Microwave Absorption Properties of CoS₂ Nanocrystals Embedded into Reduced Graphene Oxide

Abstract

CoS nanoparticles and CoS/reduced graphene oxide (CoS/rGO) nanohybrids were fabricated by a unique single-mode microwave-assisted hydrothermal method. The microwave absorption properties of CoS/rGO composites with different rGO proportions were investigated. Morphology analysis indicated that the CoS nanoparticles were uniformly embedded into rGO without aggregation. The complex permittivity of CoS/rGO nanohybrids could be artificially tuned with the rGO proportions. For the CoS/rGO 1:2 composite, the minimum reflection loss (RL) of -56.9 dB was achieved at 10.9 GHz for the thickness of 2.2 mm; meanwhile, the RL exceeding -10 dB were obtained in the frequency range of 9.1-13.2 GHz. Compared with other rGO-based materials, CoS/rGO composite exhibited superior microwave absorption ability at a rather thin thickness and it has great potential to be used as a high-efficiency and tunable microwave absorber.

Economical synthesis of composites of FeNi alloy nanoparticles evenly dispersed in two-dimensional reduced graphene oxide as thin and effective electromagnetic wave absorbers

“…1,9,30 Meanwhile, the abundant functional groups and defects residing on the sheets of rGO render to this material modest electric conductivity and optimistic polarization as a potential EM wave absorber. 31 To satisfy the impedance matching conditions, magnetic/rGO-based composites have been investigated to pursue an improved microwave absorption capability.…”

“…[1][2][3][4] The various kinds of absorbers are normally classied into two categories: dielectric materials and magnetic materials, which have been successfully synthesized to ease electromagnetic (EM) wave pollution by means of absorbing unwanted electromagnetic signals.…”

Microwave Synthesized In2S3@CNTs with Excellent Properties inLithium‐Ion Battery and Electromagnetic Wave Absorption

“…Many chalcogenide materials, such as MoS 2 , CoS 2 , NiS 2 , have been reported as an electromagnetic wave absorber with high RL (above -40 dB). [2,44,45] The thickness of In 2 S 3 @CNTs nanocomposite is less than that reported in literatures (MoS 2 , [44] MoS 2 /rGo, [46] CoS 2 /rGo, [2] NiS 2 @MoS 2 [45] ). The RL value less than -10 dB (electromagnetic wave absorption 90%) can be realized with bandwidth of 4.4 GHz at the In 2 S 3 @CNTs nanocomposite thickness of 1.27 mm.…”

“…tan (2) where Z 0 is the impedance of air, ε r (ε r ＝ε r 'jε r '') and μ r (μ r ＝ μ r 'jμ r '') are the complex permittivity and permeability, respectively, d is the thickness of absorbers, c is the speed of light and f is the frequency of electromagnetic wave. The RL color maps of In 2 S 3 @CNTs nanocomposite and In 2 S 3 as function of frequency and thickness are shown in Figure 4(c) and Figure 4(d), respectively.…”

“…Nanomaterials, with the advantages of large specific surface area, high surface energy, large proportion of surface area, have been widely studied in energy, information, electromagnetic wave absorbing and other fields. [1][2][3][4][5] Recently, many nanometal sulfides have been put forward as lithium ion batteries (LIBs) anode materials. Compared with nanometal oxide semiconductor materials as traditional electrode materials for promising candidate of commercial graphite (372 mAhg -1 ), the nanometal sulfides also have a high specific capacity, such as In 2 S 3 , [6] WS 2 , [7,8] MoS 2 , [9] SnS 2 [10] and other related nanomaterials.…”