Aniline-functionalized rGO/polyaniline hybrids: A synergistic approach for enhanced microwave absorption

In pursuit of lightweight and flexible microwave-absorbing materials, reduced graphene oxide (rGO)/polyaniline (PANI) hybrids exhibit immense potential due to their synergistic dielectric properties. This study presents a novel one-pot strategy for the covalent functionalization of graphene oxide (GO) with aniline, followed by reduction to yield aniline-functionalized rGO (Ani-rGO). This approach effectively mitigates the intrinsic limitations of pristine rGO, including agglomeration and suboptimal impedance matching. Subsequently, rGO/PANI composites were synthesized via in-situ polymerization of aniline in the presence of varying Ani-rGO concentrations, utilizing citric acid as an environmentally benign dopant. The covalent bonding formation into the rGO/PANI hybrids was confirmed through Fourier transform infrared spectra (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and morphology by field emission scanning electron microscope (FESEM). The covalent integration of PANI nanorods onto the Ani-rGO framework facilitated enhanced charge transport, interfacial polarization, and dielectric loss, culminating in superior microwave absorption (MA) performance. The optimized composite achieved a minimum reflection loss (RL) of −47.09 dB at 9.63 GHz with an effective absorption bandwidth (EAB) of 3.51 GHz at a 2 mm thickness, significantly outperforming pristine rGO and Ani-rGO. These findings underscore the efficacy of Ani-rGO/PANI hybrids as advanced electromagnetic interference (EMI) shielding materials, offering a strategic pathway for developing next-generation lightweight, high-performance microwave absorbers.