Direct Growth of Edge-Rich Graphene with Tunable Dielectric Properties in Porous Si3N4 Ceramic for Broadband High-Performance Microwave Absorption
Direct Growth of Edge-Rich Graphene with Tunable Dielectric Properties in Porous Si3N4 Ceramic for Broadband High-Performance Microwave Absorption
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在多孔 Si3N4 陶瓷中直接生长具有可调介电性能的富边缘石墨烯，用于宽带高性能微波吸收
DOI：
10.1002/adfm.201707205
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发表时间：
2018
影响因子：
19
通讯作者：
Li Hejun
中科院分区：
文献类型：
--
作者：
Ye Fang;Song;Qiang;Zhang Zhenchuang;Li Wei;Zhang Shouyang;Yin Xiaowei;Zhou Yuzhao;Tao Huiwen;Liu Yongsheng;Cheng Laifei;Zhang Litong;Li Hejun
高性能的石墨烯微波吸收材料在日常生活和一些极端情况下是非常理想的。直接生长石墨烯作为透波基质中的吸收填充物的简单技术对于将其应用于现实世界至关重要。本文报道了一种简单的化学气相沉积(CVD)法直接在多孔Si3N4陶瓷中生长具有定制结构和可调介电性能的富边石墨烯(ERG)的方法。CH3OH的大O/C原子比有助于建立温和的氧化气氛，并导致具有开放的石墨纳米台阶和独立的纳米平面的独特结构，使ERG/Si3N4杂化材料在良好的阻抗匹配和强大的损耗能力之间获得适当的平衡。相应地，所制备的材料具有良好的电磁波吸收性能，远远超过传统的CVD石墨烯和还原石墨烯氧化物材料，获得了覆盖整个X波段的4.2 GHz的有效吸收带宽，厚度为3.75 mm，吸收剂的负载量可以忽略不计。研究结果为开发具有强反射损耗和宽吸收频率范围的新型微波吸收材料提供了新的思路。
High‐performance graphene microwave absorption materials are highly desirable in daily life and some extreme situations. A simple technique for the direct growth of graphene as absorption fillers in wave‐transmitting matrices is of paramount importance to bring it to real‐world application. Herein, a simple chemical vapor deposition (CVD) route for the direct growth of edge‐rich graphene (ERG) with tailored structures and tunable dielectric properties in porous Si3N4ceramics using only methyl alcohol (CH3OH) as precursor is reported. The large O/C atomic ratio of CH3OH helps to build a mild oxidizing atmosphere and leads to a unique structure featuring open graphite nanosteps and freestanding nanoplanes, endowing the ERG/Si3N4hybrid with an appropriate balance between good impedance matching and strong loss capacity. Accordingly, the prepared materials exhibit superior electromagnetic wave absorption, far surpassing that of traditional CVD graphene and reduced graphene oxide‐based materials, achieving an effective absorption bandwidth of 4.2 GHz covering the entire X band, with a thickness of 3.75 mm and a negligibly low loading content of absorbents. The results provide new insights for developing novel microwave absorption materials with strong reflection loss and wide absorption frequency range.