Hierarchical CuS Nanostructures Prepared by Hydrothermal Decomposition for Photothermal Water Evaporation

Photothermally active nanomaterials have attracted significant interest due to their efficient light‐to‐heat conversion, enabling a wide range of applications. Among them, nanostructures of binary copper sulfides (Cu 2– x S, where 0 ≤ x ≤ 1) are particularly promising for near‐infrared (NIR)‐driven photothermal applications because of their strong NIR absorption arising from plasmonic behavior. Within the Cu 2– x S family, CuS (covellite) exhibits the most pronounced plasmonic response, making it an attractive platform for NIR photothermal conversion. In this work, we demonstrate a simple synthesis strategy for CuS nanostructures based on the hydrothermal decomposition of bis(diethyldithiocarbamato)copper(II), a readily accessible single‐source precursor. The resulting materials are hierarchical structures composed of nanoplate subunits, whose thickness and stacking behavior are influenced by polyvinylpyrrolidone. These hierarchical CuS nanostructures exhibit intense NIR extinction features and excellent photothermal activity and stability, which were successfully exploited for NIR‐driven interfacial water evaporation.