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S‐Scheme 2D/2D Bi_(2)MoO_(6)/BiOI van der Waals heterojunction for CO_(2) photoreduction

Chinese Journal of Catalysis 2022年第7期43卷 1657-1666页

作者： Zhongliao Wang Bei Cheng Liuyang Zhang Jiaguo Yu Youji Li S.Wageh Ahmed A.Al‐Ghamdi State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070HubeiChina Laboratory of Solar Fuel Faculty of Materials Science and ChemistryChina University of GeosciencesWuhan 430074HubeiChina College of chemistry and chemical engineering Jishou UniversityJishou 416000HunanChina Department of Physics Faculty of ScienceKing Abdulaziz UniversityJeddah 21589Saudi Arabia

Reducing CO_(2) to hydrocarbon fuels by solar irradiation provides a feasible channel for mitigating excessive CO_(2) emissions and addressing resource ***,severe charge recombi‐nation and the high energy barrier for CO_(2) photoreduction on the surface of photocatalysts com‐promise the catalytic ***,a 2D/2D Bi_(2)MoO_(6)/BiOI composite was fabricated to achieve improved CO_(2) photoreduction *** transfer in the composite was facilitated by the van der Waals heterojunction with a large‐area *** function calculation demon‐strated that S‐scheme charge transfer is operative in the composite,and effective charge separation and strong redox capability were revealed by time‐resolved photoluminescence and electron para‐magnetic resonance ***,the intermediates of CO_(2) photoreduction were identi‐fied based on the in situ diffuse reflectance infrared Fourier‐transform *** functional theory calculations showed that CO_(2) hydrogenation is the rate‐determining step for yielding CH_(4) and *** Bi_(2)MoO_(6) into the composite further decreased the energy barrier for CO_(2) photoreduction on BiOI by 0.35 *** study verifies the synergistic effect of the S‐scheme heterojunction and van der Waals heterojunction in the 2D/2D composite.

关键词： 2D/2D S‐scheme heterojunction van der Waals heterojunction CO_(2)photoreduction

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Molecular Dynamics Simulation and Test Characterization of Metal Migration Behavior in Antimony-Impregnated Graphite

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SSRN 2024年

作者： Lu, Junjie Ma, Yurun Shi, Junqin Li, He Zhang, Wei NingboTech University Ningbo Key Laboratory of Advanced Seal Ningbo China State Key Laboratory of Solidification Processing Center of Advanced Lubrication and Seal Materials Northwestern Polytechnic University Shaanxi Xi'An710072 China Key Laboratory of Marine Materials and Related Technologies Zhejiang Key Laboratory of Marine Materials and Protective Technologies Ningbo Institute of Materials Technology and Engineering Chinese Academy of Sciences Ningbo China Northwest Institute for Non-ferrous Metal Research

The research commenced with the synthesis of antimony-impregnated graphite composites, designated as C/Sb20%. The samples were characterized by friction test and surface test. Furthermore, the simulation of analytical dynamics is carried out. Notably, findings from the simulations reveal a dramatic decline in antimony concentration within the C/Sb20% samples. Concurrently, the emergence of Sb2O3 and Sb2O5 oxides was observed, indicating oxidative phenomena. Further elucidation from FIB-TEM analysis confirmed that the antimony lattice within the C/Sb20% consistently exhibited a face-centered cubic configuration. This study unveils the extraordinary activity and "softening" of antimony flake structures. This transformation, from flake to agglomerated forms, coupled with sliding friction, leads to the disruption of the graphite's internal structure, facilitating the continuous efflux of antimony. © 2024, The Authors. All rights reserved.

关键词： Molecular dynamics

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Microstrip Antenna Arrays Based on Two-dimensional Titanium Carbide (MXene) Films

Microstrip Antenna Arrays Based on Two-dimensional Titanium ...

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International Conference on Microwave and Millimeter Wave technology Proceedings

作者： Jiannan Guo Hao-Ran Zu Runjie Yang Xueyu Liu Bao-Wen Li Rongguo Song Daping He Hubei Engineering Research Center of RF-Microwave Technology and Application Wuhan China State Key Laboratory of Advanced Technology for Materials Synthesisand Processing Center of Smart Materials and Devices Wuhan China

In this work, a microstrip antenna array based on a two-dimensional titanium carbide (MXene) film with an operating frequency of 3.5 GHz is proposed for the first time. MXene film has a conductivity of 5*10 5 S/m and a thickness of 15 μm, which has good ductility and flexibility. The radiating units are arranged by 2 units, and the microstrip lines with parallel feeding between the array elements directly feed the antenna. The return loss of the proposed 2*2 MXene antenna array is -24.3 dB, and the impedance bandwidth of a -10 dB is 11.1% (3.21 GHz-3.66 GHz), and a maximum gain of 5.73 dBi. The results show that the MXene antenna array has excellent performance and verifies the feasibility of preparing high-performance antennas, which have significant potential for future 5G mobile communication. It has crucial application potential in future 5G mobile communication.

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Nonmetallic Trace Elements X (X = H, C, N, O, B and S) Induced Rhenium Co-Segregation in Nickel Σ5 (210) Symmetrical Tilt Grain Boundary

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SSRN 2023年

作者： Xue, Hongtao Dang, Ruidong Tang, Fuling Lu, Xuefeng Ren, Junqiang Li, Junchen State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals School of Materials Science and Engineering Lanzhou University of Technology Lanzhou730050 China

The thermally/mechanically-driven structural instability of nano- and coarse-grained polycrystalline metals originates from the unstable grain boundaries (GBs). GB segregation of solute elements could not only stabilize but also embrittle GBs. To improve GB stability and cohesion in parallel via solute segregations, in this work the segregation behavior of six non-metallic impurities X at the Σ5 [001](210) GB of nickel-based alloys, their co-segregations with Re element that has no GB segregation tendency, and segregation-induced changes in GB properties were investigated comprehensively from first-principles calculations. We discovered that these nonmetallic elements can segregate to the Ni GB and thus stabilize it, but they are GB embrittlers except B. Annealing temperature and bulk concentration have no effect on the S segregation. With the X pre-segregations, induced GB segregations of Re were observed, which lowers the excess energy and enhances the cohesive strength of all X-segregated GBs. The attractive interactions between C/N/B and Re atoms promote the Re segregation. The stabilizing and strengthening mechanisms of Re segregation were mainly attributed to the changes in Fermi level location and the increased interplanar bonding, respectively. Our findings may gain more insights into the atomic-scale GB co-segregations and stabilization of nano- and coarse-grained Ni-based alloys. © 2023, The Authors. All rights reserved.

关键词： Grain boundaries

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Tea stain-inspired solar energy harvesting polyphenolic nanocoatings with tunable absorption spectra

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Nano Research 2021年第4期14卷 969-975页

作者： Lu Yang Yuan Zou Wei Xia Haotian Li Xinyu He Yi Zhou Xianhu Liu Chaoqun Zhang Yiwen Li College of Polymer Science and Engineering State Key Laboratory of Polymer Materials EngineeringSichuan UniversityChengdu 610065China National Engineering Research Center for Advanced Polymer Processing Technology Zhengzhou UniversityZhengzhou 450002China Key Laboratory for Biobased Materials and Energy of Ministry of Education College of Materials and EnergySouth China Agricultural University483 Wushan RoadGuangzhou 510642China Guangdong Laboratory for Lingnan Modem Agricultural Science and Technology 483 Wushan RoadGuangzhou 510642China

Discovery and development of new sustainable photothermal materials with tunable light absorption spectra play a key role in solar energy harvesting and *** possible solution to this quest is to check nature as a source of matters or *** by the formation of tea stains,a unique class of dark stain materials generated by the interfacial reaction between tea polyphenols and metal substance,we reported the facile preparation and screening of a series of photothermal nanocoating layers via the metal ion(i.e.C u(ll)>Fe(lll),Ni(ll),Zn(ll))promoted in situ polymerization of typical phenolic moieties of tea polyphenols(i.e.,catechol and pyrogallol).It was found that those resulting metal-polyphenolic nanocoatings showed various promising features,such as high blackness and strong adhesion,excellent and tunable light absorption properties,good hydrophilicity and long-term *** further fabricated the photothermal composite devices by/n s/'fty formation of meta卜polyphenolic nanocoatings on pristine silks for solar desalination,which demonstrated promising durable evaporation behaviors with excellent evaporation rates and steam generation *** believe that this work could provide more opportunities towards new types of bio-inspired and sustainable photothermal nanomaterials for solar energy harvesting applications such as water desalination.

关键词： metal-polyphenolic nanocoating polymerization light absorption photothermal solar desalination

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First-Principles Study of Discharge Products and Their Stability of Lithium-Nitrogen Batteries

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SSRN 2023年

作者： Qu, Guo-Xiong Zhao, Xu-Dong Wei, Cheng-Dong Zhang, Hong-Yi Yang, Yu-Tong Xue, Hong-Tao Tang, Fu-Ling State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals School of Materials Science and Engineering Lanzhou University of Technology Lanzhou730050 China

In this paper we adopted the first-principles approach to simulate and analyze the possible material changes in the discharge process of Li-N2 battery. The discharge process is simulated on a 4N-graphene anode substrate model, by analyzing its molecular configuration, electrostatic potential, density of states, HOMO, and LUMO. Experimental results confirmed that Li3N is the final stabilization product of Li-N2 battery. Furthermore, we found that the adsorption energy is proportional to the amount of charge transferred. The battery voltage-capacity is computed based on the change of Gibbs free energy curve. The electrical properties of the adsorption system indicate that the adsorption of Li-N2 transforms graphene from a semiconducting material to a metallic one. In addition, the differential charge also indicates that the Li-N substance has a strong adsorption interaction with the substrate, which can play the dual roles of electricity storage and nitrogen fixation. © 2023, The Authors. All rights reserved.

关键词： Electronic properties

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Effect of Al(Oh)3 on the Properties of Silicon-Based Ceramic Cores Prepared by Laser Powder Bed Fusion Combined with Vacuum Infiltration

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SSRN 2024年

作者： Liu, Heng Zhang, Ren-Zhong Wu, Jia-Min Li, Wei-Kang Zhou, Shi-Xiang Zhang, Jie Zheng, Wen Yan, Chun-Ze Wen, Shi-Feng Ye, Chun-Sheng Shi, Yu-Sheng Chen, Chao-Yue Ren, Zhong-Ming State Key Laboratory of Materials Processing and Die & Mould Technology School of Materials Science and Engineering Huazhong University of Science and Technology Wuhan430074 China Engineering Research Center of Ceramic Materials for Additive Manufacturing Ministry of Education Wuhan430074 China Wenzhou Key Laboratory of Microwave Communication Materials and Devices Wenzhou Advanced Manufacturing Institute of HUST Wenzhou325035 China State Key Laboratory of Advanced Special Steels School of Materials Science and Engineering Shanghai University Shanghai200444 China

Silicon-based ceramic cores with low coefficients of thermal expansion, low sintering temperatures, and excellent acid and alkali leaching capabilities are indispensable materials in the production of hollow blades. However, the mechanical properties of these materials are not ideal, and there are many challenges in processing them. In this study, silicon-based ceramic cores were prepared using a combination of vacuum infiltration (VI) and laser powder bed fusion (LPBF) techniques. Al(OH)3 was employed as a mineralizer to enhance post-sintering mechanical properties and improve the efficiency of vacuum infiltration, thereby enhancing the overall performance of the silicon-based ceramic cores. The VI process enabled nano-SiO2 to penetrate the sample, increasing its density and promoting cristobalite formation during sintering at 1225°C. Furthermore, Al(OH)3 powder enhanced ambient temperature flexural strength by reducing microcracks, inhibiting excessive cristobalite transformation, and improving the VI process. By optimizing the Al(OH)3 content and refining the VI procedure, significant improvements in the microstructure and properties of silicon-based ceramic cores were achieved. Following three rounds of vacuum infiltration and the incorporation of 4 wt.% Al(OH)3, the samples demonstrated a high-temperature creep of 0.17 mm, with flexural strengths of 15.23 MPa at room temperature and 23.55 MPa at high temperature. © 2024, The Authors. All rights reserved.

关键词： Bending strength

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Boosting Effective Capacitance of Nano-Grained Batio3-Based Ceramics Via a Precise Core-Shell Structure Optimization Strategy

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SSRN 2024年

作者： Zhu, Chaoqiong Cai, Ziming Xiao, Mengjian Jiang, Ying Feng, Peizhong Li, Shiheng Cao, Xiuhua Fu, Zhenxiao Wang, Xiaohui School of Materials Science and Physics China University of Mining and Technology Jiangsu Xuzhou221116 China State Key Laboratory of New Ceramics and Fine Processing School of Materials Science and Engineering Tsinghua University Beijing100084 China State Key Laboratory of Advanced Materials and Electronic Components Guangdong Fenghua Advanced Technology Holding Co. Ltd. Guangdong Province Zhaoqing526000 China

Under the trend of miniaturization of multilayer ceramic capacitors (MLCCs), thinner dielectric layers withstood a higher electric field will suffer larger deterioration in capacitance. Thus, it is urgent to improve the DC-bias stability and maintain a considerable effective capacitance under high electric fields to match the requirements of high-end MLCCs. In this work, a strategy of regulating the DC-bias performance via the core-shell structure modulation is proposed. Both numercial predictions and experimental verifications show that the DC-bias performance of core-shell structured ceramic samples can be significantly optimized under the double action of shell thickening and shell dielectric constant increasing, achieving considerable dielectric constant and DC-bias stability simultaneously. The Dy-Mg-co-doping BT-based ceramics with an average grain size about 180nm successfully achieved an outstanding DC-bias performance, realizing a high dielectric constant about 2000 together with a low DC-bias attenuation coefficient of -23.6%@4 kV/mm and guaranteeing a high effective capacitance especially in high fields. © 2024, The Authors. All rights reserved.

关键词： Finite element method

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Unravel the Anchoring Effect and Charge Changes of Li2sn on 2d-Tmd2 for Li-S Batteries: A Dft Study

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SSRN 2023年

作者： Zhao, Fenning Yang, Yutong Xue, Hongtao Tang, Fuling State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals School of Materials Science and Engineering Lanzhou University of Technology Lanzhou730050 China

Two-dimensional transition metal disulfides (2D-TMDs) with a large specific surface area and stable layer structure, have been produced as catalysis, photonics, or other discipline materials. In this work, we investigated their strong polysulfide compatibility and new possible usage as Li-S batteries cathode materials. We explored the anchoring effect and charge changes of polysulfides (Li2Sn, n = 1, 2, 4, 6, 8, including S8) on 2D-TMDs (TM are Fe, Co, Cu, Zn, Ni, Pt, and Pd) matrix materials using first-principles calculations. The electrostatic potentials of 2D-TMDs indicated that they possess a plate structure with a positively charged core and negatively charged outer sides, which facilitates the adsorption of positively charged Li+. It was found that 2D-FeS2 is a special one, and it adsorbs Li2S stronger than other 2D-TMD2, with an adsorption energy of -4.28 eV and charge changes of 1.32 e. We also confirmed a significant linear relationship between the power of charge changes (Q) and the adsorption energy: E = 0.43 + 1.76 Q2.8 for 2D-FeS2 and E = 0.08 + 2.74 Q1.5 for other 2D-TMD2, respectively. And the correlation coefficient is larger than 0.90. These seven materials are expected to be viable cathode materials, providing a theoretical foundation for the usage of 2D-TMDs in Li-S batteries. © 2023, The Authors. All rights reserved.

关键词： Sulfur compounds

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Hydrogen Trapping and Embrittlement Behavior in a Second-Generation Ni-Based Single Crystal Superalloy

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SSRN 2024年

作者： Lu, Guangxian Zhao, Yunsong Zhao, Tingting Chen, Yanhui Wang, William Yi Wen, Zhixun State Key Laboratory of Clean and Efficient Turbomachinery Power Equipment School of Mechanics Civil Engineering and Architecture Northwestern Polytechnical University Xi'An710072 China Science and Technology on Advanced High Temperature Structural Materials Laboratory Beijing Institute of Aeronautical Materials Beijing100095 China State Key Laboratory of Solidification Processing Northwestern Polytechnical University Xi'An710072 China Institute of Microstructure Property of Advanced Materials Beijing University of Technology Beijing100124 China National Key Laboratory of Science and Technology on Advanced High Temperature Structural Material China

The present study explores the hydrogen trapping capability and hydrogen embrittlement (HE) behaviors of a second-generation single crystal (SX) superalloy. The susceptibility of HE improves with the increased hydrogen charging duration. Hydrogen induces more cleavages, micro-cracks and denser slip traces. Hydrogen facilitates the formation of nano-voids and the activation of high-density dislocations, leading to denser slip bands which are initiation sites of micro-cracks. Hydrogen is prone to be solutioned in the γ matrix and reversibly trapped at the γ/γ' interface. The First-principles calculations indicate that hydrogen reduces the binding strength at the γ/γ' interface, which promotes the propagation of micro-cracks. © 2024, The Authors. All rights reserved.

关键词： Hydrogen

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