Pure and Cu-Doped ZnO Nanoparticles: Hydrothermal Synthesis, Structural, and Optical Properties

Abstract

Pure and Cu-doped zinc oxide (Zn1 –xCuxO with x = 0.00, 0.05, 0.10, and 0.15) nanoparticles were prepared via hydrothermal synthesis using a solution of zinc sulfate (ZnSO4) as precursor, p-phenylenediamine as structure-directing agent in the presence of different amounts of CuSO4 and NaOH. XRD, Raman, UV–Vis, and PL techniques were used to characterize the as-synthesized samples. The XRD analysis reveals that the average particle size of pure ZnO is 13.50 nm. It decreased to 12.11 nm for the Cu-doped sample Zn0.95Cu0.05O, then to 11.00 nm when x = 0.15 (Zn0.85Cu0.15O). The optical band gap of pure and Cu-doped ZnO nanoparticles was calculated from UV–Vis spectra. It turned out to have decreased from 3.18 to 3.11 eV as the amount of Cu increases up from x = 0 to 0.15. The photoluminescence study shows that the introduction of Cu into pure ZnO causes a decrease in surface defects, such as oxygen vacancy and zinc vacancy.