Effect of copper oxide/cobalt oxide nanocomposite on phase change material for direct/indirect solar energy applications: Experimental investigation

In this piece of work, an attempt to solve the global energy crisis by presenting advanced thermal energy storage technology was experimentally investigated. To enhance the thermal performance of paraffin wax as phase change material (PCM), nanoparticles (NPs) were utilized at 3% wt. concentration in mono and hybrid form: copper oxide (CuO) NPs, cobalt oxide (Co₃O₄) NPs, and CuO@Co₃O₄ nanocomposite (NC). All the fabricated materials were detailly characterized via SEM, TEM, XRD, FT-IR, and DSC analyses. Beyond, outdoor experiments, under direct/indirect solar exposure, were conducted to determine the thermal performance of the nano-enhanced PCM specimens compared to pure PCM. For each experiment, direct/indirect solar absorption, four specimens were prepared: pure paraffin wax, nano-CuO-enhanced paraffin wax, nano-Co₃O₄-enhanced paraffin wax, and nano-CuO@Co₃O₄-enhanced paraffin wax. As result, all nano-based PCM cases had better performance than pure PCM. Among them, the nano-CuO@Co₃O₄-enhanced PCM recorded the highest temperature, at noon, with an enhancement ratio of 14.15% compared to that of pure paraffin wax.