Developing a heat-insulating composite phase change material with light-to-thermal conversion performance from graphene oxide/silica hybrid aerogel

Phase change material (PCM) applied to solar energy storage should not only be concerned with light-to-thermal conversion performance but also consider heat loss. Therefore, a novel composite PCM with dual properties of light-to-thermal conversion and insulation was prepared in this work. Here, graphene oxide/silica hybrid aerogel with porous structure was synthesized using the sol-gel method, which has the advantages of low thermal conductivity and high specific surface area. The n-octadecanol (an organic PCM) was adsorbed into the hybrid aerogel to obtain composite PCM, which was then characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscope (FTIR), X-ray diffraction (XRD), differential scanning calorimeter (DSC) and thermogravimetric analysis (TG). The results showed that the composite PCM supported by hybrid aerogel had a higher heat storage capacity, with a maximum value of 145.6 J/g when the hybrid aerogel contained with 0.5 wt % GO. Moreover, the thermal conductivity of the composite PCM mentioned above is 0.0808 W/(m.K) which reduces by 72% compared with those of pure n-octadecanol (0.3015 W/(m.K)). Furthermore, the temperature of the as-prepared composite PCM could reach its melting point under irradiation conditions, indicating its good light-to-thermal conversion performance.