Eco-friendly synthesis of high electrical conducting graphene oxide through a hydroxylation reaction for composite applications

Graphene oxide (GO-E) with high electrical conductivity was eco-friendly synthesized through a hydroxylation reaction in water. The graphite was oxidized via hydroxylation of the alkene groups in a deionized (DI) water to obtain graphite oxide (O-Gr). The O-Gr was mechanically exfoliated into GO-E by applying shear force with a homogenizer in a polar solvent. The GO-E was highly dispersible in a polar solvent in single- or few-layered GO-E sheets with an average area of 580 μm2. The Raman intensity ratio of the G-band to D-band (ID/IG) demonstrates that the hydroxylation reaction can produce GO-E with less defects compared to the Hummer's method (GO-H). Furthermore, the GO-E exhibited a high electrical conductivity of 760 S/m, which was much higher than that of GO-H. The GO-E and GO-H filled Polyimide (PI) composites were prepared by the in-situ polymerization and the GO-E/PI composite showed higher electrical conductivity than that of GO-H/PI composite. Thus, this approach provides us a simple, efficient and eco-friendly synthesis way of GO with high electrical conductivity for composite applications.