Self-organized sol-gel TiO2 structures: Particles, rectangle tubes, and flower-like slabs

Abstract

Effects of alcohols on the growth and morphology of TiO2 from two different self-organization methods, i.e., water-vapor hydrolysis and ultraslow water-diffusion hydrolysis, were investigated. In the first method, Ti alkoxide was hydrolyzed by water vapor to generate TiO2 particles in a solution, which exhibited that the alcohols not only reduced the anatase crystal size, but also influenced the packing density of secondary particles and the subsequent sintering outcome, which are attributable to involvement of the alcohols in both self-organization and crystallization processes. In the other method based on the ultra-slow water-diffusion hydrolysis, ethanol led to very compact spherical secondary particles that resulted in a lower sintering temperature, while methanol caused the anisotropic growth of particles that produced two novel 1D structures, i.e., rectangle tubes and flower-like slabs due to incorporation of a structurally different alcohol in the sol-gel process.