Aerosol-assisted low-temperature processing of colloidal TiO2 nanoparticles: two different manners for improving the optical properties

Abstract

In order to preserve unique properties of TiO2 nanoparticles towards their surface modification, two different approaches of low temperature aerosol-assisted processing were performed. Both were based on colloid precursor atomization and subsequent spray drying at T=150 oC in a hot wall reactor. In the first case, pure TiO2 colloid precursor solution was atomized and produced submicronic particles are subsequently modified, while in the second one atomization of already modified colloid precursor solution were done. In both cases the TiO2 surface modification was achieved with 30 % of dopamine. Powders crystallinity and phase composition were studied by X-ray powder difraction (XRPD), while detailed powders morphological characterization was followed using scanning and transmission electron microscopy (SEM and TEM). Optical properties of the surface modified TiO2 particles were investigated using reflection spectroscopy while the binding structure between dopamine and the surface titanium atoms was investigated by FTIR spectroscopy.