Heterogeneous Interface Induced the Formation of Hierarchically Hollow Carbon Microcubes against Electromagnetic Pollution. Issue 43 (4th October 2020)

• Record Type: Journal Article
• Authors: Zhao, Honghong; Xu, Xianzhu; Wang, Yahui; Fan, Dingge; Liu, Dawei; Lin, Kaifeng; Xu, Ping; Han, Xijiang; Du, Yunchen
• Is Part Of: Small. Volume 16:Issue 43(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-10-04
• Subjects: electromagnetic pollution -- heterogeneous interface -- hierarchical carbon microcubes -- SiO2 layer -- ZIF‐67 microcubes; Nanotechnology -- Periodicals; Nanoparticles -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1002/smll.202003407
• Languages: English
• ISSNs: 1613-6810

Abstract

Abstract: Carbon materials with multilevel structural features are showing great potentials in electromagnetic (EM) pollution precaution. With ZIF‐67 microcubes as a self‐sacrificing precursor, hierarchical carbon microcubes with micro/mesoporous shells and hollow cavities have been successfully fabricated with the assistance of rigid SiO2 coating layers. It is found that the SiO2 layer can effectively counteract the inward shrinkage of organic frameworks during high‐temperature pyrolysis due to intensive interfacial interaction. The obtained hollow porous carbon microcubes (HPCMCs) exhibit larger Brunauer–Emmett–Teller surface area and pore volume than porous carbon microcubes (PCMCs) directly derived from ZIF‐67 microcubes. The unique microstructure is confirmed to be favorable for conductive loss and interfacial polarization, thus boosting the overall dielectric loss capability of carbon materials. Besides, hollow cavity will also promote multiple reflection of incident EM waves and intensify the dissipation of EM energy. As expected, HPCMCs harvest better microwave absorption performance, including strong reflection loss intensity and broad response bandwidth, than many traditional microporous/mesoporous carbon materials. This study provides a new strategy for the construction of hierarchical carbon materials and may inspire the design of carbon‐based composites with excellent EM functions. Abstract : Hierarchical carbon microcubes with abundant micro/mesopores and hollow cavity are successfully fabricated through the interaction of heterogeneous interfaces. The unique microstructure favors strong dielectric loss capability through interfacial polarization, dipole polarization, multiple reflection, etc., which contributes to the electromagnetic properties and microwave absorption performance of these hierarchical carbon materials greatly.