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

A novel nanohybrid comprised of magnetite (Fe3O4) nanocluster‐decorated reduced graphene oxide (RGO) nanosheets and its dispersions (nanofluids) were developed for heat transfer applications. The RGO/Fe3O4 nanohybrid was synthesized by a facile and cost‐effective one‐pot solvothermal route. The morphological, structural, chemical, and magnetic features of RGO/Fe3O4 nanohybrid was characterized by using various analysis techniques. To evaluate the efficacy of as‐synthesized nanohybrid for thermal engineering applications, stable water ‐based RGO/Fe3O4 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/Fe3O4 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 Fe3O4 (efficient conduction paths through zero‐field dipolar structures) components provided excellent stability and enhanced thermal conductivity to RGO/Fe3O4 nanofluids in the present study. The results demonstrate that RGO/Fe3O4 nanohybrid is a promising nanoadditive in designing efficient nanofluids for heat transport applications. Novel nanofluids containing magnetite (Fe3O4) nanocluster‐decorated reduced graphene oxide (RGO) nanosheets was synthesized by a simple one‐pot solvothermal process. Maximum 18 % enhancement in thermal conductivity was attained for water based RGO/Fe3O4 nanofluids even at a low nanohybrid volume fraction of 0.026. Nanofluids exhibited excellent dispersion stability which is prerequisite for their practical applications. The synergistic effects of RGO (large surface area, high inherent thermal conductivity, hydrophilic nature, and relatively low density) and Fe3O4 (efficient conduction paths through zero‐field dipolar structures) components provided excellent stability and enhanced thermal conductivity to RGO/Fe3O4 nanofluids in the present study.