High-Speed Synthesis of Rice-Ear-Shaped Cu Dendritic Particles at Room Temperature via Galvanic Displacement Using Zn Particles

Rice-ear-shaped Cu dendritic particles were fabricated via fast galvanic displacement reactions for 3–5 min under ambient conditions by adding Zn particles into an aqueous electrolyte without chloride ions. The obtained Cu dendritic particles have a small average size (4.44 μm) and short, multiple branches that seemed to be aggregates of nanoparticles formed on stem-like backbones, and their surface area is large. The prepared Cu dendrites could be protected against oxidation during drying via post-treatment with chelating or complexing agents. While the dendrite stem is found to be a Cu polycrystal grown only on the (111) plane, the branches consist of three planes of Cu, viz., (111), (200), and (220), indicating that they were formed by random attachment of nanoparticles and aggregates. A possible low-temperature and high-speed synthesis mechanism is proposed based on the results of time-dependent SEM investigations as well as the crystal structure of the dendrites. This novel technique to synthesize modified dendrites is extremely simple and suitable for mass production.