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Equipment-friendly encapsulation structure of SiO2/Cu for efficient infrared shield

MATERIALS & DESIGN 2022年 214卷

作者： Li, Xiaonan Li, Tianpeng Guo, Aiqiang Su, Wenjia Gao, Xinbao Army Engn Univ Shijiazhuang Campus Shijiazhuang 050003 Hebei Peoples R China

SiO2/Cu equipment-friendly infrared interfering agent was built from tetraethoxysilane and flake copper powder through in-situ synthesis reaction. SEM images indicated the encapsulation structure of the samples. FT-IR, XPS and XRD spectra revealed the presence of SiO2 that was coated into the surface and edge of Cu. The shielding performance and the electrical property could be controlled by adjusting the content of SiO2. The infrared transmittance of SiO2/Cu was 23.29% at 1 3 gm, 22.92% at 3 5 gm and 21.70% at 8 14 gm. The mass extinction coefficient was 1.47 m2g1 at 1 3 gm, 1.48 m2g1 at 3 5 gm and 1.54 m2g1 at 8 14 gm, and the resistivity was 1.20 1010 I cm at 10 MPa. There was no significant difference found between the shielding performance of Cu and SiO2/Cu. Deposition of SiO2 in this structure supplies high resistivity and excellent shielding performance, and provides highly efficient infrared interfering agent without damaging the basic structure of Cu. This work demonstrates that in-situ synthesis method is a facile and efficient strategy to obtaining optimal shielding performance of SiO2/Cu equipment-friendly infrared interfering agent and met the expectations and synthesis methods from our original material design. (c) 2022 Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http:// ***/licenses/by-nc-nd/4.0/).

关键词： Equipment-friendly Precision-guided munition Flake copper powder encapsulation structure Passive interference

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Ultra-High Activity and Durability of Low-Platinum Fuel Cells Enabled by encapsulation of L10-PtCo and L12-Pt3Co Intermetallic Compounds

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SMALL 2025年第1期21卷 e2407163页

作者： Li, Gong Bai, Jingsen Liu, Changpeng Jin, Zhao Xiao, Meiling Xing, Wei Univ Sci & Technol China Sch Appl Chem & Engn Hefei 230026 Peoples R China Chinese Acad Sci Changchun Inst Appl Chem State Key Lab Electroanalyt Chem Jilin Prov Key Lab Low Carbon Chem Power Changchun 130022 Peoples R China CAS HK Joint Lab Hydrogen Energy Changchun 130022 Peoples R China

Developing high-performance, durable, and ultralow-loading platinum (Pt) catalysts for the oxygen reduction reaction (ORR) is crucial for advancing fuel cells. Here, a novel structured alloy catalyst is reported, characterized by Pt-Co intermetallic compounds with a Pt-skin, encapsulated by a covalent organic framework (COF) derived carbon support. This unique structure, combining alloy-induced strain effects and protective encapsulation, leads to exceptional catalytic activity and stability at an ultralow Pt loading of 0.02 mgPt cm-2. To be specific, this catalyst exhibits peak power densities of 1.77 W cm-2 in fuel cell tests. It demonstrates a state-of-the-art mass activity of 2.15 A mgPt-1 (@0.9 V), which is 5.38 times that of commercial Pt/C (0.40 A mgPt-1). More importantly, the fuel cell assembled with this novel catalyst displays exceptional durability, with a voltage degradation of only 9.9 mV after 100,000 cycles at 0.8 A cm-2 and a mass activity retention of 85% (1.83 A mgPt-1), far exceeding the 2025 initial mass activity (MA) target (0.44 A mgPt-1) of DOE by 4.2 times. Notably, the current density at 0.6 V under hydrogen-air conditions shows only a slight decline after more than 230 h.

关键词： covalent organic framework encapsulation structure fuel cell ordered intermetallic oxygen reduction reaction

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Enhanced Anti-Migration of Organic Antioxidants via Chitosan-Encapsulated Ultrathin Intercalated Layered Double Hydroxides Fabricated by a Nucleation-encapsulation Coupling Strategy

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SMALL 2025年第21期21卷 e2503473页

作者： Li, Zijia Zhao, Menghua Guan, Jun Taviot-Gueho, Christine Leroux, Fabrice Feng, Yongjun Beijing Univ Chem Technol State Key Lab Chem Resource Engn Beijing 100029 Peoples R China Univ Clermont Auvergne CNRS Inst Chim Clermont Ferrand ICCF UMR 6296 F-63171 Aubiere France

Antioxidants play a crucial role in inhibiting polypropylene (PP) oxidative damage and extending polymer lifetime. However, the high migration rate and limited efficiency reduced protection, often requiring overdosing, which raises environmental and health issues. Herein, a more sustainable solution involves an ultrathin antioxidant intercalated layered double hydroxides (LDHs) with chitosan (CS) encapsulation to block the antioxidants migration by tuning CS molecular weight to fully encapsulate LDH unit. The optimized encapsulation inhibits the antioxidants migration without hindering the interlayer diffusion of radicals, thereby providing better protection for PP. The 200kCS-3L-LDH/PP with the low molecular weight phenolic antioxidant (3,5-Di-tert-butyl-4-hydroxyphenylpropionic acid, abbreviated as DBHP) and encapsulated by CS of MW = 200k at an encapsulation level of 11.6% (actual encapsulation percentage by weight), demonstrates a low migration ratio of 8.17% after 204 h in ethanol at 60 degrees C and overlong thermal aging resistance time (1920 min) under air, surpassing the conventional and most resistant product currently on the market 1010/PP (46.0% and 640 min, respectively). Such "Russian doll" structure offers a promising way to enhance PP with excellent anti-migration and antioxidative performance, while providing a valuable strategy for the design and the controlled release if desired of interlayer species in LDHs.

关键词： anti-migration antioxidant chitosan encapsulation structure layered double hydroxide polypropylene ultrathin

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A sol-gel strategy of constructing nanosized Hf6Ta2O17 encapsulated graphite flakes and its enhancement on the ablation property of carbon/carbon composites

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材料科学技术（英文版） 2025年第1期204卷 292-301页

作者： Guanghui Feng Ruoxi Zhang Xiyuan Yao Hejun Li State Key Laboratory of Solidification Processing Shaanxi Key Laboratory of Fiber Reinforced Light Composite MaterialsNorthwestern Polytechnical UniversityXi'an 710072China Department of Mechanical Engineering City University of Hong KongHong KongChina State Key Laboratory of Solidification Processing Shaanxi Key Laboratory of Fiber Reinforced Light Composite MaterialsNorthwestern Polytechnical UniversityXi'an 710072China

Herein,nanosized Hf6Ta2O17 encapsulated graphite flakes were firstly constructed using the sol-gel method,then deposited on the surface of carbon/carbon(C/C)composites by plasma spraying technique to prolong their service span in critical *** results affirmed the active influ-ence of graphite flakes on elevating the toughness of the Hf6Ta2O17 ***,after being exposed to the oxyacetylene torch with a peak temperature of about 2000 ℃,the sample achieved near zero ab-lation(0.06 mg/s),meanwhile its porosity and mass ablation rate showed 39.5％and 60.0％reduction when compared to pure Hf6Ta2O17 *** exposure,the external Hf6Ta2O17 served as an oxy-gen barrier for internal graphite flakes,inversely internal graphite flakes provided a"pinning"effect on external Hf6Ta2O17,which accounted for its exceptional ablation *** work offers a new insight into the design of surface modification of C/C composites and other high-temperature structural materials.

关键词： Carbon/carbon composites encapsulation structure High-temperature properties Thermal analysis

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Control interfacial charge transfer behavior by creating surface defects on structure unit of heterojunction to drive carrier separation for enhancing photocatalytic CO2 reduction

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JOURNAL OF COLLOID AND INTERFACE SCIENCE 2025年第PT A期677卷 820-830页

作者： Sun, Wei Zuo, Yan Niu, Yaling Che, Guangbo Liu, Chunbo Dong, Hongjun Jilin Normal Univ Coll Engn Siping 136000 Peoples R China Jiangsu Univ Inst Green Chem & Chem Technol Sch Chem & Chem Engn Zhenjiang 212013 Peoples R China Baicheng Normal Univ Baicheng 137000 Peoples R China

Controlling interfacial charge transfer behavior of heterojunction is an arduous issue to efficiently drive separation of photogenerated carriers for improving the photocatalytic activity. Herein, the interface charge transfer behavior is effectively controlled by fabricating an unparalleled VO-NiWO4/PCN heterojunction that is prepared by encapsulating NiWO4 nanoparticles rich in surface oxygen vacancies (VO-NiWO4) in the mesoporous polymeric carbon nitride (PCN) nanosheets. Experimental and theoretical investigations show that, differing with the traditional p-n junction, the direction of built-in electric field between p-type NiWO4 and n-type PCN is reversed interestingly. The strongly codirectional built-in electric field is also produced between the surface defect region and inside of VO-NiWO4 besides in the space charge region, the dual drive effect of which forcefully propels interface charge transfer through triggering Z-Scheme mechanism, thus significantly improving the separation efficiency of photogenerated carriers. Moreover, the unique mesoporous encapsulation structure of VO-NiWO4/ PCN heterostructure can not only afford the confinement effect to improve the reaction kinetics and specificity in the CO2 reduction to CO, but also significantly reduce mass transfer resistance of molecular diffusion towards the reaction sites. Therefore, the VO-NiWO4/PCN heterostructure demonstrates the preeminent activity, stability and reusability for photocatalytic CO2 reduction to CO reaction. The average evolution rate of CO over the optimal 10 %-VO-NiWO4/PCN O-NiWO 4 /PCN composite reaches around 2.5 and 1.8 times higher than that of individual PCN and VO- O- NiWO4, 4 , respectively. This work contributes a fresh design approach of interface structure in the heterojunction to control charge transfer behaviors and thus improve the photocatalytic performance.

关键词： Heterojunction VO-NiWO4/PCN encapsulation structure Surface oxygen vacancy Photocatalytic CO2 reduction

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Encapsulated Fe₃C boosted electrocatalytic performance for oxygen reduction reaction of N-doped carbon nanotube

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Heliyon 2025年第1期11卷 e40862页

作者： Dong, Jun Jiao, Qiqi Wang, Hao Wang, Hong Ren, Yi-ke School of Aerospace Engineering Xi'an Jiaotong University Xi'an 710049 China Shandong Provincial Hospital Affiliated to Shandong First Medical University 324 Jingwu Road Jinan 250021 China China Rongtong Resources Development Group Co. Ltd. Beijing 100081 China Liaoning Qingyang Chemical Industry Corporation Liaoyang 111000 China

The shortcomings of precious metal based catalysts have limited the development of novel energies. So, developing low-cost and high performance transition metal based catalysts is one of the most feasible way to substitute the precious metal based catalysts. In all of the developed catalysts for oxygen reduction reactions (ORR), the iron-based nitrogen doped carbon nanotube (N-CNT) show great promise. In this paper, N-CNT with Fe₃C encapsulated based catalysts (Fe₃C@N-CNT) were synthesized. The encapsulation structure of Fe₃C@N-CNT was confirmed by HAADF-STEM, XANES, XPS, XRD, SEM and other methods. XANES tests show that the doped nitrogen of Fe₃C changed the length of Fe-C bond and furtherly influenced the electron transfer between encapsulated Fe₃C and outer layer N-CNT. Electrochemical tests showed that the half-wave potential and onset potential ORR of 750 °C calcined Fe₃C@N-CNT were 90 mV higher than that of 20 wt% Pt/C. The additional electric field between Fe₃C and N-CNT modulated the C-N bond of surface N-CNT and enhanced the catalytic performance for ORR. This paper reveal that constructing encapsulated additional electron providing center is an effective way to design high performance catalysts. © 2024 The Authors

关键词： Electrocatalysts encapsulation structure Fe3C N-doped CNT Oxygen reduction reaction

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Fabrication and catalytic performance of meso-ZSM-5 zeolite encapsulated ferric oxide nanoparticles for phenol hydroxylation

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Frontiers of Chemical Science and Engineering 2021年第3期15卷 643-653页

作者： Zhenheng Diao Lushi Cheng Wen Guo Xu Hou Pengfei Zheng Qiuyueming Zhou School of Chemical Engineering Advanced Institute of Materials ScienceChangchun University of TechnologyChangchun 130012China

An encapsulation-structured Fe_(2)O_(3)@mesoZSM-5(Fe@MZ5)was fabricated by confining Fe_(2)O_(3) nanoparticles(ca.4 nm)within the ordered mesopores of hierarchical ZSM-5 zeolite(meso-ZSM-5),with ferric oleate and amphiphilic organosilane as the iron source and meso-porogen,*** comparison,catalysts with Fe_(2)O_(3)(ca.12 nm)encapsulated in intra-crystal holes of meso-ZSM-5 and with MCM-41 or ZSM-5 phase as the shell were also prepared via sequential desilication and recrystallization at different pH values and *** phenol hydroxylation performance of the as-prepared catalysts using H_(2)O_(2) as oxidant was *** the encapsulation-structured catalysts,Fe@MZ5 showed the highest phenol conversion and hydroquinone selectivity,which were enhanced by two times compared to the Fe-oxide impregnated ZSM-5(Fe/Z5).Moreover,the Fe-leaching amount of Fe@MZ5 was only 3% of that for Fe/*** influence of reaction parameters,reusability,and ·OH scavenging ability of the catalysts were also *** on the above results,the structure-performance relationship of these new catalysts was preliminarily described.

关键词： phenol hydroxylation encapsulation structure structure-performance relationship meso-ZSM-5 ferric oxide

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Development of Silicalite-1-Encapsulated Ni Catalyst from Ni Phyllosilicate for Dry Reforming of Methane

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CATALYSIS SURVEYS FROM ASIA 2023年第1期27卷 56-66页

作者： Zhang, Yusheng Takahashi, Ryota Kimura, Kentaro Fujitsuka, Hiroyasu Tago, Teruoki Tokyo Inst Technol Dept Chem Sci & Engn Meguro Ku 9 2-12-1 Ookayama Tokyo 1528552 Japan Kyoto Univ Dept Chem Engn Nishikyo Ku Kyoto 6158510 Japan

CO2 (dry) reforming of methane (DRM) is a significant and useful reaction from the standpoint of effective utilization and conversion of two main greenhouse gases to value-added synthesis gas. To achieve highly efficient and stable DRM reaction, a Silicalite-1-encapsulated ultrafine Ni nanoparticle catalyst (Ni@S-1)by using Ni phyllosilicate (Ni-PS) as precursor was newly developed. This Ni@S-1 catalyst exhibited negligible coke deposition (0.5 wt.%) evaluated at 600 degrees C for 5 h. Additionally, this Ni@S-1 catalyst presented high and stable catalytic performances and maintained the Ni nanoparticles with ultrafine size (< 7 nm) at 850 degrees C for 24 h. Therefore, this Ni@S-1 catalyst showed good suppression of coke formation and high resistance to nickel sintering and thus was promising for DRM reaction.

关键词： Ni phyllosilicate Silicalite-1 Ni@S-1 encapsulation structure DRM

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Encapsulated cementite enhances catalytic performance of carbon nanotubes for oxygen reduction reaction

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FUEL 2024年 367卷

作者： Huang, Taizhong Zhang, Xuanhao Zhou, Xiaoming Zhang, Haizhou Ma, Xiaochun Ding, Zhanyu Yu, Jiemei Univ Jinan Sch Chem & Chem Engn 336 Nanxin Zhuang West Rd Jinan 250022 Peoples R China Shandong First Med Univ Dept Cardiovasc Surg Shandong Prov Hosp 324 Jingwu Rd Jinan 250021 Peoples R China

Nonprecious-metal-based materials show great potential to be highly efficient catalysts for oxygen reduction reaction (ORR). There is still room for improvement in the performances of nonprecious-metal-based catalysts for ORR. In this paper, we investigated the catalytic performances of N-doped carbon nanotubes (CNTs) with encapsulated cementite (Fe3C@CNT) for ORR. The encapsulation structure was confirmed by scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy analyses. The catalytic performances of Fe3C@CNT for ORR were investigated by cyclic voltammetry, linear sweep voltammetry, Tafel analysis, rotating disk electrode, and rotating ring-disk electrode tests. The results showed that both the onset potential and half-wave potential of Fe3C@CNT-catalyzed ORR were 60 mV higher than those of 20 wt% Pt/C catalyst. Fe3C@CNT catalyzed ORR mainly happened through a four-electron pathway. The long-time running stability of the Fe3C@CNT was also superior to that of the 20 wt% Pt/C catalyst. The eutectic layers between the CNTs and cementite enhanced the electron transfer from the inner-layer CNT to the surface-layer N-doped CNT. Calculations revealed that the iron and carbon in the cementite were in positive and negative electronic states, respectively. The encapsulated cementite promoted the formation of equipotential circles on the surface-layer CNT, which greatly enhanced the catalytic performance of the Fe3C@CNT for ORR. N-doped CNTs with encapsulated cementite show great potential to be high-performance catalysts for ORR.

关键词： Oxygen reduction reaction Cementite encapsulation structure Carbon nano -tube Catalytic mechanism

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Amperometric sensing of hydrazine in environmental and biological samples by using CeO2-encapsulated gold nanoparticles on reduced graphene oxide

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MICROCHIMICA ACTA 2019年第1期186卷 1-10页

作者： Huang, Hong Li, Tingyu Sun, Yifan Yu, Linghui Wang, Changding Shen, Rong Ye, Weichun Wang, Degui Li, Yumin Lanzhou Univ State Key Lab Appl Organ Chem Lanzhou 730000 Peoples R China Lanzhou Univ Dept Chem Lanzhou 730000 Peoples R China Lanzhou Univ Sch Basic Med Sci Lanzhou 730000 Peoples R China Lanzhou Univ Key Lab Digest Syst Tumors Lanzhou 730000 Peoples R China

CeO2-encapsulated gold nanoparticles (AuNPs) were anchored to reduced graphene oxide (RGO/Au@CeO2) by an interfacial auto-redox reaction in a solution containing tetrachloroauric acid and Ce(III) on a solid support. The resulting material was placed on a glassy carbon electrode (GCE) and used as an electrochemical hydrazine sensor at trace levels. The electrocatalytic activity of the modified GCE towards hydrazine oxidation was significantly enhanced as compared to only RGO/CeO2, or CeO2-encapsulated AuNPs, or AuNPsloaded on CeO(2)modified with RGO. This enhancement is attributed to the excellent conductivity and large surface area of RGO, and the strong interaction between the reversible Ce4+/Ce3+ and Au+/Au-0 redox systems. The kinetics of the hydrazine oxidation was studied by electrochemical methods. The sensor, best operated at a peak voltage of 0.35V (vs. saturated calomel electrode), had a wide linear range (that extends from 10nM to 3mM), a low detection limit(3.0nM), good selectivity and good stability. It was successfully employed for the monitoring of hydrazine in spiked environmental water samples and to in-vitro tracking of hydrazine in cells with respect to its potential ***2-encapsulated gold nanoparticles anchored on reduced graphene oxide with the strong interaction between the reversible Ce4+/Ce3+ and Au+/Au-0 reductions can be used for sensitive detection of hydrazine with detection limit of 3nM and good selectivity in environmental and biological samples.

关键词： encapsulation structure Solid-solution interfacial autoredox reaction Electrochemical sensor In vitro cell detection

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