Exploiting Cu⁺-Na⁺ ion-exchanged and Ar/H₂ annealed glass matrix to synthesize copper nanoparticles

Copper nanoparticles (CuNPs) were successfully prepared in Cu+-Na+ ion-exchanged commercially available silicate glasses followed by being annealed in Ar/H-2 atmosphere; in an approach that can be quite economic capable of modifying the physicochemical properties of glass. This approach resulted in the growth of spherical and crystalline CuNPs, with an average size of 67.5 nm, which is greater than the CuNPs average size obtained with annealing at air atmosphere (15.8 nm). On the treated glasses, phase transitions indicative of a shape memory effect and dendritic structures were also detected, indicating their vital roles, as crystal growth mechanisms in the resultant CuNPs. The surface plasmon peaks of CuNPs have been clearly observed in absorption spectra of doped annealed glasses at 350, 450, and 550 degrees C in Ar/H-2. Photoluminescence studies have proved the presence of both Cu+ and Cu2O. The detailed methodology and the structural and morphological characterizations of the annealed copper ion-exchanged samples were carried out using optical microscopy (OM), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy and high-resolution TEM (TEM and HRTEM), and their reasoning are thoroughly described and discussed.