New functional graphene oxide based on transition metal complex (Cr/Fe) as wave absorber

Abstract

In this article, the graphene oxide (GO) was produced from graphite by the “modified hammer” method. Then in order to achieve electromagnetic absorption, GO was reduced and modified two times. First, it was reduced and modified by Cr, and then for the second time, it reduced and remodified in a one-step process with FeCl2 and FeCl3. All the synthesized materials were characterized via SEM, TEM, XRD, FTIR, Raman spectroscopy. These methods showed that in each stage Cr-RGO and Fe–Cr-RGO were successfully produced and the method that has been used was prosperous. To investigate prominent electromagnetic (EM) absorption, every specimen was added to the epoxy matrix with different concentrations and molded with different thicknesses. To perfectly disperse modified reduced graphene oxides powder in the epoxy resin, a unique liquid Ions (Butyl methyl imidazolium bromide) was used. This product has a key role in dispersing the material into the matrix and in the meantime the resulted composites showed a better return loss (RL) in the network analyzer tests. With a series of tests and precise measurements, the optimum thickness and concentration of Cr-RGO or Fe–Cr-RGO to reach the maximum EM absorption were developed. The result shows that by increasing the concentration and the thickness of the specimens, electromagnetic absorption increases and this phenomenon has happened almost in the complete range of our desire microwave (MW) wavelengths (2–12 GHz).