexible Cu_(2)ZnSn(S,Se)_(4)(CZTSSe)solar cells,indium(In)ions are introduced into the CZTSSe absorbers near Mo foils to modify the back interface and passivate deep level defects in CZTSSe bulk concurrently for improving the performance of flexible device.The results show that In doping effectively inhibits the formation of secondary phase(Cu(S,Se)_(2))and VSndefects.Further studies demonstrate that the barrier height at the back interface is decreased and the deep level defects(Cu_(Sn)defects)in CZTSSe bulk are passivated.Moreover,the carrier concentration is increased and the V_(OC) deficit(V_(OC,def))is decreased significantly due to In doping.Finally,the flexible CZTSSe solar cell with 10.01%power conversion efficiency(PCE)has been obtained.The synergistic strategy of interface modification and bulk defects passivation through In incorporation provides a new thought for the fabrication of efficient flexible kesterite-based solar cells.
基金supported by the National Natural Science Foundation of China(52172239)Project of State Key Laboratory of Environment-Friendly Energy Materials(SWUST,Grant Nos.22fksy23 and 18ZD320304)+3 种基金the Frontier Project of Chengdu Tianfu New Area Institute(SWUST,Grand No.2022ZY017)Chongqing Talents:Exceptional Young Talents Project(Grant No.CQYC201905041)Natural Science Foundation of Chongqing China(Grant No.cstc2021jcyj-jqX0031)Interdiscipline Team Project under auspices of“Light of West”Program in Chinese Academy of Sciences(Grant No.xbzg-zdsys-202106).
文摘Rechargeable magnesium-ion(Mg-ion)batteries have attracted wide attention for energy storage.However,magnesium anode is still limited by the irreversible Mg plating/stripping procedure.Herein,a well-designed binary Bi_(2)O_(3)-Bi_(2)S_(3)(BO-BS)heterostructure is fulfilled by virtue of the cooperative interface and energy band engineering targeted fast Mg-ion storage.The built-in electronic field resulting from the asymmetrical electron distribution at the interface of electron-rich S center at Bi_(2)S_(3) side and electron-poor O center at Bi_(2)O_(3) side effectively accelerates the electrochemical reaction kinetics in the Mg-ion battery system.Moreover,the as-designed heterogenous interface also benefits to maintaining the electrode integrity.With these advantages,the BO-BS electrode displays a remarkable capacity of 150.36 mAh g^(−1) at 0.67 A g^(-1) and a superior cycling stability.This investigation would offer novel insights into the rational design of functional heterogenous electrode materials targeted the fast reaction kinetics for energy storage systems.
基金Supported by Equipment Pre-Research Foundation of China(Grant No.50923030512)。
文摘In the welding process of SiCp/Al composites,Al reacts with SiC particles in the molten pool to form Al_(4)C_(3),a brittle phase,damaging the reinforcement and causing a sharp decline in the mechanical properties of weld joints.To mitigate this,a method of welding SiCp/Al composites by pulsed laser welding with powder-filling is proposed,inhibiting the interface reaction between Al and SiC particles in the molten pool.This study investigates the effect of pulse frequency on the temperature field of the molten pool,and combines thermal-fluid numerical simulation to analyze the peak temperature at different pulse frequencies,optimizing the Si content to ultimately inhibit the interface reaction in the molten pool.Results indicate that an appropriate pulse frequency achieves good welding formation and effectively regulates the peak temperature of the molten pool.Only a small amount of brittle phase is present in the weld joint,creating favorable conditions for the addition of alloying elements.The interface reaction is slowed down by adjusting the pulse frequency,though it is not completely inhibited.When the addition of Si content reaches 8%,the occurrence of the interface reaction is effectively inhibited.In weld joints with the addition of 8wt%Si powder,no Al_(4)C_(3)brittle phase is present,and the tensile strength of the weld joint is 266 MPa,up to 70%of the base material.
