A Facile Synthesis of Novel Amorphous TiO2 Nanorods Decorated rGO Hybrid Composites with Wide Band Microwave Absorption

Abstract

Amorphous structures may play important roles in achieving highly efficient microwave absorption performance due to the polarization losses induced by the disorders, vacancies and other functional groups existed in them. Herein, a kind of amorphous TiO2/rGO composite (a-TiO2/rGO) was successfully fabricated via a facile one-step solvothermal method. The complex permittivity of the composites can be regulated by adjusting the addition of precursor solution. The minimum reflection loss of a-TiO2/rGO composites reached −42.8 dB at 8.72 GHz with a thickness of 3.25 mm, and the widest efficient absorption bandwidth (EAB) was up to 6.2 GHz (11.8 to 18 GHz) with a thickness of only 2.15 mm, which achieved the full absorption in Ku band (12 to 18 GHz). Furthermore, the EAB was achieved ranging from 3.97 to 18 GHz by adjusting the thickness of the absorber, covering 87.7% of the whole radar frequency band. It is considered that the well-matched impedance, various polarization processes, capacitor-like structure and conductive networks all contributed to the excellent microwave absorption of a-TiO2/rGO. This study provides reference on constructing amorphous structures for future microwave absorber researches and the as-prepared a-TiO2/rGO composites also have great potential owing to its facile synthesis and highly efficient microwave absorption.

Enhanced microwave absorption properties of reduced graphene oxide/TiO2 nanowire composites synthesized via simultaneous carbonation and hydrogenation

“…To investigate the MA properties of the prepared RGO/h-TiO 2nw composites, reflection loss (RL) values are calculated on the basis of relative complex permittivity ( ε r = ε ′ − jε ′′) and relative complex permeability ( μ r = μ ′ − jμ ′′) at a given frequency and absorber thickness according to the transmit line theory: 46 where Z 0 is the impedance of free space, Z in is the input impedance of the absorber, f is the frequency of the microwave, d is the thickness of the absorber, and c is the velocity of light. Fig.…”

“…RGO/h-TiO 2nw composites synthesized in this study, outperform all other reported materials with outstanding RL values and ultralow filler contents in the paraffin matrix, and are accompanied by a broad EAB. 9,18,24,28,31,38,43,46,51–55…”

“…RGO/h-TiO 2nw composites synthesized in this study, outperform all other reported materials with outstanding RL values and ultralow filler contents in the paraffin matrix, and are accompanied by a broad EAB. 9,18,24,28,31,38,43,46,[51][52][53][54][55] Based on the aforementioned analysis, the associated mechanisms for the improved MA performance of RGO/h-TiO 2nw composites could be concluded and are illustrated in Fig. 10.…”

Structural Engineering of Hierarchical Aerogels Comprised of Multi-dimensional Gradient Carbon Nanoarchitectures for Highly Efficient Microwave Absorption

“…8 b, c) are also consistent with this viewpoint. At present, most researchists have agreed that the conductivity of the sample is closely related to the crystal structure and morphology of materials [ 82 – 86 ]. In this case, the crystal structure of CNC is almost amorphous (Fig.…”

Ultralight MOF-Derived Ni3S2@N, S-Codoped Graphene Aerogels for High-Performance Microwave Absorption

“…In order to explore multiple loss mechanisms in Ni 3 S 2 @NSGA-650, the curves of ε" versus ε were plotted in Figure 6d. The curve can be easily divided into two parts-one is a straight line with larger ε related to the conduction loss, which mainly stems from the migration of electrons in a 3D interconnected network structure [22,23]; the other is several semicircles with smaller ε with respect to the polarization loss [32,33]. The multiple polarization relaxations in Ni 3 S 2 @NSGA-650 include the dipolar polarizations at the defect and functional groups on the N, S-codoped rGO skeleton, and heterogeneous interfacial polarizations among Ni 3 S 2 nanoparticles and graphene sheets.…”