Multishell Copper Oxide Hollow Spheres Incorporated with Fatty Amines for High Light-To-Thermal Conversion

Composite phase change materials (PCMs) are of great importance for the storage and conversion of energy. In this study, a multishell metal oxide hollow microsphere (CuOHS) was prepared by the hydrothermal method, and a new composite PCM (CuOHS@PCMs) for energy storage and conversion purposes was developed by effectively absorbing fatty amines [namely, tetradecylamine (TDA), hexadecylamine (HDA), and octadecylamine (ODA)] PCMs into the CuOHS via the abundant micropores located on the surface of the microsphere. The incorporation of uncontaminated phase alteration substances with CuOHS yields superior light absorption and leak prevention traits. The three CuOHS@PCMs, specifically CuOHS@TDA, CuOHS@HDA, and CuOHS@ODA, possess considerable latent heats of 198.8, 192.6, and 196.0 J·g^-1, respectively, and exhibit desirable thermal properties even after completing 50 and 100 thermal cycles. Moreover, under illumination, the photothermal conversion efficiencies of the three variations of CuOHS@PCMs were 84.0, 81.4, and 78.0%. This CuOHS@PCMs, which are based on CuOHS, have considerable potential in the fields of photothermal conversion, solar energy harvesting, and storage.