Fabrication of novel Cu microspheres assembled with nanoparticles by a solvothermal reduction route

Copper microspheres assembled with nanoparticles have been synthesized by a simple solvothermal route at 160 °C for 24 h. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectrometer (EDX), transmission electron microscopy (TEM) and electron diffraction (ED) techniques. The results show that the diameters of the microspheres range from 2 to 4 μm. The formation mechanism of the morphology control over the copper microspheres assembled by nanoparticles was investigated; the use of polyvinylpyrrolidone (PVP) as the surfactant and the choice of N,N-dimethylformamide (DMF) as the reducing agent were found to be important for the final generation of copper microspheres.