In-situ gold/gold nanorods/graphene nanoplatelets-enhanced phase change materials with superior solar thermal conversion and deicing capability

Solar thermal conversion and storage technologies utilizing phase change materials are promising for meeting future energy demands and imbalances because of their exceptional energy storage capability and reversibility. However, effectively improving photothermal conversion performance and skillfully harnessing photothermal energy remain considerable challenges. Herein, hybrid photothermal fillers were created by in-situ growth of gold and gold nanorods on graphene nanoplatelets to endow phase change materials with superior solar thermal conversion properties, and an innovative photothermal deicing method for domestic water systems was devised. Morphological and structural analyses confirmed the successful in-situ synthesis of the hybrid nanofillers, which induced a bimodal localized surface plasmon resonance effect and broadened the spectral absorption range, leading to a 35.3 % increase in the light absorption for phase change composites. Moreover, experiments indicate that the solar thermal conversion and storage efficiencies of the phase change composites reach 82.8 % and 45.7 %, respectively, which is because more light absorption centers provided by hybrid nanofillers effectively enhance solar capture and absorption while reducing heat dissipation and non-radiative losses. Furthermore, numerical simulations demonstrate that the deicing time of the phase change composite-coated pipe is 38.3 % shorter than that of the uncoated pipe, and the deicing time can be significantly reduced by 78.9 % with concentrated light at 3000 W/m², indicating that the superior photothermal deicing performance and potential applications of the proposed phase change composites. The findings shed novel light on the development of functional photothermal phase change composites and innovative solar thermal utilization systems.