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Dual-phase medium-entropy diboride–carbide ceramics with metal element exchange during sintering

Journal of advanced Ceramics 2025年第1期14卷 91-100页

作者： Pai Peng Ji-Xuan Liu Xiao-Ting Xin Weichao Bao Yongcheng Liang Fangfang Xu Guo-Jun Zhang State Key Laboratory of Advanced Fiber Materials Institute of Functional MaterialsCollege of Materials Science and EngineeringCollege of PhysicsDonghua UniversityShanghai 201620China State Key Laboratory of High Performance Ceramics and Superfine Microstructure Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050China

Multiphase composition design is a strategy for optimizing the microstructures and properties of ceramic materials through mutual inhibition of grain growth, complementary property improvement, or even mutually reinforcing effects. More interesting phenomena can be expected if chemical interactions between the constituent phases exist. In this study, spark plasma sintering was used to prepare fully dense dual-phase (Zr,Hf,Ta)B_(2)–(Zr,Hf,Ta)C ceramics from self-synthesized equimolar medium-entropy diboride and carbide powders. The obtained ceramics were composed of two distinct solid solution phases, the Zr-rich diboride phase and the Ta-rich carbide phase, indicating that metal element exchange occurred between the starting equimolar medium-entropy diboride and carbide phases during sintering. Owing to the mutual grain-boundary pinning effect, fine-grained dual-phase ceramics were obtained. The chemical driving force originating from metal element exchange during the sintering process is considered to promote the densification process of the ceramics. The metal element exchange between the medium-entropy diboride and carbide phases significantly increased the Young’s modulus of the dual-phase ceramics. The dual-phase medium-entropy 50 vol% (Zr,Hf,Ta)B_(2)–50 vol% (Zr,Hf,Ta)C ceramics with the smallest grain size exhibited the highest hardness of 22.4±0.2 GPa. It is inferred that optimized comprehensive properties or performance of dual-phase high-entropy or medium-entropy ceramics of diborides and carbides can be achieved by adjusting both the volume content and the metal element composition of the corresponding starting powders of diborides and carbides.

关键词： medium-entropy diboride medium-entropy carbide dual-phase medium-entropy ceramics metal element exchange densification mechanical properties

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Enhanced room temperature CO2 photoreduction on gas-solid interfaces using nanocrystals integrated with ZIF-8 wrapping design

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材料科学技术（英文版） 2025年第6期209卷 55-63页

作者： Xiaoxiong Hou Zhuangzhuang Ma Zhilei Zhang Xiaotong Gao Hongqiang Wang Lichao Jia Key Laboratory of Applied Surface and Colloid Chemistry Shaanxi Key Laboratory for Advanced Energy DevicesShaanxi Engineering Lab for Advanced Energy TechnologySchool of Materials Science and EngineeringNational Ministry of EducationShaanxi Normal UniversityXi'an 710119China Beijing National Laboratory for Molecular Sciences Key Laboratory of Organic SolidsInstitute of ChemistryChinese Academy of SciencesBeijing 100190China University of the Chinese Academy of Sciences Beijing 100049China State Key Laboratory of Solidification Processing Center for Nano Energy MaterialsSchool of Materials Science and EngineeringNorthwestern Polytechnical University and Shaanxi Joint Laboratory of GrapheneXi'an 710072China

Composites derived from metal-organic frameworks(MOFs)show promise as catalysts for the photocat-alytic reduction of ***,their potential is hindered by constraints such as limited light absorp-tion and sluggish electron transfer and separation,impacting the overall efficiency of the photocatalytic *** this study,TiO2 nanocrystals,modified with Ptx+,underwent laser etching were encapsulated within the traditional MOF-ZIF-8 *** enhanced the adsorption capabilities for CO2 reactants and solar light,while also facilitating directed electron transfer and the separation of photogenerated *** finely-tuned catalyst demonstrates impressive CH4 selectivity at 9.5％,with yields of 250.24 μmol g-1 h-1 for CO and 25.43 μmol g-1 h-1 for CH4,utilizing water as a hole trap and H+*** study demonstrates the viability of achieving characteristics related to the separation of photogen-erated charges in TiO2 nanocrystals through laser etching and MOF composite *** offers novel perspectives for designing MOF-based catalysts with enhanced performance in artificial photosynthesis.

关键词： CO2 photoreduction Nanocrystals TiO2 ZIF-8 Wrapping structure

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Pushing the high-k scalability limit with a superparaelectric gate layer

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Journal of advanced Ceramics 2024年第4期13卷 539-547页

作者： Kun Wang Chao Liu Yuan Zhang Fuyu Lv Jun Ouyang Houbing Huang Rui-Long Yang Yu-Yao Zhao Hongbo Cheng Hanfei Zhu Xiaoming Shi Yun Tian Institute of Advanced Energy Materials and Chemistry Jinan Engineering Laboratory for Multi-scale Functional MaterialsSchool of Chemistry and Chemical EngineeringQilu University of Technology(Shandong Academy of Sciences)Jinan 250353China Key Laboratory for Liquid-Solid Structure Evolution and Processing of Materials(Ministry of Education) School of Materials Science and EngineeringShandong UniversityJinan 250061China China Tobacco Shandong Industrial Co. Ltd.Jinan 250104China Department of Materials Science and Engineering Southern University of Science and TechnologyShenzhen 518055China Key Laboratory of Key Film Materials&Application for Equipments(Hunan Province) School of Material Sciences and EngineeringXiangtan UniversityXiangtan 411105China Advanced Research Institute of Multidisciplinary Science and School of Materials Science and EngineeringBeijing Institute of TechnologyBeijing 100081China Key Laboratory of Magnetic Molecules and Magnetic Information Materials of Ministry of Education School of Chemistry and Materials ScienceShanxi Normal UniversityTaiyuan 030032China

To meet the expectation set by Moore’s law on transistors,the search for thickness-scalable high dielectric constant(k)gate layers has become an emergent research *** investigations have failed to solve the“polarizability–scalability–insulation robustness”*** this work,we show that this trilemma can be solved by using a gate layer of a high k ferroelectric oxide in its superparaelectric(SPE)*** the SPE,its polar order becomes local and is dispersed in an amorphous matrix with a crystalline size down to a few nanometers,leading to an excellent dimensional scalability and a good field-stability of the k *** an example,a stable high k value(37±3)is shown in ultrathin SPE films of(Ba_(0.95),Sr_(0.05))(Zr_(0.2),Ti_(0.8))O_(3)deposited on LaNiO_(3)-buffered Pt/Ti/SiO_(2)/(100)Si down to a 4 nm thickness,leading to a small equivalent oxide thickness of~0.46 *** aforementioned characteristic microstructure endows the SPE film a high breakdown strength(~10.5 MV·cm^(−1)for the 4 nm film),and hence ensures a low leakage current for the operation of the complementary metal oxide semiconductor(CMOS)***,a high electrical fatigue resistance is displayed by the SPE *** results reveal a great potential of superparaelectric materials as gate dielectrics in the next-generation microelectronics.

关键词： high-k transistors Moore's law superparaelectric insulation robustness

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Covalence bridge atomically precise metal nanocluster and metalorganic frameworks for enhanced photostability and photocatalysis

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Nano Research 2023年第1期16卷 1527-1532页

作者： Aimin Yao Yuanxin Du Meng Han Yan Wang Jiashen Hu Qingtao Zhu Hongting Sheng Manzhou Zhu Department of Materials Science and Engineering Centre for Atomic Engineering of Advanced MaterialsKey Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of EducationKey Laboratory of Functional Inorganic Material Chemistry of Anhui ProvinceAnhui UniversityHefei 230601China

Metal nanoclusters(NCs)with precise structure and ultrasmall size have attracted great interests in ***,the poor stability has limited its large-scale ***,we proposed the“covalence bridge”strategy to effectively connect atomically precise metal NCs and metal-organic *** from the covalent linkage,the synthesized UiO-66-NH2-Au25(LCys)18 showed outstanding stability after 16 h ***,the covalence bridge created a strong metal-support interaction between the two components and provided an effective charge transport channel and thereby enhanced photocatalytic ***-66-NH2-Au25(L-Cys)18 displayed an exceptional photocatalytic H2 production rate,which is 21 and 90 times higher than that of UiO-66-NH2/Au25(PET)18(made by physically combination)and bare UiO-66-NH2,*** and kinetic studies demonstrated that UiO-66-NH2-Au25(L-Cys)18 exhibited higher charge transfer efficiency,lower overpotential of water reduction and activation energy barrier compared with its counterparts.

关键词： atomically precise nanoclusters metal-organic frameworks covalent binding photostability photocatalytic hydrogen production

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In situ regulating intimately connected heterostructure by decomposition of solid solution oxides toward high-efficient water oxidation

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Rare Metals 2024年第4期43卷 1557-1569页

作者： Shao-Fei Zhang Xiao-Lu Yin Jin Wang Jian-Li Kang Tian-Tian Li Jin-Feng Sun Yong-Qiang Meng Jian-Jiang Wang Dian-Long Wang Kai-Qiang Qin Hebei Key Laboratory of Flexible Functional Materials/Hebei Key Laboratory of Material Near-Net Forming Technology School of Materials Science and EngineeringHebei University of Science and TechnologyShijiazhuang050018China Key Laboratory of Advanced Ceramics and Machining Technology/Ministry of Education School of Materials Science and EngineeringTianjin UniversityTianjin300072China Electrochemical Engine Center Department of Mechanical EngineeringPennsylvania State UniversityUniversity ParkPA16802USA

Heterogeneous interfaces produced by interdomain interactions on a nanoscale performs a crucial role in boosting the properties of an electrocatalyst toward oxygen evolution reaction(OER)***,a series of dual-phase electrodes with intimately connected heterointerfaces are prepared by in situ decomposing solid solution oxide of Ni_(x)Co_(y)Fe_(100-x-y)O,which grew on Ni foam massively via an ultrafast combustion ***,with high-reaction kinetics caused by the reduction treatment at 450℃,the less electronegative Fe and Co are more oxyphilic than Ni,which facilitated their co-exsolution and formation of CoFe_2O_4/NiO oxide with enriched oxygen *** from the nanoporous framework,heterojunction structure,and oxygen defects,the self-supporting electrodes present rapid charge/mass transmission and provide abundant active sites for *** optimized sample(R-SNCF4.5)shows low overpotentials of 226 and 324 mV at 10 and100 mA·cm^(-2),a small Tafel slope(46.7 mV·dec^(-1)),and excellent *** assembled R-SNCF4.5//Pt/C/NF electrolyzer demonstrates continuous electrolysis over 50 h at a current density of 10 mA·cm^(-2),under 1.51 *** functional theory(DFT)calculations verify that the strong electronic modulation plays a critical part in the CoFe_2O_4/NiO hybrid by lowering the energy barriers for the ratedetermining steps,and Fe sites are the most active OER sites.

关键词： Rapid combustion Decomposition of solid solution oxide Dual-phase heterostructure Oxygen evolution reaction Theoretical calculation

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Readily prepared and processed multifunctional MXene nanocomposite hydrogels for smart electronics

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SmartMat 2024年第2期5卷 103-114页

作者： Jiahui Huang Xianwu Huang Peiyi Wu State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Chemistry and Chemical EngineeringCenter for Advanced Low-Dimension MaterialsDonghua UniversityShanghaiChina State Key Laboratory of Molecular Engineering of Polymers Department of Macromolecular Science and Laboratory of Advanced MaterialsFudan UniversityShanghaiChina

Booming sophisticated robotics and prosthetics put forward high requirements on soft conductive materials that can bridge electronics and biology,those soft conductive materials should imitate the mechanical properties of biological tissues and build information transmission *** now,it remains a great challenge to handle the trade-off among ease of preparation,high conductivity,processability,mechanical adaptability,and external stimuli ***,a kind of readily prepared and processed multifunctional MXene nanocomposite hydrogel is reported,which is prepared via the fast gelation of cationic monomer initiated by delaminated MXene *** gelation time can be adjusted(several seconds to minutes)based on the MXene *** adjusting the MXene ratio,the resulting nanocomposites are ultrastretchable(>5000%),three-dimensional(3D)printable,and show outstanding mechanical and electrical *** expected,the integration of multifunctional systems onto various substrates(e.g.,gloves and masks)is further demonstrated via 3D printing and could achieve diverse sensory capabilities toward strain,pressure,and temperature,showing great prospects as smart flexible electronics.

关键词： 3D printable electronics MXene polymeric hydrogels stretchable and conductive

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Interactive effect of thermal aging and proton irradiation on microstructural evolution and hardening ofδ-ferrite in 308L stainless steel weld metal

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Journal of materials science & Technology 2024年第3期170卷 140-155页

作者： Xiaodong Gao Xiaodong Lin Tao Guo Lining Xu Yaolei Han Baolong Jiang Xingyuan Mei Qunjia Peng Lijie Qiao Beijing Advanced Innovation Center for Materials Genome Engineering Institute of Advanced Materials and TechnologyUniversity of Science and Technology BeijingBeijing 100083China Institute of Materials Shanghai UniversityShanghai 200072China School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China Suzhou Nuclear Power Research Institute Suzhou 215004China State Key Laboratory for Advanced Metals and Materials University of Science and Technology BeijingBeijing 100083China

In the harsh service environment of high temperature and intense neutron irradiation in water-cooled nuclear reactors,the austenitic stainless steel weld overlay cladding on the inner surface of the reactor pressure vessel suffers from thermal aging and irradiation damage simultaneously,which can induce microstructural evolution and hardening of the *** it is quite difficult to achieve this simul-taneous process out of the pile,two kinds of combined experiments,i.e.,post-irradiation thermal aging and post-aging irradiation were performed on 308 L stainless steel weld metals in this *** interactive effect of thermal aging and proton irradiation on microstructural evolution and hardening ofδ-ferrite in 308 L weld metal was investigated by combining atom probe tomography,transmission elec-tron microscopy and nanoindentation *** results revealed that thermal aging could eliminate the dislocation loops induced by irradiation and affect the phase transition process by accelerating spinodal decomposition and G-phase precipitation,thus enhancing hardening of irradiatedδ-*** the effect of irradiation on the microstructure and hardening of thermally agedδ-ferrite,however,intensive collision cascades can intensify G-phase precipitation and dislocation loop formation but decrease spinodal decomposition,leading to a limited effect on hardening of thermally agedδ-***,the interaction of thermal aging and irradiation can promote G-phase ***,the interaction can causeδ-ferrite hardening,which is mainly influenced by spinodal decomposition,followed by G-phase and dislocation loops,where spinodal decomposition and G-phase cause hardening by inducing strain fields.

关键词： Austenitic stainless steel weld metals Thermal aging Proton irradiation Interaction Microstructural evolution Hardening

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A modified maxwell-pulse thermoplastic constitutive model of in-situ Ta-particle reinforced Zr-based bulk metallic glass composites

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Progress in Natural science:materials International 2024年第4期34卷 753-766页

作者： Pan Gong Zhuang Wang Guoqing Yu Maojun Li Xin Zhuo Xuefeng Tang Mao Zhang Lei Deng Junsong Jin A.A.Churakova Xinyun Wang State Key Laboratory of Materials Processing and Die & Mould Technology School of Materials Science and Engineering Huazhong University of Science and Technology State Key Laboratory of Advanced Design and Manufacturing Technology for Vehicle Hunan University Institute of Molecule and Crystal Physics Ufa Federal Research Center RAS

The impact of different Ta contents on the mechanical properties and thermoplastic forming ability of in-situ Taparticle reinforced Zr–Cu–Al–Ni bulk metallic glass composites was studied. The composition(Zr55Cu30Al10-Ni5)94Ta6with the best comprehensive performance was chose for a systematic investigation into its thermoplastic behavior in the supercooled liquid region（SLR）, with quantitative analysis conducted by the strain rate sensitivity index and activation volume. The steady-state flow stress and the stress overshoot intensity were augmented with deformation temperature decreasing, strain rate increasing, and the addition of the secondary phase, leading to a transition from Newtonian to non-Newtonian flow regime. The addition of the secondary phase deteriorated the rheological properties of the material. To solve the problem that the Maxwell-Pulse constitutive model showed an inability to accurately describe the steady-state flow process. A modified constitutive relationship, introducing the effect of the volume fraction of Ta particles on viscosity and elastic modulus in the steady-state flow process which was ignored in Maxwell-pulse model, was established. The fitting results of the true stress-strain curves of the modified Maxwell-pulse constitutive model were in better agreement with the experimental date than those of the Maxwell-pulse constitutive model, with higher prediction accuracy. The modified constitutive model well predicted the thermoplastic deformation behavior of(Zr55Cu30Al10Ni5)*** influence mechanism of Ta particles on the flow behavior was explained that Ta particles increased the viscosity of amorphous matrix, thereby hindering its flow and ultimately leading to an increase in flow stress.

关键词： Bulk metallic glass composites Supercooled liquid region Thermoplastic deformation Constitutive model Influence mechanism

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Decorating crystalline YFe_(2-x)Al_(x) on the Mg_(60)La_(10)Ni_(20)Cu_(10) amorphous alloy as “hydrogen pump” to realize fast de/hydrogenation

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Journal of materials science & Technology 2024年第6期173卷 72-79页

作者： L.J.Huang H.Wang L.Z.Ouyang M.Zhu H.J.Lin School of Materials Science and Engineering Key Laboratory of Advanced Energy Storage Materials of Guangdong ProvinceSouth China University of TechnologyGuangzhou 510641China Institute of Advanced Wear&Corrosion Resistance and Functional Materials Jinan UniversityGuangzhou 510632China

Mg-based amorphous alloys are one of the potential hydrogen storage materials but suffer from sluggish dehydrogenation/hydrogenation(de/hydrogenation)*** this work,as a new strategy,a hydrogen pump is built on the surface of amorphous alloys to solve this *** milling crystalline YFe_(2-x)Al_(x) hydrogen storage alloy with Mg_(60)La_(10)Ni_(20)Cu_(10) amorphous alloy,fine crystalline particles were seeded on amorphous alloy powder to form a“strawberry”*** to the TEM observation,a metallurgical bonding boundary formed between the Mg-based amorphous matrix and the Y-Fe-Al crystalline *** microstructure and de/hydrogenation kinetics investigation,the“hydrogen pump”effect of the seeded crystalline alloy was confirmed,which makes it much easier for the hydrogen to dissociate on and diffuse through the surface of the Mg-based amorphous *** such effect,the H absorption rate of Mg_(60)La_(10)Ni_(20)Cu_(10) amorphous alloy became almost eight times faster and it absorbs ~2.8 wt.% in 1 h at 130℃ under 4.5 MPa-H_(2).Further,fast hydrogenation can even achieve at 70℃ and the low-temperature dehydrogenation kinetics of the amorphous hydride can be also greatly *** present work proves that surface modification is of great importance for obtaining Mg-based amorphous alloy with ideal hydrogen storage performance.

关键词： Hydrogen storage Mg-based amorphous alloy Hydrogen pump Composite structure

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Recent advances in porous structures for oxygen reduction reaction

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Progress in Natural science:materials International 2025年第1期35卷 83-97页

作者： Ying Chen Huawei Wang Yujing Li Beijing Key Laboratory of Construction Tailorable Advanced Functional Materials and Green Applications.School of Materials Science and Engineering Beijing Institute of Technology Fuel Cell Products Business Weichai Power Company Limited

As environmental concerns grow, there is a global shift from traditional fossil energy. Hydrogen fuel cells are gaining attention, but high material costs limit their adoption in large scale. The oxygen reduction reaction at the cathode of fuel cell, which dominates the electrochemical kinetics, relies mainly on platinum-group-metal(PGM) catalysts, hence research is focused on minimizing PGM or developing non-PGM catalysts. Porous materials possess unique physicochemical properties, and have shown great potential in advancing catalyst technology in fuel cells. This review summarizes the recent fundamental and technological advances of porous catalysts for oxygen reduction reactions including PGM and non-PGM catalysts, discusses the mechanisms underlying the enhanced catalytic activity through structural design and surface modification. It also highlights the comprehensive impact of porous materials in oxygen reduction reactions and membrane electrode assemblies,the main challenges, and provides perspectives on research of porous catalyst.

关键词： Oxygen reduction reaction

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