Synthesis of hybrid materials based on reduced graphene oxide and Ni (NiO) nanoparticles by supercritical solvent and thermal treatment techniques

Abstract

Functional hybrid nanomaterials on the basis of reduced graphene oxide (RGO) and metal-containing nanoparticles (NPs) are of increasing interest due to their tunable physical and chemical properties. In this study, we comparatively evaluate a simultaneus synthesis of hybrides through thermal reduction and supercritical isopropanol (SCI) treatment utilizing nickel acetylacetonate as a metal precursor and graphene oxide to form metal-based nanoparticles on the surface of RGO. SCI treatement yields the formation of metallic nickel NPs with an average diameter of 11 nm on the RGO surface, whereas thermal reduction facilitate appearance of nickel oxide (NiO) NPs with an average size of 5 nm on the surface of partially reduced graphene oxide. Hybrid materials produced by treatment in SCI exhibits good conductive and magnetic properties. Both surface resistance and saturation magnetization (Ms) strongly depend on the content of metal NPs in the hybrid. The maximum Ms value for RGO hybrids syntesized by SCI was 13.9 emu/g. These materials hold potential for flexible electronics, piezomagnetic sensors, and catalysis applications.