A New Broadband and Strong Absorption Performance FeCO3/RGO Microwave Absorption Nanocomposites

Abstract

A novel composite of FeCO3 nanoparticles, which are wrapped with reduced graphene oxide (RGO), is fabricated using a facile one-spot solvothermal method. The composite consists of a substrate of RGO and FeCO3 nanoparticles that are embedded in the RGO layers. The experimental results for the FeCO3/RGO composite reveal a minimum refection loss (−44.5 dB) at 11.9 GHz when the thickness reaches 2.4 mm. The effective bandwidth is 7.9 GHz between 10.1 and 18 GHz when the refection loss was below −10 dB. Compared to GO and RGO, this type of composite shows better microwave absorption thanks to improved impedance matching. Overall, this thin and lightweight FeCO3/RGO composite is a promising candidate for absorbers that require both strong and broad absorption.

Mechanistic Insights into the Phase Formation of an Atypical Iron Oxynitride (FexOyNz) System and Its Multifunctional Photocatalytic Applications

“…The deconvoluted Fe 2p XPS spectrum of FO sample shows the peaks corresponding to Fe 2p 3/2 and Fe 2p 1/2 at 710.1 and 723.4 eV, 44,45 with a spin−orbit splitting energy difference of 13.3 eV along with corresponding satellite peaks. 46 These observations reveal that the Fe ions possess a stable +3 oxidation state, which confirms the formation of the α-Fe 2 O 3 phase as determined by its XRD pattern. On the other hand, in the FN spectrum, the peaks corresponding to Fe 2p 3/2 and Fe 2p 1/2 appeared at 710.3 and 723.7 eV (with orbital splitting energy of 13.4 eV) with hardly any visible satellite peaks, indicating that Fe in the iron nitride phase possesses higher multiple-oxidation states (+3/+4) to form Fe x N phases as confirmed from its XRD pattern.…”

“…All the XPS spectra are calibrated by taking the standard C 1s peak at 284.6 eV. , The XPS spectra of Fe in the synthesized iron oxide, nitride, and oxynitride samples are shown in Figure b. The deconvoluted Fe 2p XPS spectrum of FO sample shows the peaks corresponding to Fe 2p 3/2 and Fe 2p 1/2 at 710.1 and 723.4 eV, , with a spin–orbit splitting energy difference of 13.3 eV along with corresponding satellite peaks . These observations reveal that the Fe ions possess a stable +3 oxidation state, which confirms the formation of the α-Fe 2 O 3 phase as determined by its XRD pattern.…”

Effect of Solvothermal Reaction-Time on Microstructure and Microwave Absorption Properties of Cobalt Ferrite

“…In order to visually describe the effect of reaction time on the microwave absorption performance, a three-dimensional model (return-loss/frequency/thickness) was established according to the transmission line theory [ 27 , 28 ]: …”

“…Furthermore, the attenuation ability and impedance matching characteristics of the material should be considered. In order to visually describe the effect of reaction time on the microwave absorption performance, a three-dimensional model (return-loss/frequency/thickness) was established according to the transmission line theory [27,28]:…”

“…When the reaction time is 12h, at the same thickness, the effective absorption bandwidth is 4.96 GHz (6.32-11.28 GHz), with a minimum return loss of −15.27 dB. When the response time is 16h, the effective absorption bandwidth is 6.8G Hz (6.24-13.04 GHz), with a In order to visually describe the effect of reaction time on the microwave absorption performance, a three-dimensional model (return-loss/frequency/thickness) was established according to the transmission line theory [27,28]:…”