Novel Nanohybrid Containing Magnetite Nanocluster‐Decorated Reduced Graphene Oxide Nanosheets for Heat Transfer Applications

Abstract

A novel nanohybrid comprised of magnetite (Fe 3 O 4 ) nanocluster-decorated reduced graphene oxide (RGO) nanosheets and its dispersions (nanofluids) were developed for heat transfer applications. The RGO/Fe 3 O 4 nanohybrid was synthesized by a facile and cost-effective one-pot solvothermal route. The morphological, structural, chemical, and magnetic features of RGO/Fe 3 O 4 nanohybrid was characterized by using various analysis techniques. To evaluate the efficacy of as-synthesized nanohybrid for thermal engineering applications, stable water -based RGO/Fe 3 O 4 nanofluids were synthesized and their thermal conductivity (k) was measured as a function of volume fraction (ϕ). Maximum 18 % enhancement in k value was attained for RGO/Fe 3 O 4 nanofluids even at a low nanohybrid concentration of ϕ = 0.026. The synergistic effects of RGO (large surface area, high inherent k, hydrophilic nature, and relatively low density) and Fe 3 O 4 (efficient conduction paths through zero-field dipolar structures) components provided excellent stability and enhanced thermal conductivity to RGO/Fe 3 O 4 nanofluids in the present study. The results demonstrate that RGO/Fe 3 O 4 nanohybrid is a promising nanoadditive in designing efficient nanofluids for heat transport applications.