Effect of Thermal Treatment on the Phase Composition and Surface Properties of WO3‐TiO2 Nanocomposites Synthesized via Hydro‐Thermal Method

Abstract

AbstractThere is a huge interest in the synthesis of nanocomposites with specific physicochemical properties. Calcination temperature affects the size, morphology and other surface characteristics. WO3‐TiO2 nanocomposites were synthesized by hydrothermal method using titanium (IV) butoxide and tungsten (VI) oxide (WO3). The effects of drying time and calcination temperature on the hydrodynamic particle diameter, crystallite size, shape and zeta potential of the nanocomposites was investigated. The samples were dried in oven at 80 °C for 18 hours, calcinated at 300 to 1000 °C and analyzed by X‐ray diffraction (XRD), field emission scanning electron microscope (FE‐SEM) and fourier‐transform infrared spectroscopy (FTIR). Hydrodynamic diameter and zeta potential were measured by particle analyzer (DLS). The mean crystallite size increased from 25.2 nm to 54.9 nm when calcination temperature increased from 300 to 1000 °C. Hydrodynamic size of the nanocomposite decreased with increasing drying time, became constant after 12 hours of drying and did not change significantly after that. Moreover, the hydrodynamic size increased with increase in the calcination temperature due to growth of the crystals and formation of inter particle necks. The large zeta values (−35.8 to −41.2 mV) suggest that the nanocomposites show large electrostatic repulsive interaction and enhanced stability in aqueous solutions.