The synthesis of Cu/plate-like ZnO nanostructures and their self-assembly mechanism

The copper oleate firstly decompose at low temperature, and is self-reduced into irregular Cu nanoparticles. Meanwhile, zinc oleate remains unchanged and the oleate ion acts as protection agent for the Cu nanoparticles. When the reaction temperature is raised up to 290 °C, zinc oleate begins to decompose and ZnO nanoparticles are generated with regular size and shape and wrapped by Cu nanoparticles. Finally, the small ZnO particles further self-assemble into hexagonal disc-like structures with Cu nanoparticles on their surfaces. In this growth process, oleate ions play two important roles: 1) reducing Cu ion and 2) wrapping Cu nanoparticles to make them stable.160