Background: Carbon-coated metal nanoparticle is a kind of unique nuclear-shell material
that is the carbon shell filled with metal particles. It has a great promising future in the application as
excellent solid lubricants additives, conducting resin, antiradiation material and so on. As a mature
technology, the gas detonation method has been widely used to synthesize various nanomaterials.
Method: Using copper acetylacetonate as a precursor to provide carbon and different concentrations
of argon as a protective medium for the first time, high quality carbon-coated copper nanoparticles
(Cu@C) were synthesized in hydrogen and oxygen. X-ray Diffraction (XRD), Raman spectroscopy
and transmission electron microscopy (TEM) were employed to characterize the structure, phase and
constituent of the Cu@C nanoparticles to investigate the influence of argon concentration on the
Results: The XRD pattern, Raman spectroscopy and TEM images confirm the effect of Ar on synthesizing
Cu@C, especially on particle size. The minimum average size is around 13 nm, and most
of the particle size distribution is in 5-10 nm range. When the argon concentration is high, the detonation
process of H2 and O2 will be suppressed, which is not conducive to the graphitization.
Conclusion: Argon gas has a catalytic effect on the synthesis of high-quality Cu@C, which could
significantly reduce the particle size of detonation products; the grain size appears an obvious downtrend
with the concentration of argon increasing, but the high concentration of Ar is disadvantageous
for the graphitization of carbon shells.