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Nd^(3)+:YAG-Al_(2)O_(3) nanocrystalline transparent ceramics with high inflexion concentration quenching of Nd^(3+) prepared by amorphous crystallization

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Journal of Advanced Ceramics 2024年第8期13卷 1242-1253页

作者： Xiujuan Wan Guangfan Tan Liang Cai Jie Fu Jianqiang Li Yingchun Zhang School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China State Key Laboratory of New Ceramics and Fine Processing School of Materials Science and EngineeringTsinghua UniversityBeijing 100080China State Key Lab for Mesoscience and Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China

Rare earth ion-doped Y_(3)Al_(5)O_(12)(YAG)-based transparent ceramics have been used as important laser gain media for a long time,yet the doping concentration of active ions is limited due to concentration quenching,wherein the inflexion concentration quenching of Nd^(3+)is recognized as 1.0 at%.In this work,YAG-Al_(2)O_(3) nanocrystalline transparent ceramics with a concentration of Nd^(3+)(O-5.0 at%)were fabricated via amorphous crystallization,and the crystal structure evolution,morphology,and optical properties were systematically investigated by differential scanning calorimetry(DSC),X-ray powder diffraction(XRD),transmission electron microscopy(TEM),magnetic resonation(MAS),nuclear magnetic resonation(NMR),and fluorescence *** doping of Nd^(3+)can promote the transition of Al[5]and Al[6]to Al[14],indicating improvements in the ability of the amorphous material to form Nd^(3+):Y_(2)O_(3)-Al_(2)O_(3) vitrified beads,and 1.5 at%Nd^(3+):YAG-Al_(2)O_(3) nanocrystalline transparent ceramics can be obtained by crystallization at 1050℃ with a matrix composed of YAG and concomitant δ-Al_(2)O_(3) and θ-Al_(2)O_(3).The nanocrystalline transparent ceramics show an internal transmitance of 89.56%at 1064 nm,and the strongest emission peak corresponds to the energy transfer from 4F_(3/2) to 4l_(11/2) of Nd^(3+)with a fluorescence lifetime of 231μs when pumped by an 808 nm ***,spectral broadening begins to occur,indicating the onset of concentration quenching,when the concentration of Nd^(3+)exceeds 1.5 at%,substantially higher than the 1.0 at% observed in YAG ***-Al_(2)O_(3) nanocrystalline transparent ceramics obtained by amorphous crystalization can be utilized as the matrix to increase the inflexion point of doping concentration quenching of Nd^(3+),and this material may have great potential as a laser gain medium.

关键词： Y_(3)Al_(5)O_(12)(YAG)-Al_(2)O_(3) nanocrystalline transparent ceramics laser gain medium Nd^(3+)

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Elongated Fe–N–C containing trace atomic Co dopants for high power density PEMFCs

Industrial Chemistry & Materials

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Industrial Chemistry & Materials 2024年第4期2卷 634-643页

作者： Jiayao Cui Junyong Min Hao Wang Jianglan Shui Lishan Peng Zhenye Kang Jieyuan Liu Qingjun Chen Shuo Bai Yanrong Liu CAS Key Laboratory of Green Process and Engineering State Key Laboratory of Mesoscience and EngineeringBeijing Key Laboratory of Ionic Liquids Clean ProcessInstitute of Process EngineeringChinese Academy of SciencesBeijing 100190China School of Chemical Engineering University of Chinese Academy of SciencesBeijing 100049China Longzihu New Energy Laboratory Zhengzhou Institute of Emerging Industrial TechnologyHenan UniversityZhengzhou 450000China School of Materials Science and Engineering Beihang UniversityBeijingChina Ganjiang Innovation Academy Chinese Academy of Sciences Ganzhou 341000China State Key Laboratory of Marine Resource Utilization in South China Sea Hainan Provincial Key Lab of Fine ChemistrySchool of Chemical Engineering and TechnologyHainan UniversityHaikou 570228China

Developing single-atom Fe–N_(4)/C catalysts is crucial for the large-scale implementation of proton exchange membrane fuel cells(PEMFCs).While Fe–N_(4)/C catalysts are inherently active in accelerating the slow ORR process,their performance is still inferior to that of Pt/***,a trace Co-doped Fe single-atom catalyst(Fe(tCo)–N–C)containing more active Fe_(2)N_(8) sites has been ***,compared with typical FeN4 sites in an Fe–N–C electrocatalyst,the Fe_(2)N_(8) sites generate a larger Fe–N bond length due to *** elongated Fe–N bond in Fe_(2)N_(8) lowers the d-band center and charge density of iron sites,enhancing the ORR process by facilitating the formation of*OOH and generation and desorption of****(tCo)–N–C manifested excellent acidic and alkaline ORR activity,with a half-wave potential(E_(1/2))of 0.80 V in HClO_(4) solution and 0.89 V in KOH *** importantly,high peak power densities(Pmax)were realized by applying Fe(tCo)–N–C in PEMFCs,with the Pmax reaching 890 mW cm^(-2) in H_(2)–O_(2) and 380 mW cm^(-2) in H_(2)–***,trace Co dopants in the catalyst improved carbon graphitization and provided high ORR catalytic *** research introduces an innovative approach to engineering highly active Fe_(2)N_(8) sites,providing valuable insights for the sustainable progress of PEMFC technology.

关键词： Proton exchange membrane fuel cells Oxygen reduction reaction Platinum-group-metal-free catalysts Single-atom catalysts Bimetallic active sites

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Thermodynamic analysis of C2H4/C2H6 separation based on silver-based containing ionic liquid

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Chemical engineering Science 2025年 315卷

作者： Yang, Peng Liu, Wei Wang, Zongxu Dong, Haifeng Ren, Mengyu Li, Dan Cai, Aizi Jin, Xiao Wang, Junnan Fang, Yanxiong Guangzhou Key Lab Clean Transport Energy Chemistry School of Light Industry & Chemical Engineering Guangdong University of Technology Guangzhou510006 China CAS Key Laboratory of Green Process and Engineering State Key Laboratory of Mesoscience and Engineering Beijing Key Laboratory of Ionic Liquids Clean Process Institute of Process Engineering Chinese Academy of Sciences Beijing100190 China Huizhou Institute of Green Energy and Advanced Materials Guangdong Huizhou516081 China

Low-energy C2H4/C2H6 separation processes based on ionic liquids are a hot topic of research. Among them, silver-based containing ionic liquids (Ag-ILs) exhibit excellent separation performance. The absorption thermodynamic of this system is crucial for the development of new processes. At 313.15 to 333.15 K, the solubility of C2H4 and C2H6 in Ag-ILs was measured. Combined with the fitting of the solubility of the "deactivation model", the Henry's constant (H) and the reaction equilibrium constant (K) were obtained, which accurately described the absorption behavior of C2H4 in Ag-IL, and the relationship between the enthalpy of absorption and the solubility was correlated. Furthermore, combined with quantum chemical computation, the absorption mechanism was revealed that complexation reaction led to higher solubility of C2H4, and the enthalpy of the reaction is the main driving force. This paper provides theoretical support for the industrial research on the C2H4/C2H6 separation by Ag-IL. © 2025

关键词： Enthalpy

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Techno-Economic Analysis of Small-Scale Ammonia Production Via Sorption-Enhanced Gasification of Biomass

SSRN

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SSRN 2024年

作者： Dziva, Godknows Luan, Chuanbao Ding, Guangchao Boré, Abdoulaye Kouakou, Kouame Jean Ives Tembo, Tinashe Ullah, Atta Zaman, Muhammad Li, Songgeng Zeng, Liang Key Laboratory for Green Chemical Technology Ministry of Education School of Chemical Engineering and Technology Tianjin University Tianjin300072 China State Key Laboratory of Mesoscience and Engineering Institute of Process Engineering Chinese Academy of Sciences Beijing100190 China School of Chemical Engineering University of Chinese Academy of Sciences Beijing100049 China Tianjin Key Lab of Biomass/Wastes Utilization School of Environmental Science and Engineering Tianjin University Tianjin300072 China Lehtrar Road P.O. Nilore Islamabad45650 Pakistan

Biomass gasification is a green and efficient pathway for lowering the carbon footprint of ammonia production. Decentralized, small-scale biomass gasification plants ( © 2024, The Authors. All rights reserved.

关键词： Ammonia

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Steering Phase-Separated Droplets to Control Fibrillar Network Evolution of Supramolecular Peptide Hydrogels

SSRN

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SSRN 2022年

作者： Zhou, Peng Xing, Ruirui Li, Qi Li, Junbai Yuan, Chengqian Yan, Xuehai State Key Laboratory of Biochemical Engineering Institute of Process Engineering Chinese Academy of Sciences Beijing100190 China Beijing National Laboratory for Molecular Sciences CAS Key Lab of Colloid Interface and Chemical Thermodynamics Institute of Chemistry Chinese Academy of Sciences Beijing100190 China University of Chinese Academy of Sciences Beijing100049 China Center for Mesoscience Institute of Process Engineering Chinese Academy of Sciences Beijing100190 China

Controlling the non-covalent cross-linking network morphology of supramolecular hydrogels is of primary importance in tuning their mechanical properties for practical biomaterial applications. In this work, we study the fibrillar network evolution that controls the mechanical properties of the hydrogels by modulating the solute-rich metastable droplets formed via liquid liquid phase separation (LLPS). The size and amount of the droplets, the structural evolution of droplets into pre-fibrils, and fibril network development can be finely tuned by varying the thermal history. There is an optimal initial incubation temperature leading to the hydrogel with the optimized mechanical strength and recovery performance. The mechanism of the temperature dependence of mechanical properties is due to the different non-covalent cross linked gel network morphology through distinct self-assembly pathways. The findings elucidate the key role of phase-separated droplets in the evolution of self-assembling networks during gelation and provide a deeper understanding of engineering supramolecular hydrogels with flexibly tunable mechanical properties. © 2022, The Authors. All rights reserved.

关键词： Molecular dynamics

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Coordination tuned ozone catalytic activity of iron oxides

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Applied Surface Science 2025年 708卷

作者： Jian Guan Yuqi Liu Qiuyi Zhu Guojun Ma Jiayu Zhang Zheyong Fan Wei Chen Jiawei Yang Ning Han Yunfa Chen Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of Sciences Beijing 100049 PR China State Key Laboratory of Mesoscience and Engineering Institute of Process Engineering Chinese Academy of Sciences Beijing 100190 PR China College of Physical Science and Technology Bohai University Jinzhou 121013 PR China The Future Lab Tsinghua University Beijing 100084 PR China

At present, near-ground ozone still acts as an air pollutant, posing threats to human’s health. In this study, Fe-based catalysts with different coordination environments and valance states were synthesized and the coordination environments were verified using EXAFS and XRD Rietveld fitting, while in-situ Raman and in-situ DRIFTs were employed to investigate the oxygen intermediates of ozone catalytic reaction. The following activities order for ozone catalytic reaction was obtained: [FeO 6 ] 3+ ≫ [FeO 4 ] 3+ > [FeO 6 ] 2+ ≈ [FeO 4 ] 2+ proven by DFT calculations, and α-Fe 2 O 3 with [FeO 6 ] 3+ coordination structure has a high efficiency of about 80 % after 2 h at a WHSV of 720000 mL g -1 h −1 and ozone concentration of 1000 ppm. The superior catalytic activity could be attributed to the high crystal splitting energy in the octahedral coordination structure, which could offer electrons easily for the catalytic reaction. This study provides valuable insights for the development of Fe-based ozone catalysts as well as for other transition metal oxides.

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Synergistic Catalysts for Lithium-Sulfur Batteries: Ni Single Atom and MoC Nanoclusters Composites

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Angewandte Chemie 2025年

作者： Chongchong Zhao Yanxia Liu Feng Huo Zhenzhen Guo Yurui Lu Bowen Sun Meng Li Hui Xu Min Zhang Hailin Fan Zixu Sun Andreu Cabot Yatao Zhang Henan Key Laboratory of Energy Storage Materials and Processes Zhengzhou Institute of Emerging Industrial Technology Zhengzhou 450000 China School of Chemical Engineering Zhengzhou University Zhengzhou 450000 China Longzihu New Energy Laboratory Zhengzhou 450000 China Beijing Key Laboratory of Solid State Battery and Energy Storage Process CAS Key Laboratory of Green Process and Engineering State Key Laboratory of Mesoscience and Engineering Institute of Process Engineering Chinese Academy of Sciences Beijing 100190 China Key Lab for Special Functional Materials of Ministry of Education School of Nanoscience and Materials Engineering Henan University Kaifeng 475004 China Catalonia Institute for Energy Research – IREC Sant Adrià de Besòs Barcelona 08930 Spain Catalan Institution for Research and Advanced Studies – ICREA Pg. Lluís Companys 23 Barcelona 08010 Spain

The practical application of sulfur (S) cathodes in lithium-sulfur (Li-S) batteries is hindered by the shuttling of soluble lithium polysulfides (LiPSs) and sluggish sulfur redox kinetics. Addressing these challenges requires advanced catalytic host materials capable of trapping LiPSs and accelerating Li-S redox reactions. However, single-site catalysts struggle to effectively mediate the complex multi-step and multi-phase sulfur conversion processes. In this study, we present a novel dual-site catalyst, Ni-MoC-NC, featuring nickel single atoms anchored to nitrogen sites (Ni-N 4 ) within a carbon nitride (NC) matrix and molybdenum carbide (MoC) nanoclusters. Experimental and theoretical analyses reveal that MoC sites efficiently catalyze the reduction of long-chain LiPSs (Li₂S₈ to Li₂S₄), while Ni-N 4 sites drive the reduction of short-chain LiPSs (Li₂S₄ to Li₂S), resulting in a synergistic enhancement of the complete Li-S redox process. When incorporated as a coating on the cathode side of a commercial polypropylene (PP) separator, the Ni-MoC-NC catalyst enhances sulfur utilization, suppresses LiPSs shuttling, and facilitates a uniform Li + -ion distribution, effectively mitigating the uncontrolled growth of lithium dendrites. Thereby, Li-S batteries employing an S/Ni-MoC-NC cathode and a Ni-MoC-NC@PP separator demonstrate outstanding performance, including an initial capacity of 1624 mAh g⁻¹ at 0.2C and 1142 mAh g⁻¹ at 1C, retaining 590 mAh g⁻¹ after 800 cycles. At a sulfur loading of 8.3 mg cm⁻ 2 and an electrolyte/sulfur ratio of 6 µL mg⁻¹, the system achieves an initial areal capacity of 9.57 mAh cm⁻ 2 at 0.1C, showcasing significant promise for practical applications.

关键词： Dual active sites Li-S battery Lithium polysulfide Long-chain LiPSs Ni-MoC-NC catalysts Short-chain LiPSs

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Schiff Base Mediated Dipeptide Assembly toward Nanoarchitectonics

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Angewandte Chemie 2022年第43期134卷

作者： Dr. Yi Jia Prof. Xuehai Yan Prof. Junbai Li Beijing National Laboratory for Molecular Sciences CAS Key Lab of Colloid Interface and Chemical Thermodynamics Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China State Key Laboratory of Biochemical Engineering Institute of Process Engineering Chinese Academy of Sciences Beijing 100190 China Center for Mesoscience Institute of Process Engineering Chinese Academy of Sciences Beijing 100049 China University of Chinese Academy of Sciences Beijing 100049 China

Dynamic covalent chemistry (DCC) is fascinating because of its dual nature. It perfectly combines the reversible nature of noncovalent bonds with the robustness of covalent bonds, effectively enhancing the stability of assemblies and meanwhile giving rise to unprecedented properties. Therefore, integration of DCC with supramolecular chemistry has emerged as a versatile and an extraordinarily useful approach in directing peptide assembly. This Minireview focuses on a recent strategy, which exploits dynamic Schiff base chemistry in combination with supramolecular chemistry, to mediate dipeptide assembly toward nanoarchitectonics. Diversified structures, new emergent properties, and their related applications are highlighted. Lastly, the opportunities and prospects in this exciting field are also introduced.

关键词： Anticancer Therapy Diphenylalanine Dynamic Covalent Chemistry Optical Waveguiding Schiff Bases

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