Nano-Copper and Cu/UDD (ultradispersed diamond) nanocomposites were separately prepared by reduction of CuCl2 aqueous solution and that doped with 0.7%(weight percent) of ultra-dispersed diamond. The as prepared nano-crystals were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FTIR) and electron paramagnetic resonance techniques (EPR). It was found that homogeneous nucleation dominated the aqueous reduction reaction at high concentration and the diameter of nano-copper decreased as the reaction time shortened, yet at lower concentration heterogeneous nucleation predominated and the doped UDD functioned as heterogeneous nucleation. Otherwise large number of free-radicals existed in the nano-composites. Both of nano-copper and Cu/UDD nanocomposites were strong catalysts for AP decomposition, with Cu/UDD being a more effective one. The higher decomposition temperature for AP was 119 ℃ lower than that without catalyst. And the exothermic quantity of decomposition was from 590 J·g-1 to 1 400 J·g-1 by mix 2% of the Cu/UDD nanocomposites.
