Preparation, characterization, stability, and thermal conductivity of rGO-Fe₃O₄-TiO₂ hybrid nanofluid: An experimental study

In the present study, ternary rGO-Fe₃O₄-TiO₂ nanocomposites was produced using a straightforward sol-gel technique. The nanofluids are synthesized using rGO-Fe₃O₄-TiO₂ hybrid nanoparticles suspended in ethylene glycol (EG). Ternary rGO-Fe₃O₄-TiO₂ nanocomposite (0.01–0.25 mass. %) were dispersed in EG acquiring stable nanofluids. The ternary rGO-Fe₃O₄-TiO₂ nanocomposite present in the colloidal phase has been categorized by FTIR, SEM, EDX, XRD, and Zeta potential. At varying temperatures between 25 and 60 °C, the thermal conductivity was explored. Experimental results show that the stability of all the studied rGO-Fe₃O₄-TiO₂ /EG nanofluid samples was above 52.04 mV. Enhancement in thermal conductivity for rGO-Fe₃O₄-TiO₂/EG nanofluids significantly increases with mass concentration and temperature, with an enhancement of 13.3% at 60 °C for 0.25 wt%. The best R² coefficient of determination estimated at 25 °C, 30 °C, 40 °C, 50 °C, and 60 °C was 95.6%, 98.2%, 95.4%, 97.6%, and 99.0%. Therefore, the investigated ternary hybrid nanofluid can be utilized for both heating and cooling applications with long term stability.