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Study on the Structure, Magnetic Properties and Microwave Absorbing Properties of Rare Earth Doped Cobalt Ferrite: The Influence Mechanism of Different Substitution Positions

SSRN

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SSRN 2022年

作者： Jing, Xiaodong Guo, Mohan Li, Ziyu Qin, Ciyu Chen, Zitao Li, Zuoguang Gong, Huayang Ganjiang Innovation Academy Chinese Academy of Sciences Ganzhou341000 China State Key Laboratory of Multiphase Complex Systems Beijing Engineering Research Centre of Process Pollution Control Institute of Process Engineering Chinese Academy of Sciences No.1 2nd North Street ZhongGuanCun Beijing100190 China School of Rare earths University of Science and Technology of China Hefei230026 China University of Chinese Academy of Sciences Beijing100049 China Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes National Laboratory of Mineral Materials School of Materials Beijing100083 China Science and Technology China University of Geosciences Beijing100083 China

In order to better understand the influence mechanism and law of rare earth (RE) doping on the properties of cobalt ferrite (CFO), RE (including La, Ce, Pr, Nd, Sm, Gd, Ho, Er, Yb, Y) doped CFO nanoparticles were synthesized by sol-gel auto combustion method and other methods. The different roles of RE added to CFO in changing cation distribution and further affecting structure, magnetism and microwave absorption properties due to different substitution positions are studied and reported. The crystal structure formation and crystallite size are studied by X-ray diffraction and the results showed that the replacement of Co2+ ions by RE 3+ ions was more likely to lead to larger lattice distortion and smaller grains compared with the replacement of Fe3+ ions by RE3+ ions. Room temperature magnetization measurements show that the saturation magnetization of CFO decreases with the substitution of RE3+ ions, and the change of coercivity is related to the substitution position and type of RE3+ ions. The coercivity increases significantly with the substitution of Co2+ ions by RE3+ , reaching a maximum of 2423 Oe (Co0.8Gd0.2Fe2O4), and decreases with the substitution of Fe3+ ions by RE3+ . The substitution of Fe3+ ions by Ce3+ , Nd3+ , Yb3+ and Er3+ (substitution amount x=0.05) lead to the increase of remanence. Gd3+ , La3+ , Nd3+ and Y3+ doping can improve the microwave absorption performance of CFO, and Co0.9Nd0.1Fe2O4 had the lowest reflection loss of about -23.35 dB at frequency of 11.12 GHz, corresponding to ~99% microwave energy being absorbed. However, the microwave absorbing property is sensitive to the doping amount. Therefore, the synergistic effect of RE doping and structural regulation is needed to improve the microwave absorption performance. © 2022, The Authors. All rights reserved.

关键词： Ions

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Droplet Control Based on Pinning and Substrate Wettability

arXiv

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arXiv 2023年

作者： Theodorakis, Panagiotis E. Amirfazli, Alidad Hu, Bin Che, Zhizhao Institute of Physics Polish Academy of Sciences Al. Lotników 32/46 Warsaw02-668 Poland Department of Mechanical Engineering York University TorontoONM3J 1P3 Canada Flow Capture AS Industriveien 1 Skedsmokorset2020 Norway State Key Laboratory of Engines Tianjin University Tianjin300072 China

Pinning of liquid droplets on solid substrates is ubiquitous and plays an essential role in many applications, especially in various areas, such as microfluidics and biology. Although pinning can often reduce the efficiency of various applications, a deeper understanding of this phenomenon can actually offer possibilities for technological exploitation. Here, by means of molecular dynamics simulation, we identify the conditions that lead to droplet pinning or depinning and discuss the effects of key parameters in detail, such as the height of the physical pinning-barrier and the wettability of the substrates. Moreover, we describe the mechanism of the barrier crossing by the droplet upon depinning, identify the driving force of this process, and, also, elucidate the dynamics of the droplet. Not only does our work provide a detailed description of the pinning and depinning processes, but it also explicitly highlights how both processes can be exploited in nanotechnology applications to control droplet motion. Hence, we anticipate that our study will have significant implications for the nanoscale design of substrates in micro and nano-scale systems and will assist with assessing pinning effects in various applications. © 2023, CC BY.

关键词： Drops

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Highly Efficient Electrocatalytic CO2Reduction to C2+Products on a Poly(ionic liquid)-Based Cu0–CuITandem Catalyst

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Angewandte Chemie 2021年第9期134卷

作者： Dr. Guo-Yi Duan Xiao-Qiang Li Guang-Rong Ding Prof. Dr. Li-Jun Han Prof. Dr. Bao-Hua Xu Prof. Dr. Suo-Jiang Zhang Beijing Key Laboratory of Ionic Liquids Clean Process CAS Key Laboratory of Green Process and Engineering State Key Laboratory of Multiphase Complex Systems Institute of Process Engineering Chinese Academy of Sciences Beijing 100190 China School of Chemical Engineering University of Chinese Academy of Sciences Beijing 100049 China

Electroreduction of CO 2 on a polymer-modified Cu-based catalyst has shown high multi-electron reduction (>2 e − ) selectivity, however, most of the corresponding current densities are still too small to support industrial applications. In this work, we designed a poly(ionic liquid) (PIL)-based Cu 0 –Cu I tandem catalyst for the production of C 2+ products with both high reaction rate and high selectivity. Remarkably, a high C 2+ faradaic efficiency (FE ) of 76.1 % with a high partial current density of 304.2 mA cm −2 is obtained. Mechanistic studies reveal the numbers and highly dispersed Cu 0 -PIL-Cu I interfaces are vital for such reactivity. Specifically, Cu nanoparticles derived Cu 0 -PIL interfaces account for high current density and a moderate C 2+ selectivity, whereas Cu I species derived PIL-Cu I interfaces exhibit high activity for C−C coupling with the local enriched *CO intermediate. Furthermore, the presence of the PIL layer promotes the C 2+ selectivity by lowering the barrier of C−C coupling.

关键词： CO2 conversion Electrochemistry Ionic liquids Polymer modification Tandem catalyst

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Preparation of Superhydrophobic Coating with Anti-Corrosion and Anti-Fouling Properties on the Surface of Low Manganese Steel by Electrodeposition Technology

SSRN

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SSRN 2023年

作者： Zhang, Lunliang Liu, Xiang Yan, Jingmin Li, Zhengchen Huang, Siyu Weng, Yao Li, Jiang Yuan, Chenzong Han, Peiwei Ye, Shufeng Zhang, Xiaomeng School of Rare earths University of Science and Technology of China Hefei230026 China Ganjiang Innovation Academy Chinese Academy of Sciences Ganzhou341119 China State Key Laboratory of Multiphase Complex Systems Institute of Process Engineering Chinese Academy of Sciences PO Box 353 Beijing100190 China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of Sciences Beijing100049 China Innovation Academy for Green Manufacture Chinese Academy of Sciences Beijing100190 China

As a rare earth slow-release agent, the yttrium (Y) element was often used in anti-corrosion coatings at high temperatures. Still, its application in anti-corrosion coatings at room temperature was rarely studied. Therefore, in this study, a stearic acid-yttrium (SA–Y) superhydrophobic coating was prepared in one step on the surface of low manganese steel by electrodeposition technique. Different electroplating voltages were applied to the electrolyte composed of Y(NO3)3·6H2O and stearic acid (SA), and the effect of the voltage on the surface morphology and wettability of the coating were studied. The results show that the optimum water contact angle of SA–Y superhydrophobic coating is about 162.1 ± 1.2 °, and the corrosion current density of the coating (8.68 × 10-10 A/cm2) is four orders of magnitude lower than that of the low-manganese steel sample (1.22 × 10-6 A/cm2), which confirmed that the coating has good corrosion resistance. At the same time, the soil powders cannot adhere to the surface of SA–Y superhydrophobic coating, indicating that the coating also has good anti-fouling properties. And studies have shown that during the corrosion process, a dense protective layer can be formed on the damaged coating surface to prevent further corrosion of the metal, so the coating has good active protection ability. Therefore, the coating prepared in this study has a good application prospect in the field of ship anti-corrosion. © 2023, The Authors. All rights reserved.

关键词： Morphology

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Revealing the Rate-Limiting Electrode of Lithium Batteries at High Rates and Mass Loadings

SSRN

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SSRN 2022年

作者： Chen, Yongxiu key, Julian O’Regan, Kieran Song, Tengfei Han, Yongsheng Kendrick, Emma School of Metallurgy and Materials University of Birmingham Edgbaston BirminghamBT15 2TT United Kingdom The Faraday Institution Quad One Becquerel Avenue Harwell Campus Didcot OX11 0RA United Kingdom State Key Laboratory of Multiphase Complex Systems Institute of Process Engineering Chinese Academy of Sciences Beijing100190 China School of Chemical Engineering University of Chinese Academy of Sciences Beijing100049 China

Lithium-ion batteries with superior capacities and rate performance are needed due to the soaring demands for higher energy and power device requirements. However, the main hurdle on achieving this predominately results from the poor rate performance of electrode, which is related to thermodynamic limitations and slow kinetics. To determine the rate-limiting electrode in NMC622 vs graphite cells, a methodology based upon the galvanic intermittent titration technique, for investigating the diffusion and reaction kinetics from the observed overpotential at each electrode has been developed. Variable current densities have been used to simultaneously extract the thermodynamic and kinetic properties of each electrode with increasing mass loading. Graphite is observed to reach its thermodynamic limits quicker than NMC, due to the flat plateaus and overpotentials observed from the charge transfer kinetics and mass transport. At high rates and high mass loadings, the graphite electrode is responsible for limiting both Li+ diffusion and reaction rates in full cells. Slow diffusion kinetics are caused by the transport of the electrolyte in the porous electrode, which limits the availability of Li+ for reaction at the surface of graphite. This methodology is proposed as a fast single technique for comprehensively parameterizing the rate limitations observed in a full cell configuration. © 2022, The Authors. All rights reserved.

关键词： Charge transfer

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Preparation of Superhydrophobic Coating with Self-Healing and Antifouling Properties on the Surface of Low Manganese Steel by Electrodeposition Technology

SSRN

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SSRN 2022年

作者： Zhang, Lunliang Liu, Xiang Yan, Jingmin Li, ZhengChen Huang, Siyu Weng, Yao Li, Jiang Yuan, Chenzong Han, Peiwei Ye, Shufeng Zhang, Xiaomeng School of Rare earths University of Science and Technology of China Hefei230026 China Ganjiang Innovation Academy Chinese Academy of Sciences Ganzhou341119 China State Key Laboratory of Multiphase Complex Systems Institute of Process Engineering Chinese Academy of Sciences PO Box 353 Beijing100190 China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of Sciences Beijing100049 China Innovation Academy for Green Manufacture Chinese Academy of Sciences Beijing100190 China

As a rare earth slow-release agent, yttrium (Y) element is often used in anti-corrosion coatings at high temperature, but its application in anti-corrosion coatings at room temperature is rarely studied. Therefore, in this study, a stearic acid-yttrium (SA-Y) superhydrophobic coating was prepared in one step on the surface of low manganese steel by electrodeposition technique. Different electroplating voltages were applied to the electrolyte composed of Y(NO3)3·6H2O and stearic acid (SA), and the effect of the voltage on the surface morphology and wettability of the coating was studied. The results show that the optimum contact angle of SA-Y coating is about 162.1±1.2°. The corrosion current density of the prepared SA-Y coating (5.41×10-12A/cm2) is 6 orders of magnitude lower than that of the low-manganese steel sample (5.63×10-6 A/cm2). It is confirmed that the coating has good corrosion resistance, and the coating also has good antifouling properties. And studies have shown that the damaged coating will form a dense protective layer, and the coating has self-healing ability to prevent further corrosion of the metal. Therefore, the coating prepared in this study have good application prospects in marine anti-corrosion. © 2022, The Authors. All rights reserved.

关键词： Morphology

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Corrigendum to “Modified polyether gylcols supported ionic liquids for CO 2 adsorption and chemical fixation” [Mol. Catal. 492 (2020) 111008-111016]

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Molecular Catalysis 2020年 493卷

作者： Ying Liu Yan Song Jianhua Zhou Xiangping Zhang CAS Key Laboratory of Green Process and Engineering State Key Laboratory of Multiphase Complex System Beijing Key Laboratory of Ionic Liquids Clean Process Institute of Process Engineering Chinese Academy of Science Beijing 100190 China School of Chemistry and Pharmaceutical Engineering Qilu University of Technology Jinan 250353 China

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Preparation of Superhydrophobic Coating with Self-Healing and Antifouling Properties on the Surface of Low Manganese Steel by Electrodeposition Technology

SSRN

引用

SSRN 2022年

As a rare earth slow-release agent, yttrium (Y) element was often used in anticorrosion coatings at high temperature, but its application in anti-corrosion coatings at room temperature was rarely studied. Therefore, in this study, a stearic acid-yttrium (SA-Y) superhydrophobic coating was prepared in one step on the surface of low manganese steel by electrodeposition technique. Different electroplating voltages were applied to the electrolyte composed of Y(NO3)3·6H2O and stearic acid (SA), and the effect of the voltage on the surface morphology and wettability of the coating was studied. The results show that the optimum contact angle of SA-Y coating is about 162.1±1.2°. The corrosion current density of the prepared SA-Y coating (5.41×10-12A/cm2) is 6 orders of magnitude lower than that of the low-manganese steel sample (5.63×10-6 A/cm2). It is confirmed that the coating has good corrosion resistance, and the coating also has good antifouling properties. And studies have shown that the damaged coating will form a dense protective layer, and the coating has self-healing ability to prevent further corrosion of the metal. Therefore, the coating prepared in this study have good application prospects in marine anti-corrosion. © 2022, The Authors. All rights reserved.

关键词： Morphology

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Experimental study on pressure and temperature distribution characteristics of subcritical and supercritical water in vertical flow channel

International Journal of Fluid Engineering

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International Journal of Fluid engineering 2024年第4期1卷 56-64页

作者： Hui Jin Huibo Wang Yi Li Petr A.Nikrityuk State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong UniversityShaanxi 710049China Mechanical Engineering Department Eindhoven University of TechnologyEindhovenNetherlands Chemical and Materials Engineering Department University of AlbertaEdmontonAlberta T6G 2R3Canada

To enhance knowledge about efficiency improvement and reactor optimization in supercritical water gasification,an experimental system was designed to study the pressure and temperature distribution of subcritical and supercritical water in a channel,representing a simplified continuous *** pressure drop and temperature distribution along and perpendicular to the forced flow are studied by the measure points inserted inside the test *** results show that the pressure drop in the test section is linearly negatively correlated with the average enthalpy of the inlet and outlet,eventually reaching negative values(-0.177 MPa)at high average enthalpy(2300 kJ kg^(-1)).Temperature and specific enthalpy along the flow direction match theoretical estimates,except near the pseudocritical *** subcritical cases,horizontal temperature differences are positively correlated with enthalpy differences and mass flow rates but remain nearly constant in supercritical ***,with fluid temperature rising from the pseudocritical point,the horizontal temperature difference first increases,then decreases,and reaching a peak of 4.29 K at a fluid temperature of 664 *** of the obtained data reveals that the negative correlation and values of the pressure drop are caused by fluid volume ***,fluid volume expansion,near-wall natural convection,and turbulent forced flow fluctuations contribute to horizontal temperature non-uniformity.

关键词： flow distribution channel

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Single-atom cobalt-incorporating carbon nitride for photocatalytic solar hydrogen conversion: An X-ray spectromicroscopy study

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Journal of Electron Spectroscopy and Related Phenomena 2023年 264卷

作者： Huang, Yu-Cheng Chen, Jie Lu, Ying-Rui Arul, K. Thanigai Ohigashi, Takuji Chen, Jeng-Lung Chen, Chi-Liang Shen, Shaohua Chou, Wu-Ching Pong, Way-Faung Dong, Chung-Li National Synchrotron Radiation Research Center Hsinchu30010 Taiwan School of Chemical Engineering and Technology Xi'an Jiaotong University Xi'an710049 China Research Center for X-ray Science & Department of Physics Tamkang University New Taipei City25137 Taiwan Photon Factory Institute of Materials Structure Science High Energy Accelerator Research Organization Tsukabu Japan UVSOR Synchrotron Facility Institute for Molecular Science Okazaki Japan International Research Center for Renewable Energy State Key laboratory of Multiphase Flow in Power Engineering Xi`an Jiaotong University Shaanxi Xi`an710049 China Department of Electrophysics National Yang Ming Chiao Tung University Hsinchu30010 Taiwan

The use of carbon nitride-based materials and light to drive catalytic water splitting has enormous potential for the production of hydrogen. Revealing the processes of molecular conjugation, nucleation, and crystallization in crystalline carbon nitride is expected to enhance the photocatalytic activity through the creation of isotype heterojunctions and active sites. In this work, the addition of cobalt salts in ionothermal synthesis was found to promote the phase transition of heptazine-based crystalline carbon nitride (CCN) to triazine-based poly (triazine imide) (PTI), resulting in the formation of a single-atom cobalt-doped coordinated isotype CCN/PTI heterojunction. The new hybrid orbital modulates the atomic/electronic structure and the band gap of the CCN/PTI heterojunction, and synergistically increases the absorption of visible light, accelerating the separation and transfer of photoexcited electrons and holes. Synchrotron-based X-ray spectroscopy and microscopy are used to identify the origin of the improved performance of the single-atom cobalt-doped CCN/PTI heterojunction in the photocatalytic hydrogen evolution reaction. This work demonstrates that synchrotron X-ray spectroscopy is a promising tool for designing materials aimed at enhancing photocatalytic activity in solar energy conversion applications. © 2023 Elsevier B.V.

关键词： Carbon nitride

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