CuO nano/microspheres with a wide diametric distribution were prepared by thermal decomposition of Cu-2(OH)(3)NO3 nano/microspheres formed in a simple asymmetric-electrode based cathodic-plasma electrolysis. The morphological, componential, and structural information about the two kinds of spheres were characterized in detail by SEM, TEM, EDX, XPS and XRD, and the results revealed that the morphology of the spheres were well kept after the componential and structural transformation from Cu-2(OH)(3)NO3 into CuO. The TGA/DSC study showed that the CuO nano/microspheres could be explored to be a promising additive for accelerating the thermal decomposition of ammonium perchlorate (AP). Combining with the current curve and emission spectrum measured in the plasma electrolysis, formation mechanism of the Cu-2(OH)(3)NO3 spheres was also discussed. (C) 2011 Elsevier Inc. All rights reserved.