Synthesis of carbon nanotube-MgO composite by chemical vapour deposition for thermal energy storage

The aim of this study was to synthesise a nanocomposite structure to be used together with phase change materials (PCMs) for thermal energy storage (TES) applications. This structure is composed of the thermally conductive carbon nanotubes (CNT) connected to MgO, i.e. a ceramic material known to have good compatibility with PCMs. Such interconnection is developed by growing CNT directly on MgO by chemical vapour deposition (CVD) with the aid of a small amount of Co nanoparticles deposited on the surface of MgO that acts as a catalyst for the growth. The deposition of Co on MgO was carried out using a wet impregnation method. A scanning electron microscope (SEM) and energy-dispersive x-ray spectrometer (EDS) were utilised to observe the dispersion of Co on MgO. CVD growth of CNT was conducted at 800°C under the flow of methane (50 mL/min) and nitrogen (100 mL/min) for 30 min. From the study, the interconnection between CNT and MgO was clearly seen under SEM and uniform dispersion of CNT in the composite structure was observed. The approach used in this work would be crucial to minimise the thermal contact resistance due to the established interconnection between CNT and MgO, thus can bring about enhancement to the thermal conduction in TES.