Wu Hongjing, Zhao Zehao, Wu Guanglei
MOE Key Laboratory of Material Physics and Chemistry Under Extraordinary, Shaanxi Key Laboratory for Condensed Matter Structure and Properties, School of Science, Northwestern Polytechnical University, Xi'an 710072, China.
MOE Key Laboratory of Material Physics and Chemistry Under Extraordinary, Shaanxi Key Laboratory for Condensed Matter Structure and Properties, School of Science, Northwestern Polytechnical University, Xi'an 710072, China.
J Colloid Interface Sci. 2020 Apr 15;566:21-32. doi: 10.1016/j.jcis.2020.01.064. Epub 2020 Jan 20.
Transition metal compositions (Fe, Co and Ni) have always been promising candidates for electromagnetic wave (EMW) absorbers. In this study, the FeCo layered double hydroxide (LDH) supported on raspberry-like carbon spheres (RCs) was synthesized by a simple hydrothermal method and the spontaneous electrostatic self-assembly process. The surface FeCo-LDH is then transformed into FeCo layered double oxide (LDO) with different compositions after calcination treatment (650 °C and 700 °C), forming a typical hierarchical structure. The sample calcined at 700 °C exhibited an ultra-wide effective absorption bandwidth (f) (RL < -10 dB) of 7.4 GHz (from 10.6 to 18.0 GHz) at the matched thickness of 2.2 mm. The remarkable EM wave absorption properties are attributed to the strong interface polarization due to the various phase boundaries in LDO shell as well as sufficient heterointerfaces between LDO shell and RCs. It should be emphasized that LDH is rarely used for EMW absorption, and the use of LDH positively charged characteristics to fabricate hierarchical materials is a meaningful attempt and confirms the potential of LDH in EMW absorbing materials.
过渡金属化合物（铁、钴和镍）一直是很有前景的电磁波吸收剂候选材料。在本研究中，通过简单的水热法和自发的静电自组装过程，合成了负载在树莓状碳球（RCs）上的铁钴层状双氢氧化物（LDH）。然后，经过煅烧处理（650°C和700°C）后，表面的FeCo-LDH转变为具有不同组成的铁钴层状双氧化物（LDO），形成典型的分级结构。在2.2mm的匹配厚度下，700°C煅烧的样品表现出7.4GHz（从10.6到18.0GHz）的超宽有效吸收带宽（f）（RL < -10dB）。显著的电磁波吸收性能归因于LDO壳层中各种相界引起的强界面极化以及LDO壳层与RCs之间足够的异质界面。应该强调的是，LDH很少用于电磁波吸收，利用LDH的带正电特性制备分级材料是一次有意义的尝试，并证实了LDH在电磁波吸收材料中的潜力。
