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Regulating photocatalytic overall water splitting of ferroelectric heterostructures by size effect

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Nano Research 2024年第9期17卷 8000-8006页

作者： Zixing Ye Daifu Yu Ruian Zhang Fei Qin Yiran Sun Jie Huang Zhanqi Zhou He Tian Gaorong Han Zhaohui Ren Gang Liu State Key laboratory of Silicon and advanced Semiconductor Materials School of Materials Science and EngineeringZhejiang UniversityHangzhou 310027China Shenyang National laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Center of Electron microscopy School of Materials Science and EngineeringZhejiang UniversityHangzhou 310027China

In the past decade,ferroelectric materials have been intensively explored as promising *** intriguing ability of ferroelectrics is to directly sperate the photogenerated electrons and holes,which is believed to arise from a spontaneous *** how polarization affects the photocatalytic performance is vital to design high-efficiency *** this work,we report a size effect of ferroelectric polarization on regulating the photocatalytic overall water splitting of SrTiO_(3)/PbTiO_(3)nanoplate heterostructures for the first *** was realized hydrothermally by controlling the thickness and thus spontaneous polarization strength of single-crystal and single-domain PbTiO_(3)nanoplates,which served as the substrate for selective heteroepitaxial growth of SrTiO_(3).An enhancement of 22 times in the photocatalytic overall water splitting performance of the heterostructures has been achieved when the average thickness of the nanoplate increases from 30 to 107 nm.A combined experimental investigation revealed that the incompletely compensated depolarization filed is the dominated driving force for the photogenerated carrier separation within heterostructures,and its increase with the thickness of the nanoplates accounts for the enhancement of photocatalytic ***,the concentration of oxygen vacancies for negative polarization compensation has been found to grow as the thickness of the nanoplates increases,which promotes oxygen evolution reaction and reduces the stoichiometric ratio of H_(2)/O_(2).These findings may provide the opportunity to design and develop high-efficiency ferroelectric photocatalysts.

关键词： single-domain nanoplates size effect ferroelectric polarization screening photocatalytic overall water splitting

Cationic ordering transition in oxygen-redox layered oxide cathodes

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Carbon Energy 2024年第1期6卷 197-206页

作者： Xinyan Li Ang Gao Qinghua Zhang Hao Yu Pengxiang Ji Dongdong Xiao Xuefeng Wang Dong Su Xiaohui Rong Xiqian Yu Hong Li Yong-Sheng Hu Lin Gu Beijing National laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijingChina College of Materials Science and Opto-Electronic Technology University of Chinese Academy of SciencesBeijingChina Beijing National Center for Electron microscopy and laboratory of advanced Materials School of Materials Science and EngineeringTsinghua UniversityBeijingChina Beijing advanced Innovation Center for Materials Genome Engineering Huairou DivisionInstitute of PhysicsChinese Academy of SciencesBeijingChina

Understanding the structural origin of the competition between oxygen 2p and transition-metal 3d orbitals in oxygen-redox(OR)layered oxides is eminently desirable for exploring reversible and high-energy-density Li/Na-ion ***,we reveal the correlation between cationic ordering transition and OR degradation in ribbon-ordered P3-Na_(0.6)Li_(0.2)Mn_(0.8)O_(2) via in situ structural *** two different voltage windows,the OR capacity can be improved approximately twofold when suppressing the in-plane cationic ordering *** find that the intralayer cationic migration is promoted by electrochemical reduction from Mn^(4+)to Jahn–Teller Mn^(3+)and the concomitant NaO_(6) stacking transformation from triangular prisms to octahedra,resulting in the loss of ribbon ordering and electrochemical ***-principles calculations reveal that Mn^(4+)/Mn^(3+)charge ordering and alignment of the degenerate eg orbital induce lattice-level collective Jahn–Teller distortion,which favors intralayer Mn-ion migration and thereby accelerates OR *** findings unravel the relationship between in-plane cationic ordering and OR reversibility and highlight the importance of superstructure protection for the rational design of reversible OR-active layered oxide cathodes.

关键词： cationic ordering layered oxide cathodes oxygen redox sodium-ion batteries

A highly sensitive LITES sensor based on a multi-pass cell with dense spot pattern and a novel quartz tuning fork with low frequency

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Opto-Electronic Advances 2024年第3期7卷 26-34页

作者： Yahui Liu Shunda Qiao Chao Fang Ying He Haiyue Sun Jian Liu Yufei Ma National Key laboratory of Science and Technology on Tunable Laser Harbin Institute of TechnologyHarbin 150000China Zhengzhou Research Institute Harbin Institute of TechnologyZhengzhou 450000China advanced microscopy and Instrumentation Research Center School of Instrumentation Science and EngineeringHarbin Institute of TechnologyHarbin 150080China.

A highly sensitive light-induced thermoelectric spectroscopy(LITES)sensor based on a multi-pass cell(MPC)with dense spot pattern and a novel quartz tuning fork(QTF)with low resonance frequency is reported in this *** erbi-um-doped fiber amplifier(EDFA)was employed to amplify the output optical power so that the signal level was further *** optical path length(OPL)and the ratio of optical path length to volume(RLV)of the MPC is 37.7 m and 13.8 cm^(-2),respectively.A commercial QTF and a self-designed trapezoidal-tip QTF with low frequency of 9461.83 Hz were used as the detectors of the sensor,*** target gas selected to test the performance of the system was acetylene(C2H2).When the optical power was constant at 1000 mW,the minimum detection limit(MDL)of the C2H2-LITES sensor can be achieved 48.3 ppb when using the commercial QTF and 24.6 ppb when using the trapezoid-al-tip *** improvement of the detection performance by a factor of 1.96 was achieved after replacing the commer-cial QTF with the trapezoidal-tip QTF.

关键词： light-induced thermoelectric spectroscopy quartz tuning fork multi-pass cell gas sensing

Critical precipitation behavior of MnTe inclusions in resulfurized steels during solidification

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International Journal of Minerals,Metallurgy and Materials 2024年第8期31卷 1849-1857页

作者： Xiangyu Xu Lu Zhang Zifei Wang Qianren Tian Jianxun Fu Xuemin Wang Center for advanced Solidification Technology(CAST) School of Materials Science and EngineeringShanghai UniversityShanghai 200444China State Key laboratory of advanced Special Steel Shanghai UniversityShanghai 200444China Collaborative Innovation Center of Steel Technology University of Science and Technology BeijingBeijing 100083China Yangjiang Branch Guangdong Laboratory for Materials Science and Technology(Yangjiang)Advanced Alloys LaboratoryYangjiang 529500China

Te treatment is an effective method for modifying sulfide inclusions,and MnTe precipitation has an important effect on thermal brittleness and steel corrosion *** most actual industrial applications of Te treatment,MnTe precipitation is *** critical precipitation behavior of MnTe inclusions was investigated through scanning electron microscopy,transmission electron microscopy,machine learning,and first-principles *** preferentially precipitated at the container mouth for sphere-like sulfides and at the interface between MnS grain boundaries and steel matrix for rod-like *** MnS/MnTe interface was semicoherent.A composition transition zone with a rock-salt structure exhibiting periodic changes existed to maintain the semicoherent *** critical precipitation behavior of MnTe inclusions in resulfurized steels involved three stages at varying ***,Mn(S,Te)precipitated during ***,MnTe with a rock-salt structure precipitated from Mn(S,Te).Third,MnTe with a hexagonal NiAs structure transformed from the rock-salt *** solubility of Te in MnS decreased with decreasing *** critical precipitation behavior of MnTe inclusions in resulfurized steels was related to the MnS precipitation *** the increase in MnS precipitation temperature,the critical Te/S weight ratio *** consideration of the cost-effectiveness of Te addition for industrial production,the Te content in resulfurized steels should be controlled in accordance with MnS precipitation temperature and S content.

关键词： resulfurized steels modification of inclusion manganese telluride precipitation

Recent progress in visualization and digitization of coherent transformation structures and application in high-strength steel

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International Journal of Minerals,Metallurgy and Materials 2024年第6期31卷 1298-1310页

作者： Xuelin Wang Zhenjia Xie Xiucheng Li Chengjia Shang Collaborative Innovation Center of Steel Technology University of Science and Technology BeijingBeijing 100083China State Key laboratory for advanced Metals and Materials University of Science and Technology BeijingBeijing 100083China Yangjiang Branch Guangdong Laboratory for Materials Science and Technology(Yangjiang Advanced Alloys Laboratory)Yangjiang 529500China

High-strength steels are mainly composed of medium-or low-temperature microstructures,such as bainite or martensite,with coherent transformation *** type of microstructure has a high density of dislocations and fine crystallographic structural units,which ease the coordinated matching of high strength,toughness,and ***,given its excellent welding perform-ance,high-strength steel has been widely used in major engineering constructions,such as pipelines,ships,and ***,visual-ization and digitization of the effective units of these coherent transformation structures using traditional methods(optical microscopy and scanning electron microscopy)is difficult due to their complex ***,the establishment of quantitative relationships with macroscopic mechanical properties and key process parameters presents additional *** article reviews the latest progress in microstructural visualization and digitization of high-strength steel,with a focus on the application of crystallographic methods in the development of high-strength steel plates and *** obtained the crystallographic data(Euler angle)of the transformed microstruc-tures through electron back-scattering diffraction and combined them with the calculation of inverse transformation from bainite or martensite to austenite to determine the reconstruction of high-temperature parent austenite and orientation relationship(OR)during con-tinuous cooling ***,visualization of crystallographic packets,blocks,and variants based on actual OR and digit-ization of various grain boundaries can be effectively completed to establish quantitative relationships with alloy composition and key process parameters,thereby providing reverse design guidance for the development of high-strength steel.

关键词： high-strength steel microstructure visualization digitization quantification mechanical properties

Application of three-dimensional electron diffraction in structure determination of zeolites

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Chinese Journal of Structural Chemistry 2024年第4期43卷 39-47页

作者： Yuhang Li Yang Ling Yanhang Ma School of Physical Science and Technology&Shanghai Key laboratory of High-resolution Electron microscopy ShanghaiTech UniversityShanghai201210China

Zeolites have received great attention due to their wide applications in various fields such as catalysis,adsorp-tion/separation,ion exchange,*** the atomic crystal structure of zeolites is crucial to understanding their functions and exploring their *** to the difficulty of synthesizing large single crystals,the structures of many zeolites cannot be solved using conventional single-crystal X-ray diffraction(SCXRD)***-dimensional electron diffraction(3D ED)has witnessed rapid development during the past decade and has shown its powerful ability in the structure determination of *** this review,we will briefly introduce the history of 3D ED and summarize recent advances in the application of 3D ED for the analysis of zeolite structures,along with several typical examples in this research field.

关键词： Electron diffraction Three-dimensional electron diffraction Zeolite Structure solution Electron crystallography

Electronic structure engineering of transition metal dichalcogenides for boosting hydrogen energy conversion electrocatalysts

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Chinese Physics B 2024年第9期33卷 13-28页

作者： Bing Hao Jingjing Guo Peizhi Liu Junjie Guo Key laboratory of Interface Science and Engineering in advanced Materials Ministry of EducationTaiyuan University of TechnologyTaiyuan 030024China

Electrocatalytic water splitting for hydrogen production is an appealing strategy to reduce carbon emissions and generate renewable *** promising process,however,is limited by its sluggish reaction kinetics and high-cost *** two-dimensional(2D)transition metal dichalcogenides(TMDCs)have presented great potential as electrocatalytic materials due to their tunable bandgaps,abundant defective active sites,and good chemical ***,phase engineering,defect engineering and interface engineering have been adopted to manipulate the electronic structure of TMDCs for boosting their exceptional catalytic ***,it is essential to clarify the local structure of catalytically active sites of TMDCs and their structural evolution in catalytic reactions using atomic resolution electron microscopy and the booming in situ technologies,which is beneficial for exploring the underlying reaction *** this review,the growth regulation,characterization,particularly atomic configurations of active sites in TMDCs are *** significant role of electron microscopy in the understanding of the growth mechanism,the controlled synthesis and functional optimization of 2D TMDCs are *** review will shed light on the design and synthesis of novel electrocatalysts with high performance,as well as prompt the application of advanced electron microscopy in the research of materials science.

关键词： TMDCs STEM hydrogen energy conversion active site identification

Kinetically and thermodynamically expediting elementary steps via high-valence Cr-incorporated of nickel selenide for water electrolysis

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Nano Research 2024年第3期17卷 1199-1208页

作者： Huafeng Fan Dongxu Jiao Jinchang Fan Dewen Wang Bilal Zaman Wei Zhang Lei Zhang Weitao Zheng Xiaoqiang Cui State Key laboratory of Automotive Simulation and Control School of Materials Science and EngineeringKey Laboratory of Automobile Materials of MOEJilin Provincial International Cooperation Key Laboratory of High-Efficiency Clean Energy MaterialsElectron Microscopy CenterJilin UniversityChangchun 130012China College of Chemistry Jilin UniversityChangchun 130012China

Designing high-performance electrocatalysts toward hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)is essential to reduce the activation barrier and optimize free adsorption energy of reactive ***,we report that incorporating high-valence Cr into NiSe_(2)(Cr_(x)Ni_(1-x)Se_(2))kinetically and thermodynamically expedites elementary steps of both HER and *** as-prepared Cr_(0.05)Ni_(0.95)Se_(2) catalyst displays excellent HER and OER activities,with low overpotentials of 89 and 272 mV at the current density of 10 mA·cm^(-2)(j10),respectively,and remains stable during operation for 30 h.A low cell voltage of only 1.59 V is required to drive j10 in alkaline *** situ Raman spectroscopy reveals that Cr incorporation facilitates the formation of NiOOH active species during the OER ***,theoretical explorations demonstrate that high-valence Cr incorporation efficiently accelerates water dissociation kinetics and improves H*adsorption during HER process,lowering the activation barrier of OER and optimizing the adsorption energy of oxygen-based intermediate,thus kinetically and thermodynamically enhancing the intrinsic performance of NiSe_(2) for over water *** strategy provides a new horizon to design transition metal based electrocatalysts in the clean energy field.

关键词： nickel selenide electrocatalytic water splitting high-valence Cr density functional theory(DFT)calculation

Micro-nanoarchitectonic of aluminum-hydrogel propellant with static stability and dynamic rheology

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Frontiers of Chemical Science and Engineering 2024年第4期18卷 87-96页

作者： Huiyan Guo Huaiyu Li Hongzhi Zhang Lun Pan Chengxiang Shi Kang Xue Xiangwen Zhang Ji-Jun Zou Key laboratory for advanced Fuel and Propellant of Ministry of Education School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China

The aluminum-water system is a promising propellant due to high energy and low signal characteristics,and the gel form is easier to store and *** this work,hydrogels of water and aluminum particles were prepared using the low-molecular-weight gellant *** various physical properties of gel systems,including the water loss rate,phase transition temperature,and centrifugal stability at different gellant and aluminum contents,were *** properties were assessed through shear thinning tests,thixotropy tests,strain sweep analysis,and frequency sweep *** microstructure of the gel was obtained through scanning electron microscopy *** results show that the aluminum-hydrogel network structure is composed of micron-scale aluminum and agarose nanosheets,and the unique micro-nanostructure endows the gel with excellent mechanical strength and thermal stability,which improve with increasing gellant and aluminum ***,the gel with 2% agarose and 20% aluminum had the best performance;the storage modulus reached 90647 Pa,which was within the linear viscoelastic region,and the maximum withstand pressure was 111.2 kPa,which was 118.8% greater than that of the pure ***,the gel demonstrates remarkable shear thinning behavior and can undergo gel-sol transformation upon shearing or heating to exceeding 114℃.

关键词： aluminum-water propellant gelled propellant rheological property mechanical strength