Nonconvex Morphology of Metallic Copper Obtained via Nonclassical Crystallization of Copper Hydride

Copper particles with a desert rose morphology and high surface area were obtained via decomposition of a copper hydride whose particles possesses a similar shape. Copper hydride was synthesized by the reaction between copper sulfate and hypophosphorous acid at 50 °C. The different reaction steps of the copper hydride formation were monitored by two time-dependent techniques: in situ photon cross-correlation spectroscopy and ex -situ transmission electron microscopy. At the initial stage of the reaction, emulsion droplets of a particular size were formed, followed by the growth and agglomeration of copper hydride crystallites in the confinement of these droplets. The final structure consists of rose-like shaped particles with an average size of about 217 ± 53 nm arranged into chains. The surface area of these particles was estimated to be 41 ± 8 m²/g. The nucleation and growth of the copper hydride occur via a nonclassical crystallization pathway.