Silver and copper nanoparticles: Lower concentration controlled thermal decomposition of their salt precursors

Generally, salt precursors have been investigated for the production of nanoparticles with semiconducting properties such as metal chalcogenides and others. They have demonstrated excellent features for the ease of converting them to nanoparticles. Thermal decomposition and solvothermal processes are often followed to produce particles with stabilizers of varied ranges of size with improved size control dependent on the set collective conditions and the intended applications. In this study, silver (Ag) and copper (Cu) nanoparticles were synthesized using the thermal decomposition method in the presence of oleylamine as a capping agent in order to produce good stable uniform monodispersed nanoparticles. Lower amounts of Ag and Cu precursors (0.1 - 0.2 g) were used to study their effect on the size and morphology of the nanoparticles. The synthesized nanoparticles under various conditions were characterized using UV/Vis and PL spectroscopy, TEM, and XRD. It was observed that an increase in the precursor concentration led to an increase in particle size with varying morphologies for both Ag and Cu nanoparticles. The TEM images of Ag nanoparticles showed that uniform morphology and spherical shape were observed with narrow diameters ranging from 5.9 to 6.8 nm. However, for Cu nanoparticles, uniform morphology and spherical shape were only observed at a precursor concentration of 0.15 g with an average diameter of 7.8 nm. The XRD results of both Ag and Cu nanoparticles showed peaks that were identified as Ag and Cu in the face-centred cubic.