Rapid synthesis, characterization and optical properties of TiO2 coated ZnO nanocomposite particles by a novel microwave irradiation method

Abstract A novel and rapid microwave method was used to prepare TiO 2 coated ZnO nanocomposite particles. The resulted particles were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HR-TEM) and X-ray photoelectron spectroscopy (XPS). Results show that ZnO nanoparticles were coated with 6–10 nm amorphous TiO 2 layers. In addition, zeta potential analysis demonstrated the presence of TiO 2 layer on the surface of ZnO nanoparticles. Photoluminescence (PL) spectroscopy and UV–visible spectroscopy were used to investigate the optical properties of the nanoparticles. Compared to uncoated ZnO nanoparticles, the TiO 2 coated ZnO nanoparticles showed enhanced UV emission. The UV–visible diffuse reflectance study revealed the significant UV shielding characteristics of the nanocomposite particles. Moreover, amorphous TiO 2 coating effectively reduced the photocatalytic activity of ZnO nanoparticles as evidenced by the photodegradation of Orange G with uncoated and TiO 2 coated ZnO nanoparticles under UV radiation.