A combination of graphene, metal nanoparticles, and conductive polymers have been extensively studied for different applications such as degradation of pollutants. In particular, a combination of these materials can create synergetic effects that are ideal for the development of electromagnetic wave adsorbents. Graphene oxide is the widely used precursor for synthesis of graphene-based composites. However, the afterward chemical reduction reaction increases its preparation costs and the resulting products are environmental pollutants which limits their use. Thus, the development of alternative low-cost and environmentally friendly preparation methods for graphene-based composites is highly desirable. Recent studies have identified in situ intercalation polymerization method as a promising approach for synthesizing graphene composites owing to its success in the preparation of graphene oxide/PPy and graphene /PANI among others. Unfortunately, little has been reported about the one-step preparation of graphene-based composites using this method.
To this note, Xi’an Shiyou University researchers: Dr. Shaoli Guo, Dr. Junqing Wen, Dr. Lina Song, Dr. Jinfeng Qu, Dr. Wanlin He and Dr. Shuai Liu developed a one-step synthesis of graphene/ [email protected] ternary nanocomposites based on intercalation polymerization of aniline. Specifically, the morphology and formation mechanisms were investigated. In brief, the research team started by synthesizing the Graphene/[email protected] nanocomposites. The prepared products were then characterized using various methods including scanning electron microscope, and transmission electron microscope. Furthermore, the electromagnetic parameter was characterized by a vector network analyzer over a 2-18GHz frequency range. The paper is currently published in the research journal, Nanotechnology.
Results showed that, supported by sunlight exposure, the formation of the [email protected] nanostructure was due to Ag+ induced polymerization of aniline and self-reduction. This resulted in a further exfoliation of the graphite sheet into graphene attributed to the anchoring of the [email protected] nanoparticles onto the graphene surface to form a stable ternary structure. Additionally, the performance of graphene/[email protected] was comparable to its constituent micromorphology and depended on the Ag+/aniline ratio. The double-layer absorbers exhibited excellent absorption performance and recorded a reflection loss value of -44.5, -34.4, and -35.2db for DB-10, DB-5, and DB-1 absorbers respectively. It was worth noting that the high-frequency shift of the effective bandwidth was related to the increase of the dielectric constant of graphene/[email protected] as a result of graphene exfoliation.
In a nutshell, the scientists successfully synthesized graphene/[email protected] ternary composites in one step and found out that they possess excellent electromagnetic wave absorption property. A close relationship was observed between the Ag+/aniline ratio and the graphene exfoliation, Ag/PANI morphology, and the electrochemical properties of the composites. Being a facile, low-cost and environmentally friendly approach, Dr. Guo expressed her confidence that their research findings will be of great help not only in developing electromagnetic absorbing materials but also in exploring other potential applications of graphene /Ag/PANI in various areas such as pollutant degradation, supercapacitor electrodes, and high-efficiency sensors among others.
Guo, S., Wen, J., Song, L., Qu, J., He, W., & Liu, S. (2020). One-step fabrication and electromagnetic wave absorption of graphene/[email protected] ternary nanocomposites. Nanotechnology, 31(22), 225606.