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Xun Meng

Bio: Xun Meng is an academic researcher from Harbin Institute of Technology. The author has contributed to research in topics: Microwave & Reflection loss. The author has an hindex of 4, co-authored 4 publications receiving 124 citations.

Papers
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Journal ArticleDOI
01 Jun 2020-Carbon
TL;DR: In this paper, a 3D double-core double-shell structure and ingenious introduction of tunable ZnO could improve the microwave absorption performances of the (Fe3O4/ZnO)@C nanocomposites, which can be considered as promising absorbing materials.

119 citations

Journal ArticleDOI
TL;DR: In this article, the morphology and size of Pt-based bimetallic alloys are known to determine their electrocatalytic performance in reactions relevant to fuel cells, such as oxygen reduction reaction (ORR) and methanol oxidation reaction (MOR).
Abstract: The morphology and size of Pt-based bimetallic alloys are known to determine their electrocatalytic performance in reactions relevant to fuel cells. Here, we report a general approach for preparing Pt-M (M = Fe, Co and Ni) bimetallic nano-branched structure (NBs) by a simple high temperature solution-phase synthesis. As-prepared Pt-M NBs show a polycrystalline structure and are rich in steps and kinks on the surface, which promote them favorable bifunctional catalytic properties in acidic electrolytes, specifically in terms of the oxygen reduction reaction (ORR) and methanol oxidation reaction (MOR). Specially, Pt-Co NBs/C catalyst shows 6.1 and 5.3 times higher in specific activity (SA) and mass activity (MA) for ORR than state-of-the-art commercial Pt/C catalysts, respectively. Moreover, it exhibits a loss of 4.0% in SA and 14.4% in MA after 10,000 cycles of accelerated durability tests (ADTs) compared with the initial activities. In addition, we also confirmed the superior MOR activity of Pt-Co NBs/C catalyst in acidic electrolytes. For Pt-M NBs with other alloying metals, the ORR and MOR activities are both higher than commercial catalysts and are in the sequence of Pt-Co/C > Pt-Fe/C > Pt-Ni/C > commercial Pt/C (or PtRu/C). The improved activities and durability can benefit from the morphological and compositional effects. This synthesis approach may be applied to develop bifunctional catalysts with enhanced ORR and MOR properties for future fuel cells designs.

59 citations

Journal ArticleDOI
TL;DR: In this article, the 3D foam-like Fe3O4@C core-shell nanocomposites with foamlike structure have been successfully prepared, which would greatly promote multiple reflection/scattering of the incident microwave.

53 citations

Journal ArticleDOI
01 Apr 2022-Carbon
TL;DR: In this article , a carbon-coated MnFe 2 O 4 /MnO heterojunction nanocomposites with foam-like macroporous structures for high-performance microwave absorption was synthesized.

50 citations

Journal ArticleDOI
TL;DR: In this paper, the composite nanoparticles (NPs), Fe3O4 covered with ultra-thin carbon layer (Fe3O 4/C), were synthesized by simple high temperature solution-phase and subsequent high-temperature steam carbonization methods.

14 citations


Cited by
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Journal ArticleDOI
TL;DR: In this article, the EM response mechanisms of interfacial effects are dissected in depth, and advanced characterization as well as theoretical techniques are highly focused on, and representative optimization strategies are systematically discussed with an emphasis on component selection and structural design.
Abstract: Electromagnetic (EM) absorbers play an increasingly essential role in electronic information age, even towards coming intelligent life. The remarkable merits of heterointerface engineering and its peculiar EM characteristics inject a fresh and infinite vitality to design high-efficiency and stimuli-responsive EM absorbers. However, there still exist huge challenges in understanding and reinforcing these interface effects from the micro and macro perspectives. Herein, the EM response mechanisms of interfacial effects are dissected in depth, and advanced characterization as well as theoretical techniques is highly focused on. Then, the representative optimization strategies are systematically discussed with an emphasis on component selection and structural design. More importantly, the most cutting-edge smart EM functional devices based on heterointerface engineering are reported as highlights. Finally, current challenges and concrete suggestion are proposed, and future perspectives on this promising field are predicted as well. This article is protected by copyright. All rights reserved.

194 citations

Journal ArticleDOI
TL;DR: In this paper, Fe3O4@C/reduced graphene oxide (rGO) nanocomposites with layered structure were fabricated by a feasible solvothermal method.
Abstract: Reasonable nanostructure design and composition are conducive to the electromagnetic wave (EM) absorption behavior of absorbers. Herein, Fe3O4@C/reduced graphene oxide (rGO) nanocomposites with layered structure were fabricated by a feasible solvothermal method. By adjusting the amount of graphene oxide (GO), different dielectric characteristics and impedance matching conditions of Fe3O4@C/rGO nanocomposites could be obtained. Moreover, with amorphous carbon as the matching layer, Fe3O4 and rGO provide strong magnetic loss and dielectric loss, respectively. The results exhibit that Fe3O4@C/rGO nanocomposites own salient EM absorption properties under the combined action of various components and three-level layered structure. In addition, the Fe3O4@C/rGO-20 nanocomposites (the addition of GO is 20 mg) are endowed with the best EM absorption performance, which demonstrates a minimum reflection loss (RLmin) value of −59.23 dB at 6.24 GHz with a sample thickness of 3.57 mm and effective absorption bandwidth (EAB) is 6.72 GHz. Moreover, the widest EAB is 8.24 GHz at a thinner thickness of 2.6 mm with the RL value of −25.80 dB at 14 GHz. This work could be a reference for lightweight, broadband, strong absorption composite absorber.

145 citations

Journal ArticleDOI
01 Jun 2020-Carbon
TL;DR: In this paper, a 3D double-core double-shell structure and ingenious introduction of tunable ZnO could improve the microwave absorption performances of the (Fe3O4/ZnO)@C nanocomposites, which can be considered as promising absorbing materials.

119 citations

Journal ArticleDOI
TL;DR: In this paper, the authors summarized the latest research advances on universal strategies to synthesize multi-dimensional noble metal-based catalysts for electrocatalysis applications by structure optimizations, and concluded the classifications of various universal strategies on preparing MNMCs, involving universal hydro/solvothermal strategy, ligand-mediated method, template-assisted route, epitaxial growth, and CO-confinement strategy.

117 citations

Journal ArticleDOI
TL;DR: In this paper, the mesoporous polydopamine (CoMOF@MPDA) composites with a core-shell structure are prepared by the bottom-up monomicelle assembly.
Abstract: Electromagnetic wave absorbents with hierarchically porous and core–shell structures have significantly positive influence on the electromagnetic wave absorption because of the enhanced interfacial polarization. Furthermore, the core–shell structure also introduces components with strong dielectric loss and good resistance to chemical corrosion. Herein, the cobalt–metal–organic frameworks @mesoporous polydopamine (Co–MOF@MPDA) composites with a core–shell structure are prepared by the bottom-up monomicelle assembly. After calcination, the Co@S-doped carbon core and mesoporous N-doped carbon shell (Co@SC@MNC) were obtained. Through adjusting the calcination temperature, the dielectric and magnetic loss can be tuned, resulting in the strong absorption capability for the electromagnetic wave. The minimum reflection loss reaches −72.3 dB, while the effective absorption bandwidth is as broad as 6.0 GHz. The unique structure and the formation of internal cavity between Co@SC and MNC contribute to the interfacial polarization. The enhancement of the dipole polarization loss and conduction loss are ascribed to the S, N-doped hierarchically porous carbon. Importantly, the presence of Co nanoparticles facilitates the magnetic–dielectric synergy to improve the impedance matching due to the introduction of magnetic loss. The novel structural design has potential application in the electromagnetic wave absorption field.

112 citations