Investigation of the structure and dispersion of photoactive nanocrystal TiO2 powders

Effect of the pH in the synthesis of ammonium titanate gel and the temperature of xerogel dehydration on the phase composition, degree of crystallinity, and dispersion of photoactive TiO2 powders is investigated. The possibility of preparing a metastable anatase modification of TiO2 with high crystallinity is shown. The textural, adsorption, and photocatalytic characteristics of the obtained dispersions are studied. Using atomic force microscopy (AFM) and spectral turbidimetry, the presence of particle aggregates and intergrowns causing the TiO2 coloring by organic dyes in the aqueous dispersions of photocatalysts is found.