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学者姓名：郑坤
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Abstract ：
Single-atom Fe catalysts are considered as the promising catalysts for oxygen reduction reaction (ORR). However, the high electronegativity of the symmetrical coordination N atoms around Fe site generally results in too strong adsorption of *OOH intermediates on the active site, severely limiting the catalytic performance. Herein, a "heteroatom pair synergetic modulation" strategy is proposed to tailor the coordination environment and spin state of Fe sites, enabling breaking the shackles of unsuitable adsorption of intermediate products on the active centers toward a more efficient ORR pathway. The unsymmetrically Co and B heteroatomic coordinated Fe single sites supported on an N-doped carbon (FeBCo/NC) catalyst perform excellent ORR activity with high half-wave potential (E-1/2) of 0.891 V and a large kinetic current density (J(k)) of 60.6 mA cm(-2), which is several times better than those of commercial Pt/C catalysts. By virtue of in situ electrochemical impedance and synchrotron infrared spectroscopy, it is observed that the optimized Fe sites can effectively accelerate the evolution of O-2 into the *O intermediate, overcoming the sluggish OO bond cleavage of the *OOH intermediate, which is responsible for fast four-electron reaction kinetics.
Keyword ：
in situ electrochemical impedance in situ electrochemical impedance ORR ORR asymmetric coordination asymmetric coordination in situ synchrotron infrared spectroscopy in situ synchrotron infrared spectroscopy electrocatalysts electrocatalysts
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| GB/T 7714 | An, Qizheng , Zhang, Xu , Yang, Chenyu et al. Engineering Unsymmetrically Coordinated Fe Sites via Heteroatom Pairs Synergetic Contribution for Efficient Oxygen Reduction [J]. | SMALL , 2023 , 19 (49) . |
| MLA | An, Qizheng et al. "Engineering Unsymmetrically Coordinated Fe Sites via Heteroatom Pairs Synergetic Contribution for Efficient Oxygen Reduction" . | SMALL 19 . 49 (2023) . |
| APA | An, Qizheng , Zhang, Xu , Yang, Chenyu , Su, Hui , Zhou, Wanlin , Liu, Meihuan et al. Engineering Unsymmetrically Coordinated Fe Sites via Heteroatom Pairs Synergetic Contribution for Efficient Oxygen Reduction . | SMALL , 2023 , 19 (49) . |
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Abstract ：
As an implementation tool of data intensive scientific research methods, machine learning (ML) can effectively shorten the research and development (R&D) cycle of new materials by half or even more. ML shows great potential in the combination with other scientific research technologies, especially in the processing and classification of large amounts of material data from theoretical calculation and experimental characterization. It is very important to systematically understand the research ideas of material informatics to accelerate the exploration of new materials. Here, we provide a comprehensive introduction to the most commonly used ML modeling methods in material informatics with classic cases. Then, we review the latest progresses of prediction models, which focus on new processing-structure-properties-performance (PSPP) relationships in some popular material systems, such as perovskites, catalysts, alloys, two-dimensional materials, and polymers. In addition, we summarize the recent pioneering researches in innovation of material research technology, such as inverse design, ML interatomic potentials, and microtopography characterization assistance, as new research directions of material informatics. Finally, we comprehensively provide the most significant challenges and outlooks related to the future innovation and development in the field of material informatics. This review provides a critical and concise appraisal for the applications of material informatics, and a systematic and coherent guidance for material scientists to choose modeling methods based on required materials and technologies.
Keyword ：
features features materials informatics materials informatics machine learning machine learning modeling modeling materials materials
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| GB/T 7714 | Li, Chen , Zheng, Kun . Methods, progresses, and opportunities of materials informatics [J]. | INFOMAT , 2023 , 5 (8) . |
| MLA | Li, Chen et al. "Methods, progresses, and opportunities of materials informatics" . | INFOMAT 5 . 8 (2023) . |
| APA | Li, Chen , Zheng, Kun . Methods, progresses, and opportunities of materials informatics . | INFOMAT , 2023 , 5 (8) . |
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Abstract ：
The main aspects of material research: material synthesis, material structure, and material properties, are interrelated. Acquiring atomic structure information of electron beam sensitive materials by electron microscope, such as porous zeolites, organic-inorganic hybrid perovskites, metal-organic frameworks, is an important and challenging task. The difficulties in characterization of the structures will inevitably limit the optimization of their synthesis methods and further improve their performance. The emergence of integrated differential phase contrast scanning transmission electron microscopy (iDPC-STEM), a STEM characterization technique capable of obtaining images with high signal-to-noise ratio under lower doses, has made great breakthroughs in the atomic structure characterization of these materials. This article reviews the developments and applications of iDPC-STEM in electron beam sensitive materials, and provides an outlook on its capabilities and development.
Keyword ：
low dose low dose electron microscopic characterization electron microscopic characterization electron beam sensitive materials electron beam sensitive materials iDPC-STEM iDPC-STEM
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| GB/T 7714 | Wang, Hongyi , Liu, Linlin , Wang, Jiaxing et al. The Development of iDPC-STEM and Its Application in Electron Beam Sensitive Materials [J]. | MOLECULES , 2022 , 27 (12) . |
| MLA | Wang, Hongyi et al. "The Development of iDPC-STEM and Its Application in Electron Beam Sensitive Materials" . | MOLECULES 27 . 12 (2022) . |
| APA | Wang, Hongyi , Liu, Linlin , Wang, Jiaxing , Li, Chen , Hou, Jixiang , Zheng, Kun . The Development of iDPC-STEM and Its Application in Electron Beam Sensitive Materials . | MOLECULES , 2022 , 27 (12) . |
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Abstract ：
Polymeric carbon nitride (C3N4) is a very attractive candidate to produce photocatalytic hydrogen peroxide (H2O2) due to its low-cost, metal-free characteristics. However, the low efficiency would limit its development to higher yields because of insufficient light absorption and electron-hole separation. Here, we developed a simple method to anchor CN quantum dots (QDs) onto g-C3N4 nanosheets to form a homojunction structure (HJ-C3N4), which could improve photocatalytic performance largely without introducing metal elements. Its superior efficiency is a result of the band alignment by the homojunction structure providing excellent electron-hole separation and QDs providing suppressed recombination. Simultaneously, the light responsiveness of QDs endows a wide spectrum-responsive adsorption and enhances the adsorption intensity. The H2O2 yield of the HJ-C3N4 reached 115 mu mol L-1 h(-1) in pure water by visible light, which has an 8.6x higher production than g-C3N4 nanosheets. The material design of 0D/2D homojunction could be extended to other materials with specific band alignment.
Keyword ：
Band alignment Band alignment Carbon nitride Carbon nitride Quantum dots Quantum dots H2O2 H2O2 Homojunction Homojunction
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| GB/T 7714 | Ma, Peijie , Zhang, Xu , Wang, Cong et al. Band alignment of homojunction by anchoring CN quantum dots on g-C3N4 (0D/2D) enhance photocatalytic hydrogen peroxide evolution [J]. | APPLIED CATALYSIS B-ENVIRONMENTAL , 2022 , 300 . |
| MLA | Ma, Peijie et al. "Band alignment of homojunction by anchoring CN quantum dots on g-C3N4 (0D/2D) enhance photocatalytic hydrogen peroxide evolution" . | APPLIED CATALYSIS B-ENVIRONMENTAL 300 (2022) . |
| APA | Ma, Peijie , Zhang, Xu , Wang, Cong , Wang, Zhiwei , Wang, Kaiwen , Feng, Yibo et al. Band alignment of homojunction by anchoring CN quantum dots on g-C3N4 (0D/2D) enhance photocatalytic hydrogen peroxide evolution . | APPLIED CATALYSIS B-ENVIRONMENTAL , 2022 , 300 . |
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Abstract ：
Phase transition is a physical phenomenon that attracts great interest of researchers. Although the theory of second-order phase transitions is well-established, their atomic-scale dynamics in polycrystalline materials remains elusive. In this work, second-order phase transitions in polycrystalline Cu2Se at the transition temperature are directly observed by in situ aberration-corrected transmission electron microscopy. Phase transitions in microcrystalline Cu2Se start at the grain boundaries and extend inside the grains. This phenomenon is more pronounced in nanosized grains. Analysis of phase transitions in nanocrystalline Cu2Se with different grain boundaries demonstrates that grain boundary energy dominates unsynchronized phase transition behavior. This suggests that the energy of grain boundaries is the key factor influencing the energetic barrier for initiation of phase transition. The findings advance atomic-scale understanding of second-order phase transitions, which is crucial for the control of this process in polycrystalline materials.
Keyword ：
Se-2 Se-2 unsynchronized phase transition unsynchronized phase transition atomic-scale atomic-scale in situ transmission electron microscopy in situ transmission electron microscopy Cu Cu
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| GB/T 7714 | Yuan, Hua-Lei , Wang, Kaiwen , Hu, Hanwen et al. Atomic-Scale Observation of Grain Boundary Dominated Unsynchronized Phase Transition in Polycrystalline Cu2Se [J]. | ADVANCED MATERIALS , 2022 , 34 (40) . |
| MLA | Yuan, Hua-Lei et al. "Atomic-Scale Observation of Grain Boundary Dominated Unsynchronized Phase Transition in Polycrystalline Cu2Se" . | ADVANCED MATERIALS 34 . 40 (2022) . |
| APA | Yuan, Hua-Lei , Wang, Kaiwen , Hu, Hanwen , Yang, Lei , Chen, Jie , Zheng, Kun . Atomic-Scale Observation of Grain Boundary Dominated Unsynchronized Phase Transition in Polycrystalline Cu2Se . | ADVANCED MATERIALS , 2022 , 34 (40) . |
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Abstract ：
As a promising metal-free photocatalyst, graphitic carbon nitride (g-C3N4) is still limited by insufficient visible light absorption and rapid recombination of photogenerated carriers, resulting in low photocatalytic activity. Here, we adjusted the microstructure of the pristine bulk-g-C3N4 (PCN) and further loaded silver (Ag) nanoparticles. Abundant Ag nanoparticles were grown on the thin-layer g-C3N4 nanosheets (CNNS), and the Ag nanoparticles decorated g-C3N4 nanosheets (Ag@CNNS) were successfully synthesized. The thin-layer nanosheet-like structure was not only beneficial for the loading of Ag nanoparticles but also for the adsorption and activation of reactants via exposing more active sites. Moreover, the surface plasmon resonance (SPR) effect induced by Ag nanoparticles enhanced the absorption of visible light by narrowing the band gap of the substrate. Meanwhile, the composite band structure effectively promoted the separation and transfer of carriers. Benefiting from these merits, the Ag@CNNS reached a superior hydrogen peroxide (H2O2) yield of 120.53 mu mol/g/h under visible light irradiation in pure water (about 8.0 times higher than that of PCN), significantly surpassing most previous reports. The design method of manipulating the microstructure of the catalyst combined with the modification of metal nanoparticles provides a new idea for the rational development and application of efficient photocatalysts.
Keyword ：
metal nanoparticle modification metal nanoparticle modification microstructure manipulation microstructure manipulation carbon nitride carbon nitride hydrogen peroxide hydrogen peroxide photocatalyst photocatalyst
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| GB/T 7714 | Hou, Jixiang , Zhang, Xu , Wang, Kaiwen et al. Synthesis of Silver Nanoparticles-Modified Graphitic Carbon Nitride Nanosheets for Highly Efficient Photocatalytic Hydrogen Peroxide Evolution [J]. | MOLECULES , 2022 , 27 (17) . |
| MLA | Hou, Jixiang et al. "Synthesis of Silver Nanoparticles-Modified Graphitic Carbon Nitride Nanosheets for Highly Efficient Photocatalytic Hydrogen Peroxide Evolution" . | MOLECULES 27 . 17 (2022) . |
| APA | Hou, Jixiang , Zhang, Xu , Wang, Kaiwen , Ma, Peijie , Hu, Hanwen , Zhou, Xiyuan et al. Synthesis of Silver Nanoparticles-Modified Graphitic Carbon Nitride Nanosheets for Highly Efficient Photocatalytic Hydrogen Peroxide Evolution . | MOLECULES , 2022 , 27 (17) . |
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Abstract ：
Defect engineering modified graphite carbon nitride (g-C3N4) has been widely used in various photocatalytic systems due to the enhanced catalytic activity of multiple defect sites (such as vacancies or functional groups). However, the key mechanism of action in each defect site in the corresponding photocatalytic surface reactions is still unclear. Here, the -C N groups and N vacancies were sequentially introduced into g-C3N4 (Nv-C N-CN) for photocatalytic production of high-value and multifunctional H2O2, and the effect of dual defect sites on the overall photocatalytic conversion process was systematically analyzed. The modification of the dual defect sites forms an electron-rich structure and leads to a more localized charge density distribution, which not only enhances the light absorption and carrier separation capabilities, but also significantly improves the selectivity and activity of H2O2 generation. Importantly, detailed experimental characterizations and theoretical calculations clearly revealed the key role of each defect site in the photocataLytic H2O2 surface reaction mechanism: the N vacancies can effectively adsorb and activate O-2, and the -C N groups facilitate the adsorption of H+, which synergistically promote H2O2 generation. The Nv-C N-CN reached a H2O2 generation rate of 3093 mu moL g(-1)h(-1) and achieved an apparent quantum efficiency of 36.2% at 400 nm, significantly surpassing the previously reported g-C3N4-based photocatalysts. Meanwhile, a solar-to-chemical conversion efficiency of 0.23% was achieved in pure water. Constructing defects and understanding their crucial role provides significant insights into the rational use of defect engineering to design and synthesize highly active catalytic materials for energy conversion and environmental remediation.
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| GB/T 7714 | Zhang, Xu , Ma, Peijie , Wang, Cong et al. Unraveling the dual defect sites in graphite carbon nitride for ultra-high photocatalytic H2O2 evolution [J]. | ENERGY & ENVIRONMENTAL SCIENCE , 2022 , 15 (2) : 830-842 . |
| MLA | Zhang, Xu et al. "Unraveling the dual defect sites in graphite carbon nitride for ultra-high photocatalytic H2O2 evolution" . | ENERGY & ENVIRONMENTAL SCIENCE 15 . 2 (2022) : 830-842 . |
| APA | Zhang, Xu , Ma, Peijie , Wang, Cong , Gan, Liyong , Chen, Xianjie , Zhang, Peng et al. Unraveling the dual defect sites in graphite carbon nitride for ultra-high photocatalytic H2O2 evolution . | ENERGY & ENVIRONMENTAL SCIENCE , 2022 , 15 (2) , 830-842 . |
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Abstract ：
Programmable magnetic field-free manipulation of perpendicular magnetization switching is essential for the development of ultralow-power spintronic devices. However, the magnetization in a centrosymmetric single-layer ferromagnetic film cannot be switched directly by passing an electrical current in itself. Here, we demonstrate a repeatable bulk spin-orbit torque (SOT) switching of the perpendicularly magnetized CoPt alloy single-layer films by introducing a composition gradient in the thickness direction to break the inversion symmetry. Experimental results reveal that the bulk SOT-induced effective field on the domain walls leads to the domain walls motion and magnetization switching. Moreover, magnetic field-free perpendicular magnetization switching caused by SOT and its switching polarity (clockwise or counterclockwise) can be reversibly controlled in the IrMn/Co/Ru/CoPt heterojunctions based on the exchange bias and interlayer exchange coupling. This unique composition gradient approach accompanied with electrically controllable SOT magnetization switching provides a promising strategy to access energy-efficient control of memory and logic devices.
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| GB/T 7714 | Xie Xuejie , Zhao Xiaonan , Dong Yanan et al. Controllable field-free switching of perpendicular magnetization through bulk spin-orbit torque in symmetry-broken ferromagnetic films. [J]. | Nature communications , 2021 , 12 (1) : 2473 . |
| MLA | Xie Xuejie et al. "Controllable field-free switching of perpendicular magnetization through bulk spin-orbit torque in symmetry-broken ferromagnetic films." . | Nature communications 12 . 1 (2021) : 2473 . |
| APA | Xie Xuejie , Zhao Xiaonan , Dong Yanan , Qu Xianlin , Zheng Kun , Han Xiaodong et al. Controllable field-free switching of perpendicular magnetization through bulk spin-orbit torque in symmetry-broken ferromagnetic films. . | Nature communications , 2021 , 12 (1) , 2473 . |
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Abstract ：
Silicon heterojunction solar cells are expected to increase their market share in the near future. Qu et al. identify an embedded nanotwin structure at the crystalline silicon/hydrogenated amorphous silicon interface of silicon heterojunction cells that limits the device performance and devise an approach to suppress its formation. The interface of high-quality crystalline silicon/hydrogenated amorphous silicon (c-Si/a-Si:H) is indispensable for achieving the ideal conversion efficiency of Si heterojunction solar cells. Therefore, it is extremely desirable to characterize and control the interface at the atomic scale. Here, we employ spherical aberration-corrected transmission electron microscopy to investigate the atomic structure of the c-Si/a-Si:H interface in high-efficiency Si heterojunction solar cells. Their structural evolution during in situ annealing is visualized at the atomic scale. High-density embedded nanotwins, detrimental to the device performance, are identified in the thin epitaxial layer between c-Si and a-Si:H. The nucleation and formation of these nanotwins are revealed via ex situ and in situ high-resolution transmission electron microscopy. Si heterojunction solar cells with low-density nanotwins are fabricated by introducing an ultra-thin intrinsic a-Si:H buffer layer and show better performance, indicating that the strategy to restrain embedded nanotwins can further enhance the conversion efficiency of Si heterojunction solar cells.
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| GB/T 7714 | Qu, Xianlin , He, Yongcai , Qu, Minghao et al. Identification of embedded nanotwins at c-Si/a-Si:H interface limiting the performance of high-efficiency silicon heterojunction solar cells [J]. | NATURE ENERGY , 2021 , 6 (2) : 194-202 . |
| MLA | Qu, Xianlin et al. "Identification of embedded nanotwins at c-Si/a-Si:H interface limiting the performance of high-efficiency silicon heterojunction solar cells" . | NATURE ENERGY 6 . 2 (2021) : 194-202 . |
| APA | Qu, Xianlin , He, Yongcai , Qu, Minghao , Ruan, Tianyu , Chu, Feihong , Zheng, Zilong et al. Identification of embedded nanotwins at c-Si/a-Si:H interface limiting the performance of high-efficiency silicon heterojunction solar cells . | NATURE ENERGY , 2021 , 6 (2) , 194-202 . |
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Abstract ：
Discovering high-performance near-room-temperature thermoelectric materials is extremely imperative to widen the practical application in thermoelectric power generation and refrigeration. Here, ternary Ag2Se1-xTex (x = 0.1, 0.2, 0.3, 0.4, and 0.5) materials are prepared via the wet-mechanical alloying and spark plasma sintering process to investigate their near-room-temperature thermoelectric properties. From density functional theory calculation and single-parabolic-band modeling study, we found that the reduced contribution of Se 4p orbitals to the total density of states decreases the carrier effective mass with increasing Te content, which should enhance the theoretically maximum zT. These calculation results are also verified by the experimental results. Meanwhile, complex microstructures including dislocations, nanograins, high-density boundaries, Te-Se substitution, lattice distortions, and localized strain have been observed in ternary Ag2Se1-xTex. These complex microstructures strengthen phonon scattering and in turn lead to ultralow lattice thermal conductivity in the range of 0.21-0.31 W m(-1) K-1 in ternary Ag2Se1-xTex at 300 K. Although the increased deformation potential suppresses the carrier mobility, benefiting from the engineered band structures and ultralow lattice thermal conductivity, a high zT of >1 can be potentially obtained in the ternary Ag2Se1-xTex with appropriate carrier concentration. This study indicates that ternary Ag2Se1-xTex is a promising candidate for near-room-temperature thermoelectric applications.
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| GB/T 7714 | Chen, Jie , Yuan, Hualei , Zhu, Yu-Ke et al. Ternary Ag2Se1-xTex: A Near-Room-Temperature Thermoelectric Material with a Potentially High Figure of Merit [J]. | INORGANIC CHEMISTRY , 2021 , 60 (18) : 14165-14173 . |
| MLA | Chen, Jie et al. "Ternary Ag2Se1-xTex: A Near-Room-Temperature Thermoelectric Material with a Potentially High Figure of Merit" . | INORGANIC CHEMISTRY 60 . 18 (2021) : 14165-14173 . |
| APA | Chen, Jie , Yuan, Hualei , Zhu, Yu-Ke , Zheng, Kun , Ge, Zhen-Hua , Tang, Jun et al. Ternary Ag2Se1-xTex: A Near-Room-Temperature Thermoelectric Material with a Potentially High Figure of Merit . | INORGANIC CHEMISTRY , 2021 , 60 (18) , 14165-14173 . |
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