Light-induced plasmon-enhanced composite phase change materials for concurrent thermal energy storage and solar thermoelectric power generation

This study presents a plasmonically engineered composite phase change material (PCM) slurry for enhanced solar thermal energy storage (TES) and thermoelectric energy conversion via volumetric photothermal absorption. The system incorporates metal–organic core–shell nanoparticles dispersed in a PCM medium, enabling direct solar energy deposition throughout the fluid volume rather than surface-limited heating. The optical response of Ag, Au, Cu, and Al nanoshells is analyzed in terms of absorption and scattering characteristics, revealing strong plasmonic enhancement and tunable spectral behavior governed by shell composition and geometry. The results show that Ag-based structures provide the highest absorption efficiency in the visible range, while shell thickness and interfacial morphology significantly influence the transition between absorption- and scattering-dominated regimes, thereby controlling volumetric heat generation. Integration of plasmonic particles enhances TES by approximately 35–50% compared to a water-based reference, depending on PCM type and nanoparticle configuration. n-hexadecane and n-octadecane exhibit superior performance due to their high latent heat capacity and favorable phase transition behavior. Coupling the storage medium with a thermoelectric module demonstrates improved thermal gradient formation and energy harvesting capability, with power output exceeding that of conventional water-based systems. Overall, the study highlights the synergistic role of plasmonic volumetric absorption and latent heat storage in improving integrated solar thermal–thermoelectric system performance.