Influence of aggregate size on photoactivity of N-doped TiO2 particles in aqueous suspensions under visible light irradiation

摘要

This work is focused on the study of the correlation between the photocatalytic activity of N-doped TiO2 particles, achieved by a designed synthesis, and their degree of aggregation in aqueous suspension. N-doped TiO2 photocatalyst particles, suspended in bidistilled water, presented a trimodal (in the nano-micro metric range) aggregate size distribution. This distribution resulted monomodal, in the nanometric range, when in the aqueous solution was added an organic dispersing agent (azulene). This behavior was associated to the presence, on the N-doped TiO2 particle surfaces, of an organic phase which was detected by thermal and infrared analysis. This organic phase was assumed to have a stabilizing function for nanoparticles.