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High-efficiency sodium storage of Co_(0.85)Se/WSe_(2) encapsulated in N-doped carbon polyhedron via vacancy and heterojunction engineering 被引量:2
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作者 Ya Ru Pei Hong Yu Zhou +5 位作者 Ming Zhao Jian Chen Li Xin Ge Wei Zhang Chun Cheng Yang Qing Jiang 《Carbon Energy》 SCIE EI CAS CSCD 2024年第1期94-107,共14页
With the advantage of fast charge transfer,heterojunction engineering is identified as a viable method to reinforce the anodes'sodium storage performance.Also,vacancies can effectively strengthen the Na+adsorption... With the advantage of fast charge transfer,heterojunction engineering is identified as a viable method to reinforce the anodes'sodium storage performance.Also,vacancies can effectively strengthen the Na+adsorption ability and provide extra active sites for Na+adsorption.However,their synchronous engineering is rarely reported.Herein,a hybrid of Co_(0.85)Se/WSe_(2) heterostructure with Se vacancies and N-doped carbon polyhedron(CoWSe/NCP)has been fabricated for the first time via a hydrothermal and subsequent selenization strategy.Spherical aberration-corrected transmission electron microscopy confirms the phase interface of the Co_(0.85)Se/WSe_(2) heterostructure and the existence of Se vacancies.Density functional theory simulations reveal the accelerated charge transfer and enhanced Na+adsorption ability,which are contributed by the Co_(0.85)Se/WSe_(2) heterostructure and Se vacancies,respectively.As expected,the CoWSe/NCP anode in sodium-ion battery achieves outstanding rate capability(339.6 mAh g^(−1) at 20 A g^(−1)),outperforming almost all Co/W-based selenides. 展开更多
关键词 Co_(0.85)Se/WSe_(2)heterostructure density functional theory simulations N-doped carbon polyhedron Se vacancies sodium-ion batteries
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Optimizing high-coordination shell of Co-based single-atom catalysts for efficient ORR and zinc-air batteries 被引量:1
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作者 Yugang Qi Qing Liang +9 位作者 Kexin Song Xinyan Zhou Meiqi Liu Wenwen Li Fuxi Liu Zhou Jiang Xu Zou Zhongjun Chen Wei Zhang Weitao Zheng 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第8期306-314,I0007,共10页
Atom-level modulation of the coordination environment for single-atom catalysts(SACs)is considered as an effective strategy for elevating the catalytic performance.For the MNxsite,breaking the symmetrical geometry and... Atom-level modulation of the coordination environment for single-atom catalysts(SACs)is considered as an effective strategy for elevating the catalytic performance.For the MNxsite,breaking the symmetrical geometry and charge distribution by introducing relatively weak electronegative atoms into the first/second shell is an efficient way,but it remains challenging for elucidating the underlying mechanism of interaction.Herein,a practical strategy was reported to rationally design single cobalt atoms coordinated with both phosphorus and nitrogen atoms in a hierarchically porous carbon derived from metal-organic frameworks.X-ray absorption spectrum reveals that atomically dispersed Co sites are coordinated with four N atoms in the first shell and varying numbers of P atoms in the second shell(denoted as Co-N/P-C).The prepared catalyst exhibits excellent oxygen reduction reaction(ORR)activity as well as zinc-air battery performance.The introduction of P atoms in the Co-SACs weakens the interaction between Co and N,significantly promoting the adsorption process of ^(*)OOH,resulting in the acceleration of reaction kinetics and reduction of thermodynamic barrier,responsible for the increased intrinsic activity.Our discovery provides insights into an ultimate design of single-atom catalysts with adjustable electrocatalytic activities for efficient electrochemical energy conversion. 展开更多
关键词 ELECTROCATALYTIC Oxygen reduction reaction Single atom catalyst Shell coordination optimization
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Targeted regeneration and upcycling of spent graphite by defect‐driven tin nucleation 被引量:1
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作者 Zhiheng Cheng Zhiling Luo +7 位作者 Hao Zhang Wuxing Zhang Wang Gao Yang Zhang Long Qie Yonggang Yao Yunhui Huang Kun Kelvin Fu 《Carbon Energy》 SCIE EI CAS CSCD 2024年第4期91-103,共13页
The recycling of spent batteries has become increasingly important owing to their wide applications,abundant raw material supply,and sustainable development.Compared with the degraded cathode,spent anode graphite ofte... The recycling of spent batteries has become increasingly important owing to their wide applications,abundant raw material supply,and sustainable development.Compared with the degraded cathode,spent anode graphite often has a relatively intact structure with few defects after long cycling.Yet,most spent graphite is simply burned or discarded due to its limited value and inferior performance on using conventional recycling methods that are complex,have low efficiency,and fail in performance restoration.Herein,we propose a fast,efficient,and“intelligent”strategy to regenerate and upcycle spent graphite based on defect‐driven targeted remediation.Using Sn as a nanoscale healant,we used rapid heating(~50 ms)to enable dynamic Sn droplets to automatically nucleate around the surface defects on the graphite upon cooling owing to strong binding to the defects(~5.84 eV/atom),thus simultaneously achieving Sn dispersion and graphite remediation.As a result,the regenerated graphite showed enhanced capacity and cycle stability(458.9 mAh g^(−1) at 0.2 A g^(−1) after 100 cycles),superior to those of commercial graphite.Benefiting from the self‐adaption of Sn dispersion,spent graphite with different degrees of defects can be regenerated to similar structures and performance.EverBatt analysis indicates that targeted regeneration and upcycling have significantly lower energy consumption(~99%reduction)and near‐zero CO_(2) emission,and yield much higher profit than hydrometallurgy,which opens a new avenue for direct upcycling of spend graphite in an efficient,green,and profitable manner for sustainable battery manufacture. 展开更多
关键词 battery recycling spent graphite targeted regeneration upcycling graphite
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Negative Poisson's Ratios of Layered Materials by First-Principles High-Throughput Calculations
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作者 赵汉章 蔡雨欣 +3 位作者 梁兴昊 周琨 邹洪帅 张立军 《Chinese Physics Letters》 SCIE EI CAS CSCD 2023年第12期73-78,共6页
Auxetic two-dimensional(2D)materials,known from their negative Poisson's ratios(NPRs),exhibit the unique property of expanding(contracting)longitudinally while being laterally stretched(compressed),contrary to typ... Auxetic two-dimensional(2D)materials,known from their negative Poisson's ratios(NPRs),exhibit the unique property of expanding(contracting)longitudinally while being laterally stretched(compressed),contrary to typical materials.These materials offer improved mechanical characteristics and hold great potential for applications in nanoscale devices such as sensors,electronic skins,and tissue engineering.Despite their promising attributes,the availability of 2D materials with NPRs is limited,as most 2D layered materials possess positive Poisson's ratios.In this study,we employ first-principles high-throughput calculations to systematically explore Poisson's ratios of 40 commonly used 2D monolayer materials,along with various bilayer structures.Our investigation reveals that BP,GeS and GeSe exhibit out-of-plane NPRs due to their hinge-like puckered structures.For 1T-type transition metal dichalcogenides such as M X_(2)(M=Mo,W;X=S,Se,Te)and transition metal selenides/halides the auxetic behavior stems from a combination of geometric and electronic structural factors.Notably,our findings unveil V_(2)O_(5) as a novel material with out-of-plane NPR.This behavior arises primarily from the outward movement of the outermost oxygen atoms triggered by the relaxation of strain energy under uniaxial tensile strain along one of the in-plane directions.Furthermore,our computations demonstrate that Poisson's ratio can be tuned by varying the bilayer structure with distinct stacking modes attributed to interlayer coupling disparities.These results not only furnish valuable insights into designing 2D materials with a controllable NPR but also introduce V_(2)O_(5) as an exciting addition to the realm of auxetic 2D materials,holding promise for diverse nanoscale applications. 展开更多
关键词 RELAXATION attributed DIRECTIONS
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Role of self-assembled molecules’anchoring groups for surface defect passivation and dipole modulation in inverted perovskite solar cells
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作者 Xiaoyu Wang Muhammad Faizan +3 位作者 Kun Zhou Xinjiang Wang Yuhao Fu Lijun Zhang 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第10期108-115,共8页
Inverted perovskite solar cells have gained prominence in industrial advancement due to their easy fabrication,low hysteresis effects,and high stability.Despite these advantages,their efficiency is currently limited b... Inverted perovskite solar cells have gained prominence in industrial advancement due to their easy fabrication,low hysteresis effects,and high stability.Despite these advantages,their efficiency is currently limited by excessive defects and poor carrier transport at the perovskite-electrode interface,particularly at the buried interface between the perovskite and transparent conductive oxide(TCO).Recent efforts in the perovskite community have focused on designing novel self-assembled molecules(SAMs)to improve the quality of the buried interface.However,a notable gap remains in understanding the regulation of atomic-scale interfacial properties of SAMs between the perovskite and TCO interfaces.This understanding is crucial,particularly in terms of identifying chemically active anchoring groups.In this study,we used the star SAM([2-(9H-carbazol-9-yl)ethyl]phosphonic acid)as the base structure to investigate the defect passivation effects of eight common anchoring groups at the perovskite-TCO interface.Our findings indicate that the phosphonic and boric acid groups exhibit notable advantages.These groups fulfill three key criteria:they provide the greatest potential for defect passivation,exhibit stable adsorption with defects,and exert significant regulatory effects on interface dipoles.Ionized anchoring groups exhibit enhanced passivation capabilities for defect energy levels due to their superior Lewis base properties,which effectively neutralize local charges near defects.Among various defect types,iodine vacancies are the easiest to passivate,whereas iodine-substituted lead defects are the most challenging to passivate.Our study provides comprehensive theoretical insights and inspiration for the design of anchoring groups in SAMs,contributing to the ongoing development of more efficient inverted perovskite solar cells. 展开更多
关键词 inverted perovskite solar cell defect passivation self-assembled molecule interface engineering first-principles calculation
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Thin-walled and large-sized magnesium alloy die castings for passenger car cockpit:Application,materials,and manufacture
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作者 Lei Zhan Yu-meng Sun +6 位作者 Yang Song Chun-hua Kong Kai Ma Bai-xin Dong Hong-yu Yang Shi-li Shu Feng Qiu 《China Foundry》 SCIE EI CAS CSCD 2024年第5期525-545,共21页
In order to effectively reduce energy consumption and increase range mile,new energy vehicles represented by Tesla have greatly aroused the application of integrated magnesium(Mg)alloy die casting technology in automo... In order to effectively reduce energy consumption and increase range mile,new energy vehicles represented by Tesla have greatly aroused the application of integrated magnesium(Mg)alloy die casting technology in automobiles.Previously,the application of Mg alloys in automobiles,especially in automotive cockpit components,is quite extensive,while it has almost disappeared for a period of time due to its relatively high cost,causing a certain degree of information loss in the application technology of Mg alloy parts in automobiles.The rapid development of automotive technology has led to a higher requirement for the automotive components compared with those traditional one.Therefore,whatever the components themselves,or the Mg alloy materials and die casting process have to face an increasing challenge,needing to be upgraded.In addition,owing to its high integration characteristics,the application of Mg alloy die casting technology in large-sized and thin-walled automotive parts has inherent advantages and needs to be expanded urgently.Indeed,it necessitates exploring advance Mg alloys and new product structures and optimizing die casting processes.This article summarizes and analyzes the development status of thin-walled and large-sized die casting Mg alloy parts in passenger car cockpit and corresponding material selection methods,die casting processes as well as mold design techniques.Furthermore,this work will aid researchers in establishing a comprehensive understanding of the manufacture of thin-walled and large-sized die casting Mg alloy parts in automobile cockpit.It will also assist them in developing new Mg alloys with improved comprehensive performance and new processes to meet the high requirements for die casting automotive components. 展开更多
关键词 Mg alloys thin wall large size automotive part die casting
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Moiré superlattices arising from growth induced by screw dislocations in layered materials
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作者 田伏钰 Muhammad Faizan +2 位作者 贺欣 孙远慧 张立军 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第7期72-77,共6页
Moiré superlattices(MSLs) are modulated structures produced from homogeneous or heterogeneous two-dimensional layers stacked with a twist angle and/or lattice mismatch. Enriching the methods for fabricating MSL a... Moiré superlattices(MSLs) are modulated structures produced from homogeneous or heterogeneous two-dimensional layers stacked with a twist angle and/or lattice mismatch. Enriching the methods for fabricating MSL and realizing the unique emergent properties are key challenges in its investigation. Here we recommend that the spiral dislocation driven growth is another optional method for the preparation of high quality MSL samples. The spiral structure stabilizes the constant out-of-plane lattice distance, causing the variations in electronic and optical properties. Taking SnS_(2) MSL as an example, we find prominent properties including large band gap reduction(~ 0.4 e V) and enhanced optical activity. Firstprinciples calculations reveal that these unusual properties can be ascribed to the locally enhanced interlayer interaction associated with the Moiré potential modulation. We believe that the spiral dislocation driven growth would be a powerful method to expand the MSL family and broaden their scope of application. 展开更多
关键词 Moirésuperlattices interlayer interaction spiral dislocation layered materials
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Growth Control of Quasi-two-dimensional Perovskites:Structure-dependent Exciton and Charge Behavior
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作者 DONG Wei LI Jing +2 位作者 YIN Wenxu ZHANG Xiaoyu ZHENG Weitao 《发光学报》 EI CAS CSCD 北大核心 2024年第11期1767-1781,共15页
While three-dimensional perovskites have high defect tolerance and an adjustable bandgap,their charges tend to be free rather than forming excitons,making them unsuitable for use in efficient light-emitting diodes(LED... While three-dimensional perovskites have high defect tolerance and an adjustable bandgap,their charges tend to be free rather than forming excitons,making them unsuitable for use in efficient light-emitting diodes(LEDs).Rather,quasi-two-dimensional(Q-2D)perovskites offer high photoluminescence quantum yield along with the advantages of bulk perovskites,making them ideal for high-performance LEDs.In Q-2D perovskites,the structure(which includes factors like crystal orientation,phase distribution,and layer thickness)directly influences how excitons and charge carriers behave within the material.Growth control techniques,such as varying the synthesis conditions or employing methods,allow for fine-tuning the structural characteristics of these materials,which in turn affect exciton dynamics and charge transport.This review starts with a description of the basic properties of Q-2D perovskites,examines crystal growth in solution,explains how structure affects energy transfer behavior,and concludes with future directions for Q-2D perovskite LEDs.By understanding and optimizing the structure-dependent behavior,researchers can better control exciton dynamics and charge transport,which are crucial for enhancing the performance of optoelectronic devices like solar cells and LEDs. 展开更多
关键词 quasi-two-dimensional perovskites light-emitting diodes growth control energy transfer
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Compressive property and energy absorption characteristic of interconnected porous Mg-Zn-Y alloys with adjusting Y addition
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作者 J.A.Liu S.J.Liu +3 位作者 B.Wang W.B.Sun X.J.Liu Z.W.Han 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第1期171-185,共15页
In this study,interconnected porous Mg-2Zn-xY alloys with different phase compositions were prepared by various Y additions(x=0.4,3,and 6 wt.%)to adjust the compressive properties and energy absorption characteristics... In this study,interconnected porous Mg-2Zn-xY alloys with different phase compositions were prepared by various Y additions(x=0.4,3,and 6 wt.%)to adjust the compressive properties and energy absorption characteristics.Several characterization methods were then applied to identify the microstructure of the porous Mg-Zn-Y and describe the details of the second phase.Compressive tests were performed at room temperature(RT),200℃,and 300℃to study the impact of the Y addition and testing temperature on the compressive properties of the porous Mg-Zn-Y.The experimental results showed that a high Y content promotes a microstructure refinement and increases the volume fraction of the second phase.When the Y content increases,different Mg-Zn-Y ternary phases appear:I-phase(Mg_(3)Zn_(6)Y),W-phase(Mg_(3)Zn_(3)Y_(2)),and LPSO phase(Mg_(12)ZnY).When the Y content ranges between 0.4%and 6%,the compressive strength increases from 6.30MPa to 9.23 MPa,and the energy absorption capacity increases from 7.33 MJ/m^(3)to 10.97 MJ/m^(3)at RT,which is mainly attributed to the phase composition and volume fraction of the second phase.However,the average energy absorption efficiency is independent of the Y content.In addition,the compressive deformation behaviors of the porous Mg-Zn-Y are altered by the testing temperature.The compressive strength and energy absorption capacity of the porous Mg-Zn-Y decrease due to the softening effect of the high temperature on the struts.The deformation behaviors at different temperatures are finally observed to reflect the failure mechanisms of the struts. 展开更多
关键词 Porous magnesium Rare earth elements Microstructure Compressive behavior Energy absorption characteristic
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Synergistic effect of carbon nanotube and encapsulated carbon layer enabling high-performance SnS_2-based anode for lithium storage
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作者 Chunwei Dong Yongjin Xia +7 位作者 Zhijiang Su Zhihua Han Yang Dong Jingyun Chen Fei Hao Qiyao Yu Qing Jiang Jiaye Ye 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第10期700-709,I0015,共11页
Tin disulfide(SnS_(2)),due to large interlayer spacing and high theoretical capacity,is regarded as a prospective anode material for lithium-ion batteries.Nevertheless,the poor electron conductivity of SnS_(2) and hug... Tin disulfide(SnS_(2)),due to large interlayer spacing and high theoretical capacity,is regarded as a prospective anode material for lithium-ion batteries.Nevertheless,the poor electron conductivity of SnS_(2) and huge volumetric change during the lithiation/delithiation process lead to a rapid capacity decay of the battery,hindering its commercialization.To address these issues,herein,SnS_(2) is in-situ grown on the surface of carbon nanotubes(CNT)and then encapsulated with a layer of porous amorphous carbon(CNT/SnS_(2)@C)by simple solvothermal and further carbonization treatment.The synergistic effect of CNT and porous carbon layer not only enhances the electrical co nductivity of SnS_(2) but also limits the huge volumetric change to avoid the pulverization and detachment of SnS_(2).Density functional theo ry calculations show that CNT/SnS_(2)@C has high Li^(+)adsorption and lithium storage capacity achieving high reaction kinetics.Consequently,cells with the CNT/SnS_(2)@C anode exhibit a high lithium storage capacity of 837mAh/g after 100 cycles at 0.1 A/g and retaining a capacity of 529.8 mAh/g under 1.0 A/g after 1000 cycles.This study provides a fundamental understanding of the electrochemical processes and beneficial guidance to design high-performance SnS_(2)-based anodes for LIBs. 展开更多
关键词 Lithium-ion batteries Porous amorphous carbon Carbon nanotubes SnS_(2)-based anode Density functional theory calculations
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Exploring the role of iron in Fe_(5)Ni_(4)S_(8)toward oxygen evolution through modulation of electronic orbital occupancy
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作者 Zhengyan Du Zeshuo Meng +7 位作者 Haoteng Sun Yifan Li Chao Jiang Yaxin Li Xiaoying Hu Yi Cui Shansheng Yu Hongwei Tian 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第5期52-62,共11页
Ni-Fe-based catalysts are considered to be among the most active catalysts for the oxygen evolution reaction(OER)under alkaline conditions,with Fe playing a crucial role.However,Fe leaching occurs during the reaction ... Ni-Fe-based catalysts are considered to be among the most active catalysts for the oxygen evolution reaction(OER)under alkaline conditions,with Fe playing a crucial role.However,Fe leaching occurs during the reaction due to thermodynamic instability,which has resulted in conflicting reports within the literature regarding its role.To clarify this point,we propose a strategy consisting of modulating the electronic orbital occupancy to suppress the extensive loss of Fe atoms during the OER process.Theoretical calculations,in-situ X-ray photoelectron spectroscopy,molecular dynamics simulations,and a series of characterization showed that the stable presence of Fe not only accelerates the electron transfer process but also optimizes the reaction barriers of the oxygen evolution intermediates,promoting the phase transition of Fe_(5)Ni_(4)S_(8)to highly active catalytic species.The modulated Fe_(5)Ni_(4)S_(8)-based pre-catalysts exhibit improved OER activity and long-term durability.This study provides a novel perspective for understanding the role of Fe in the OER process. 展开更多
关键词 Oxygenevolution Fe_(5)Ni_(4)S_(8) Electronic orbital occupancy modulation Reconstruction dynamics
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The design and engineering strategies of metal tellurides for advanced metal-ion batteries
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作者 Wenmiao Zhao Xiaoyuan Shi +3 位作者 Bo Liu Hiroshi Ueno Ting Deng Weitao Zheng 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第2期579-598,I0013,共21页
Owning various crystal structures and high theoretical capacity,metal tellurides are emerging as promising electrode materials for high-performance metal-ion batteries(MBs).Since metal telluride-based MBs are quite ne... Owning various crystal structures and high theoretical capacity,metal tellurides are emerging as promising electrode materials for high-performance metal-ion batteries(MBs).Since metal telluride-based MBs are quite new,fundamental issues raise regarding the energy storage mechanism and other aspects affecting electrochemical performance.Severe volume expansion,low intrinsic conductivity and slow ion diffusion kinetics jeopardize the performance of metal tellurides,so that rational design and engineering are crucial to circumvent these disadvantages.Herein,this review provides an in-depth discussion of recent investigations and progresses of metal tellurides,beginning with a critical discussion on the energy storage mechanisms of metal tellurides in various MBs.In the following,recent design and engineering strategies of metal tellurides,including morphology engineering,compositing,defect engineering and heterostructure construction,for high-performance MBs are summarized.The primary focus is to present a comprehensive understanding of the structural evolution based on the mechanism and corresponding effects of dimension control,composition,electron configuration and structural complexity on the electrochemical performance.In closing,outlooks and prospects for future development of metal tellurides are proposed.This work also highlights the promising directions of design and engineering strategies of metal tellurides with high performance and low cost. 展开更多
关键词 Metal tellurides Metal-ion battery Energy storage mechanism Material design and engineering
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Hardening effect and precipitation evolution of an isothermal aged Mg-Sm based alloy 被引量:2
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作者 Kai Guan Chuang Li +7 位作者 Zhizheng Yang Yongsen Yu Qiang Yang Wenwen Zhang Zhiping Guan Cheng Wang Min Zha Huiyuan Wang 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2023年第12期4619-4627,共9页
The age-hardening behavior and precipitation evolution of an isothermal aged Mg-5Sm-0.6Zn-0.5Zr(wt.%) alloy have been systematically investigated by means of transmission electron microscopy(TEM) and atomic-resolution... The age-hardening behavior and precipitation evolution of an isothermal aged Mg-5Sm-0.6Zn-0.5Zr(wt.%) alloy have been systematically investigated by means of transmission electron microscopy(TEM) and atomic-resolution high-angle annular dark field scanning transmission electron microscopy(HAADF-STEM). The Vickers hardness of the present alloy increases first and then decreases with ageing time. The sample aged at 200 ℃ for 10 h exhibits a peak-hardness of 90.5 HV. In addition to the dominant β_(0)’ precipitate(orthorhombic,a = 0.642 nm, b = 3.336 nm and c = 0.521 nm) formed on {11-20}α planes, a certain number of γ’’ precipitate(hexagonal, a = 0.556 nm and c = 0.431 nm) formed on basal planes are also observed in the peak-aged alloy. Significantly, the basal γ’’ precipitate is more thermostable than prismatic β_(0)’ precipitate in the present alloy. β_(0)’ precipitates gradually coarsened and were even likely to transform into β_(1) phase(face centered cubic, a = 0.73 nm) with the increase of ageing time, which accordingly led to a gradual decrease in number density of precipitates and finally resulted in the decreased hardness and mechanical property in the over-aged alloys. 展开更多
关键词 Magnesium alloys Ageing treatment Microstructure characterization Age-hardening effect PRECIPITATES
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Simultaneous refinement of α-Mg grains and β-Mg_(17)Al_(12) in Mg-Al based alloys via heterogeneous nucleation on Al_(8)Mn_(4)Sm 被引量:1
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作者 Jun-Chen Chen Mei-Xuan Li +4 位作者 Zhi-Yang Yu Zhao-Yuan Meng Cheng Wang Zhi-Zheng Yang Hui-Yuan Wang 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2023年第1期348-360,共13页
Due to the significant differences in the formation temperature and crystal structure between the primaryα-Mg and eutecticβ-Mg_(17)Al_(12),it is a great challenge to achieve simultaneous refinement of the primary an... Due to the significant differences in the formation temperature and crystal structure between the primaryα-Mg and eutecticβ-Mg_(17)Al_(12),it is a great challenge to achieve simultaneous refinement of the primary and eutectic phases in Mg-Al based alloys via heterogeneous nucleation.Surprisingly,we found that theα-Mg andβ-Mg_(17)Al_(12) in the AZ80 alloy can be simultaneously refined after 0.2 wt.%Sm addition,with the grain size decreasing from∼217±15μm to∼170±10μm and theβ-Mg_(17)Al_(12) morphology changing from a typical continuous network to a nod-like or spherical structure.The simultaneous refinement mechanism is investigated through solidification simulation,transmission electron microscopy(TEM),and differential thermal analysis(DTA).In the AZ80-0.2Sm alloy,many Al8Mn4Sm particles can be observed near the center of theα-Mg grains or inside theβ-Mg_(17)Al_(12).Crystallographic calculations further reveal that the Al8Mn4Sm has good crystallographic matching with both theα-Mg andβ-Mg_(17)Al_(12),so it possesses the potency to serve as heterogeneous nucleation sites for both phases.The promoted heterogeneous nucleation on the Al8Mn4Sm decreases the undercooling required by the nucleation of the primary and eutectic phases,which enhances the heterogeneous nucleation rate,thus causing the simultaneous refinement of theα-Mg andβ-Mg_(17)Al_(12).The orientation relationships between the Al8Mn4Sm and Mg/Mg_(17)Al_(12) are identified,which are[1210]_(Mg)//[010]_(Al8Mn4Sm),(1010)_(Mg)//(301)_(Al8Mn4Sm) and[112]_(Mg_(17)Al_(12))//[010]_(Al8Mn4Sm),(110)_(Mg_(17)Al_(12))//(301)_(Al8Mn4Sm),respectively.Furthermore,the refinement of theβ-Mg_(17)Al_(12) accelerates its dissolution during the solution treatment,which is beneficial for cost saving in industrial applications.Other Al8Mn4RE compounds such as Al8Mn4Y might have the same positive effect on the simultaneous refinement due to the similar physicochemical properties of rare earth elements.This work not only proves the possibility of simultaneously refining the primary and eutectic phases in Mg-Al based alloys via heterogeneous nucleation,but also provides new insights into the development of refiners for cast Mg alloys. 展开更多
关键词 Magnesium alloys Microstructure refinement Primaryα-Mg Eutecticβ-Mg_(17)Al_(12) Rare earth Heterogeneous nucleation
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MXene-Based Quantum Dots Optimize Hydrogen Production via Spontaneous Evolution of Cl-to O-Terminated Surface Groups 被引量:1
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作者 Yuhua Liu Xiaoyu Zhang +5 位作者 Wei Zhang Xin Ge Yan Wang Xu Zou Xinyan Zhou Weitao Zheng 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2023年第6期251-258,共8页
MXene quantum dots(MQDs)offer wide applications owing to the abundant surface chemistry,tunable energy-level structure,and unique properties.However,the application of MQDs in electrochemical energy conversion,includi... MXene quantum dots(MQDs)offer wide applications owing to the abundant surface chemistry,tunable energy-level structure,and unique properties.However,the application of MQDs in electrochemical energy conversion,including hydrogen evolution reaction(HER),remains to be realized,as it remains a challenge to precisely control the types of surface groups and tune the structure of energy levels in MQDs,owing to the high surface energy-induced strong agglomeration in post-processing.Consequently,the determination of the exact catalytically active sites and processes involved in such an electrocatalysis is challenging because of the complexity of the synthetic process and reaction conditions.Herein,we demonstrated the spontaneous evolution of the surface groups of the Ti_(2)CT_(x)MQDs(x:the content of O atom),i.e.,replacement of the-Cl functional groups by O-terminated ones during the cathode reaction.This process resulted in a low Gibbs free energy(0.26 eV)in HER.Our steady Ti_(2)CO_(x)/Cu_(2)O/Cu foam systems exhibited a low overpotential of 175 mV at 10 mA cm^(-2)in 1 M aq.KOH,and excellent operational stability over 165 h at a constant current density of-10 mA cm^(-2). 展开更多
关键词 HF free hydrogen evolution MXene quantum dots surface group
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Research Advances of Typical Two Dimensional Layered Thermoelectric Materials 被引量:1
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作者 Haihua HUANG Xiaofeng FAN 《Research and Application of Materials Science》 2020年第2期1-11,共11页
Thermoelectric technologies have caught our intense attention due to their ability of heat conversion into electricity.The considerable efforts have been taken to develop and enhance thermoelectric properties of mater... Thermoelectric technologies have caught our intense attention due to their ability of heat conversion into electricity.The considerable efforts have been taken to develop and enhance thermoelectric properties of materials over the past several decades.Recently,twodimensional layered materials are making the promise for potential applications of thermoelectric devices because of the excellent physical and structural properties.Here,a comprehensive coverage about recent progresses in thermoelectric properties of typical two dimensional(2D)layered materials,including the theoretical and experimental results,is provided.Moreover,the potential applications of 2D thermoelectric materials are also involved.These results indicate that the development of 2D thermoelectric materials take a key role in the flexible electronic devices with thermoelectric technologies. 展开更多
关键词 thermoelectric properties transport properties 2D layered materials figure of merit first-principle calculations
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Enhancing water-dissociation kinetics and optimizing intermediates adsorption free energy of cobalt phosphide via high-valence Zr incorporating for alkaline water electrolysis 被引量:1
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作者 Huafeng Fan Dongxu Jiao +6 位作者 Jinchang Fan Dewen Wang Bilal Zaman Wei Zhang Lei Zhang Weitao Zheng Xiaoqiang Cui 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第8期119-127,I0005,共10页
Developing high-efficiency electrocatalysts for hydrogen evolution reaction(HER) and oxygen evolution reaction(OER) is required to enhance the sluggish kinetics of water dissociation and optimize the adsorption free e... Developing high-efficiency electrocatalysts for hydrogen evolution reaction(HER) and oxygen evolution reaction(OER) is required to enhance the sluggish kinetics of water dissociation and optimize the adsorption free energy of reaction intermediates.Herein,we tackle this challenge by incorporating high-valence Zr into CoP(ZrxCo_(1-x)P),which significantly accelerates the elementary steps of water electrolysis.Theoretical calculations indicate that the appropriate Zr incorporation effectively expedites the sluggish H2O dissociation kinetics and optimizes the adsorption energy of reaction intermediates for boosting the alkaline water electrolysis.These are confirmed by the experimental results of Zr_(0.06)Co_(0.94)P catalyst that delivers exceptional electrochemical activity.The overpotentials at the current density of 10 mA cm^(-2)(j10) are only 62(HER) and 240 mV(OER) in alkaline media.Furthermore,the Zr_(0.06)Co_(0.94)P/CC‖Zr_(0.06)Co_(0.94)P/CC system exhibits superior overall water splitting activity(1.53 V/j10),surpassing most of the reported bifunctional catalysts.This high-valence Zr incorporation and material design methods explore new avenues for realizing high-performance non-noble metal electrocatalysts. 展开更多
关键词 DFT simulation Water electrolysis Cobalt phosphide High-valence Zr
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Designing high-efficiency light-to-thermal conversion materials for solar desalination and photothermal catalysis 被引量:1
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作者 Hanjin Jiang Xinghang Liu +5 位作者 Dewen Wang Zhenan Qiao Dong Wang Fei Huang Hongyan Peng Chaoquan Hu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第4期581-600,共20页
Light-to-thermal conversion materials(LTCMs)have been of great interest to researchers due to their impressive energy conversion capacity and wide range of applications in biomedical,desalination,and synergistic catal... Light-to-thermal conversion materials(LTCMs)have been of great interest to researchers due to their impressive energy conversion capacity and wide range of applications in biomedical,desalination,and synergistic catalysis.Given the limited advances in existing materials(metals,semiconductors,π-conjugates),researchers generally adopt the method of constructing complex systems and hybrid structures to optimize performance and achieve multifunctional integration.However,the development of LTCMs is still in its infancy as the physical mechanism of light-to-thermal conversion is unclear.In this review,we proposed design strategies for efficient LTCMs by analyzing the physical process of light-tothermal conversion.First,we analyze the nature of light absorption and heat generation to reveal the physical processes of light-to-thermal conversion.Then,we explain the light-to-thermal conversion mechanisms of metallic,semiconducting andπ-conjugated LCTMs,and propose new material design strategies and performance improvement methods.Finally,we summarize the challenges and prospects of LTCMs in emerging applications such as solar water evaporation and photothermal catalysis. 展开更多
关键词 Light-to-thermal conversion Solar energy conversion Material design Performance improvement Solar water evaporation Photothermal catalysis
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Ultrathin origami accordion-like structure of vacancy-rich graphitized carbon nitride for enhancing CO_(2) photoreduction 被引量:1
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作者 Guangri Jia Zhongxu Wang +8 位作者 Ming Gong Ying Wang Lu Hua Li Yilong Dong Lulu Liu Lei Zhang Jingxiang Zhao Weitao Zheng Xiaoqiang Cui 《Carbon Energy》 SCIE CSCD 2023年第4期94-104,共11页
Retaining the ultrathin structure of two-dimensional materials is very important for stabilizing their catalytic performances.However,aggregation and restacking are unavoidable,to some extent,due to the van der Waals ... Retaining the ultrathin structure of two-dimensional materials is very important for stabilizing their catalytic performances.However,aggregation and restacking are unavoidable,to some extent,due to the van der Waals interlayer interaction of two-dimensional materials.Here,we address this challenge by preparing an origami accordion structure of ultrathin twodimensional graphitized carbon nitride(oa-C_(3)N_(4))with rich vacancies.This novel structured oa-C_(3)N_(4) shows exceptional photocatalytic activity for the CO_(2) reduction reaction,which is 8.1 times that of the pristine C_(3)N_(4).The unique structure not only prevents restacking but also increases light harvesting and the density of vacancy defects,which leads to modification of the electronic structure,regulation of the CO_(2) adsorption energy,and a decrease in the energy barrier of the carbon dioxide to carboxylic acid intermediate reaction.This study provides a new avenue for the development of stable highperformance two-dimensional catalytic materials. 展开更多
关键词 C_(3)N_(4) CO_(2)photoreduction molecular modification PHOTOCATALYSTS solar energy conversion two-dimensional materials
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Evaluation of performance of machine learning methods in mining structure-property data of halide perovskite materials
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作者 Ruoting Zhao Bangyu Xing +2 位作者 Huimin Mu Yuhao Fu Lijun Zhang 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第5期28-35,共8页
With the rapid development of artificial intelligence and machine learning(ML)methods,materials science is rapidly entering the era of data-driven materials informatics.ML models serve as the most crucial component,cl... With the rapid development of artificial intelligence and machine learning(ML)methods,materials science is rapidly entering the era of data-driven materials informatics.ML models serve as the most crucial component,closely bridging material structure and material properties.There is a considerable difference in the prediction performance of different ML methods for material systems.Herein,we evaluated three categories(linear,kernel,and nonlinear methods)of models,with twelve ML algorithms commonly used in the materials field.In addition,halide perovskite was chosen as an example to evaluate the fitting performance of different models.We constructed a total dataset of 540 halide perovskites and 72 features,with formation energy and bandgap as target properties.We found that different categories of ML models show similar trends for different target properties.Among them,the difference between the models is enormous for the formation energy,with the coefficient of determination(R2)range 0.69-0.953.The fitting performance between the models is closer for bandgap,with the R^(2)range 0.941-0.997.The nonlinear-ensemble model shows the best fitting performance for both the formation energy and the bandgap.It shows that the nonlinear-ensemble model,constructed by combining multiple weak learners,effectively describes the nonlinear relationship between material features and target property.In addition,the extreme gradient boosting decision tree model shows the most superior results among all the models and searches for two new descriptors that are crucial for formation energy and bandgap.Our work provides useful guidance for the selection of effective machine learning methods in the data-mining studies of specific material systems. 展开更多
关键词 machine learning material informatics first-principles calculations halide perovskites
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