Preparation of zinc oxide/silica nanocomposite particles via consecutive sol–gel and flame-assisted spray-drying methods

• Water glass was used as a silica source to prepare ZnO/SiO2 nanocomposite.
• The mixed ZnO–SiO2 colloids were dried by flame-assisted spray-drying methods.
• The addition of SiO2 to ZnO resulted in the increase of the particles photoluminescence intensity.
• Silica content of the nanocomposites is significantly affected the particles characteristics.

ZnO/SiO2 nanocomposites were prepared using consecutive sol–gel and flame-assisted spray-drying methods. Zinc oxide and silica sols were prepared individually from zinc acetate and water glass, respectively, via a sol–gel method. Subsequently, zinc oxide sol, silica sol, and a mixture of both were spray dried in a flame reactor to generate powder of pure zinc oxide, pure silica, and a ZnO/SiO2 nanocomposite, respectively, in order to compare the characteristics. The generated particles were characterized via luminescence spectrophotometer, Fourier Transform Infrared (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) to obtain the photoluminescence spectra, chemical bonding, crystallinity, and morphology of the particles, respectively. The photoluminescence emission recorded at 250 nm excitation showed a peak at approximately 400 nm that was characterized by a violet band. The highest intensity was shown by a 75 mol% ZnO sample followed, in order, by 50 mol% ZnO, 25 mol% ZnO, and pure ZnO.