Renewable energy efficiency can be increased using phase change materials (PCMs). This study has successfully developed PCMs with supporting materials, such as SiO2, Fe3O4, and graphene. Briefly, the synthesis of Fe3O4–Graphene/polyethylene glycol (PEG)–SiO2 begins with the synthesis of Fe3O4–Graphene using the coprecipitation method. Next, Fe3O4–Graphene/PEG–SiO2 nanocomposites are prepared with Fe3O4–Graphene mass varied in a range of 5%–8%. Based on the results, the Eg value of the Fe3O4–Graphene is 1.73 eV. The morphology of Fe3O4–Graphene/PEG–SiO2 shows that Fe3O4 particles stick to the surface of the graphene sheet. The addition of Fe3O4–Graphene mass affects the saturation magnetization value, which increases with an increase in Fe3O4–Graphene within the range of 1.05–2.55 emu/g. In addition, the latent calorific value obtained by differential scanning calorimetry shows that all the samples have a phase transition range within a temperature range of 59.4°C-60.5 °C and a latent calorific value of >100 J/g. Owing to its high latent calorific value, Fe3O4–Graphene/PEG–SiO2 can be applied as a heat-storage material.
- Latent heat