Ultrasonochemical coating and characterization of TiO2-coated zirconia fine particles

Zirconia fine particles were prepared by ultrasonic spray pyrolysis (USP) and employed as a substrate for titanium/titania coating by ultrasonochemistry. The effects of several process factors on the characteristics of the prepared particles were investigated and the particles were then characterized by various techniques. This substrate was coated with various titanium concentrations (0.025–0.1 M) for two ultrasonication time periods (30 min, 2 h) by sonochemistry, and finally calcined at 1100 °C. Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), particle size analysis (PSA), Fourier transformation infrared spectroscopy (FT-IR) and inductively coupled plasma-atomic emission spectroscopy (ICP-AES) comprised the techniques used to characterize them. The particles were prepared in a monodispersed spherical form with no interior cavity; their average size was shown to be 0.62 μm before calcination and 2.57 μm after calcination. The titania surface coating acted to partially stabilize the particles to a tetragonal phase. Based on the analytical results, the optimum conditions for preparing the particles were shown to be 7.5 wt% of titania as an initial solution concentration and 0.5 h of coating time.