Synthesis of ZnO: Cu and Ag Bimetallic Nanoparticles by Laser Ablation

Abstract

Nanoparticles (ZnO: Ag and Cu) were prepared using the pulsed laser ablation method in liquid. The prepared samples were characterized by X-ray diffraction patterns (XRD), particle size analysis (PSA), UV-visible spectroscopy, and Zeta potential (ZP). the JCPDS standard card for Zn (01-080-0074) validated the hexagonal ZnO structure by X-ray diffraction for (ZnO) and (ZnO: Cu and Ag). we calculated the average crystal size of all the produced samples, and we observe that the crystal size grows as the ratio of copper and silver doping rises. The UV-VIS results showed excellent absorption bands of 290–345 nm, confirming that the Ag-containing nanocomposites absorb visible light. As a result, the spectral absorption band of pure ZnO widens with the adding of Cu and Ag, and the absorption edge moves towards a longer wavelength. This significant increase in absorption in the visible region indicates that the generated nanocomposites can reach a more significant catalytic activity in the visible region. The energy gap value decreases, namely 2.97, 2.90, 2.87, 2.79, 2.65, and 2.488 eV, respectively, due to the increasing doping ratio of silver and copper. ZP data of colloidal solutions containing (ZnO) and (ZnO: Ag and Cu) nanoparticles exhibits negative values indicating increased stability of the nanoparticles. However, the ZP data was found to be dependent on the concentration of the surfactant, with an increase in the zeta potentials value corresponding to an increase in the concentration of the surfactant. The PSA results showed promising outcomes and the absence of nanoparticle agglomeration. The synthesized particles were analyzed using FESEM and IMAGE J software to indicate if the particles were nano-sized. Additionally, the particles spherical and quasi-spherical shapes were investigated and found to be of minimal nanoscale size.

Keywords

• Bimetallic nanoparticles, ZnO, Cu, Ag, doping, laser ablation, Energy gap