Constructing heterostructural Fe@Fe3C@carbon nanotubes/reduced graphene oxide nanocomposites as lightweight and high-efficiency microwave absorbers

Abstract

To take advantage of the double loss mechanism, multiple interface structures and fascinating properties of carbon materials, we propose a simple strategy to elaborately design and produce the heterostructural Fe@Fe₃C@carbon nanotubes (CNTs)/reduced graphene oxide (RGO) nanocomposites by a combined method of hydrothermal reaction and chemical vapor deposition. Owing to the regulation of CNTs’ content, the results indicate that the electromagnetic (EM) and EM wave absorption properties of designed nanocomposites could be regulated by the decomposition temperature. The as-prepared Fe@Fe₃C@CNTs/RGO nanocomposites simultaneously presented extremely strong absorption capabilities and large absorption bandwidth with very thin matching thicknesses (d_m). In particular, the samples obtained at 500 and 550 °C simultaneously displayed very low minimum reflection loss (RL_min) values of −62.29 dB at 15.16 GHz with the d_m value of 1.79 mm and −74.31 dB at 11.56 GHz with the d_m value of 2.14 mm. Their effective frequency bandwidth (f_b) values were 6.00 GHz with the d_m value of 1.87 mm and 6.00 GHz with the d_m value of 1.85 mm. Compared to the previously reported representative related microwave absorbers (MAs), the designed heterostructure Fe@Fe₃C@CNTs/RGO nanocomposites, which could be utilized as good lightweight and high efficiency Mas, displayed superior comprehensive EM wave absorption properties. The results presented a new and effective strategy to construct high-performance MAs.