Effect of hollow structure on solar thermal applications of Au nanodiscs

Plasmonic nanoparticles (PNPs) with hollow structures have shown great potential for enhancing optical absorption. While spheres or cylinders are commonly used for PNPs, the study of hollow PNPs for direct absorption solar collectors is limited. This research investigates the impact of three different hollow structures (cylindrical - Case 1, square - Case 2, and trigonal - Case 3) on the optical absorption properties of Au nanodiscs. The findings demonstrate that the presence of hollow structures significantly enhances the photothermal conversion efficiency of Au nanodiscs. Specifically, Case 1, Case 2, and Case 3 exhibit photothermal conversion efficiencies that are 17.9%, 22.0%, and 16.8% higher, respectively, compared to standard Au nanodiscs. Notably, Case 2 demonstrates the highest optical absorption capacity and photothermal conversion efficiency among the three hollow structures. Through optimization, Case 2 achieves a remarkable photothermal conversion efficiency of 97.6%. Meanwhile, we also investigated the effect of continuously sharpening the hollow edges on the optical absorption properties of the nanodiscs. The continuous sharpening of the hollow core hampers both the enhancement of optical absorption properties and photothermal conversion properties in Au nanodiscs. Therefore, this research provides valuable theoretical insights for utilizing plasmonic nanoparticles with hollow structures to enhance photothermal conversion.