Sonochemical Synthesis and Characterization of Ag/ZnO Heterostructure Nanocomposites and their Photocatalytic Efficiencies

Ag/ZnO heterostructure nanocomposites containing different amounts of Ag were successfully synthesized in surfactant-free solutions by a sonochemical deposition. The samples were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), x-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectroscopy and Raman spectroscopy. The results show that all heterostructure samples were composed of metallic Ag nanoparticles supported on top of nanoplate petals of hierarchical ZnO flowers. The photocatalytic properties of the samples were also evaluated through photodegradation of methylene blue (MB) and methyl orange (MO) as cationic and anionic model dyes under UV light irradiation. The photodegradation of MB and MO solutions containing Ag/ZnO heterostructure nanocomposites was higher than that of MB and MO solutions containing pure ZnO flowers because of the efficient separation and diffusion of photogenerated charge carriers through Ag/ZnO Schottky interface. Active species for MB and MO photodegradation were also investigated in this research. Graphical Abstract