Copper sulfide self-assembly architectures with improved photothermal performance.

Copper chalcogenide nanomaterials are promising photothermal materials for establishing novel diagnostic and therapeutic methods owing to the low cost but high photothermal transduction efficiency. Further progresses of the correlated technologies greatly depend on the efforts on design and construction of novel nanostructures. In this paper, we demonstrate a facile one-pot route for constructing CuS nanostructures in aqueous media via a spontaneous assembly process. In the presence of polyvinylpyrrolidone (PVP) as the capping agents, a decomposition of Cu(CH3COSH)x precursors is induced by ammonia, which produces hexagonal CuS nanoparticles (NPs) with the diameter around 22 nm. The primary CuS NPs greatly tend to self-assembly into one-dimensional structures, which are triggered by short-range anisotropic dipolar attraction and enforced by long-range isotropic electrostatic repulsion. The further fusion of the assembled NPs generates 480 × 50 nm(2) CuS nanorods. Because the formation of nanorods enhances the internanorod van der Waals attraction, the nanorods finally self-assembly into shuttle-like bundles in micrometer size. In comparison to isolated NPs, the regular CuS assembly structures exhibit improved molar extinction coefficient up to 9.7 × 10(16) cm(-1) M(-1) by shortening the distance of neighboring CuS NPs and therewith generating new electronic structures of the CuS indirect transition. Consequently, better photothermal performance is achieved.