The size of Cu crystallites in the obtained composites was calculated by Sherrer equation and the values shown in Table are the mean values for sizes, calculated for all reflections (if other is not explicitly stated) . The size of such crystallites according to XRD data varied from 13 nm (Cu@C-1) to 47 nm (Cu@SiO2-19). We assumed, that the size of Cu particles could be influenced by pyrolisis parameters or composition of mixture. Similarly, copper content in the mixture used for pyrolysis showed no relation to particles size. However, samples obtained at different pyrolysis rates contained particles with very different sizes, so this parameter seems to have no relation to the particles size (Fig. ). At the same time, temperature shift from 300 °C to 400 °C and further rise to 600 °C led to bigger particles (Fig. ). It also can be noted that composited prepared from DAB complexes generally gave bigger particles. TEM images of Cu@SiO2-18 and Cu@SiO2-19, which provided the highest product yield, are presented in Figure . Individual dark spherical particles of about 50 nm size can be observed in TEM images. These particles can be assigned to metallic Cu or core-shell particles Cu@C. The size of particles, found by TEM, exceeds the size of Cu crystallites, estimated by powder XRD (33 and 47 nm, Table ), the difference can be explained by the presence of a non-crystalline shell on the surface of the particles. Quite surprisingly, very large Cu partciles were found by SEM in some samples (Fig. ). Cu particles in the form of polyhedra ranging in size from 150 to 400 nm were found on the SEM image of Cu@SiO2-4 (Fig. ) and aggregates of particles of similar size, but elongated shape were found in the case of Cu@SiO2-9 (Fig. ).These images were obtained in back-scattered electron mode (BSE) in order to distinguish copper phase phases on the surface unambiguously, because Cu nanoparticles can be observer as the most bright particles due to larger atomic number compared to Si or C. These data do not agree with the results of powder XRD examination, and probably large part of Cu is desposited as smaller particles. In order to obtain information on the carboneous component, Raman spectra of the composites, which provided the highest product yield, were analyzed . Three Raman peaks could be distinguished in the spectra, which were attributed to the bands D (~1350 cm-1), G (~1580 cm-1)