Facile One-Pot Solvothermal Synthesis of the RGO/MWCNT/Fe₃O₄ Hybrids for Microwave Absorption

Abstract

How to effectively regulate the electromagnetic parameters of magnetic composites to achieve better microwave absorption (MA) performances is still a serious challenge. Herein, we constructed nanocomposites composed of magnetic constituents and carbon materials to obtain high-efficiency electromagnetic wave absorbers. Self-assembled, multi-interfacial, and porous RGO/MWCNT/Fe3O4 hybrids (GMFs) were synthesized via in situ one-pot solvothermal method. The growth mechanism of the GMFs would be that the defects on reduced graphene oxide (RGO) provide sites for the crystallization of Fe3O4. Also, the RGO and Fe3O4 were further linked by the cross-connection of multiwalled carbon nanotubes (MWCNTs), which acted as a bridge. The MA mechanism of GMFs was studied while considering the synergistic effects between the three components (RGO, MWCNT, and raspberry-shaped Fe3O4) and their multi-interfacial and porous structure. Also, the MA performance of the GMFs was conducted. The GMFs exhibited a maximum reflection loss (RL) value of −61.29 dB at 10.48 GHz with a thickness of 2.6 mm when the contents of RGO and MWCNT were 6.3 and 1.3 wt %, respectively. The RL values (≤−10 dB) were observed to be in the range of 8.96–12.32 GHz, and the effective microwave absorption bandwidth was tunable from 3.52 to 18 GHz by changing the sample thickness. The results revealed that the multi-interfacial and porous structure of the GMFs is beneficial to MA performance by inducing multiscatterings. Since no toxic solvents were used, this method is environmentally friendly and has potential for large-scale production. The prepared GMFs may have a wide range of applications in MA materials against electromagnetic interference pollution.

Fundamental Insight into the Degradation Mechanism of an rGO-Fe3O4 Supercapacitor and Improving Its Capacity Behavior via Adding an Electrolyte Additive

“…The D band around 1343 cm –1 is attributed to the presence of chaotic graphite structures caused by amorphous carbon and defects, which stems from the symmetric A 1g model of defective graphite. The G band near 1571 cm –1 is derived from the tangential in-plane tensile vibration of the C–C band, which is attributed to the E 2g graphite model. − In addition, the intensity of the G-band is stronger than the intensity of the D-band, and the intensity ratio of the D-band and G-band ( I D / I G ) is used to evaluate the degree of modification or defect of the rGO . The Raman results confirmed that the prepared rGO-Fe 3 O 4 composites have a lower I D / I G ratio, exhibiting an ordered crystalline structure in the presence of fewer structural defects. − The overall XRD patterns for reduced graphene oxide (rGO), pure Fe 3 O 4 NPs, and rGO-Fe 3 O 4 composites are shown in Figure e.…”

The Effect of Surface Roughness of Magnetic Particles on the Electromagnetic Wave Absorbing Performance of Fe3O4/Multiwalled Carbon Nanotubes Hybrids

“…Zhou synthesized a new absorbing material of RGO/ MWCNT/Fe 3 O 4 hybrids (GMFs). [15] The GMFs exhibited the reflection loss (RL min ) value is À 61.29 dB. The above results show the incorporation of dielectric loss materials with magnetic loss materials would improve the absorption performance.…”

Bimetallic Oxalate Rod-Derived NiFe/Fe3O4@C Composites with Tunable Magneto-dielectric Properties for High-Performance Microwave Absorption

“…Dielectric loss and magnetic loss tangent are crucial parameters to determine the dominating loss mechanism in the microwave absorbing mechanism . As shown in Figure a, ε′ decreases gradually from 2 to 18 GHz, which may be caused by the frequency-dispersion phenomenon . Both ε′ and ε″ decrease from NFCR-500 to NFCR-700 with the carbothermal reduction temperature increase.…”