School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, P. R. China.
Dalton Trans. 2018 Oct 23;47(41):14767-14773. doi: 10.1039/c8dt03282c.
In this work, novel one-dimensional (1D) Mo2C/Co@C nanorods (MCRs), using a metal-organic framework (zeolitic imidazolate framework; ZIF-67) as the coating layer to form multi-interfaces, were formed via a facile hard template method. Compared with previous works relating to porous-carbon-based Mo2C nanocomposites, the well-designed MCRs in this study possess a double attenuation mechanism due to the existence of the dielectric materials Mo2C and remaining carbon (RC) and the magnetic compound Co. Thanks to a new design and the multiple useful compounds, the as-prepared MCRs have the features of demonstrating multi-interfacial polarization, a large surface area and highly isotropic dissipation. Hence, the samples not only inherit the excellent microwave absorbing abilities of Mo2C but they also have a broadened effective bandwidth. For example, the minimum reflection loss (RL) value of MCRs with 35% sample loading could reach -47.98 dB. More importantly, RL values of less than -10 dB can be observed from 11.08 to 17.08 GHz (an effective bandwidth of 6.0 GHz) with a matching thickness of 1.6 mm, which is much better than previous work involving porous-carbon-based Mo2C nanocomposites. Firstly, we have reasonably redesigned the samples to have good absorbing properties for practical applications. Secondly, we have paved a highly efficient and universal way to synthesize 1D microwave absorbers with multiple valuable interfaces.
在这项工作中,通过一种简便的硬模板法,形成了新型一维(1D)Mo2C/Co@C 纳米棒(MCRs),使用金属有机骨架(沸石咪唑酯骨架;ZIF-67)作为涂层以形成多界面。与之前有关多孔碳基 Mo2C 纳米复合材料的工作相比,本研究中设计良好的 MCRs 由于介电材料 Mo2C 和剩余碳(RC)和磁性化合物 Co 的存在,具有双重衰减机制。由于新的设计和多种有用的化合物,所制备的 MCRs 具有表现出多界面极化、大表面积和各向同性耗散的特点。因此,这些样品不仅继承了 Mo2C 的优异微波吸收能力,而且具有更宽的有效带宽。例如,在 35%样品负载下,MCRs 的最小反射损耗(RL)值可达到-47.98 dB。更重要的是,在 1.6mm 的匹配厚度下,从 11.08GHz 到 17.08GHz(有效带宽为 6.0GHz)可以观察到 RL 值小于-10dB,这比之前涉及多孔碳基 Mo2C 纳米复合材料的工作要好得多。首先,我们合理地重新设计了样品,使其具有良好的吸收性能,以满足实际应用的需求。其次,我们开辟了一种高效且通用的方法来合成具有多个有价值界面的 1D 微波吸收剂。