Anatase-TiO2 nano-particle preparation with a micro-mixing technique and its photocatalytic performance

A micro-mixing method named membrane dispersion precipitation technology has been developed, and used to prepare titanium oxide nano-particles in this work. Titanium sulfate and ammonia bicarbonate were selected as reactants. The microcrystal structure of the TiO2 was characterized by an X-ray diffractometer, and morphology by a transmission electron microscopy (TEM). In addition, the photocatalytic performance of these TiO2 ultra-fine particles were evaluated by the methylic orange photocatalytic degradation. The experimental results showed that the particles were anatase and amorphous phase, the average diameters were in range of 10-20 nm. The particles have excellent photocatalytic efficiencies, and more than 90% methylic orange was degraded in an hour. The kinetic behavior of photocatalysis belongs to zero order. It is found that the reaction constant is directly proportional to the diameter of particles, by investigating the influence of the particle size on the photocatalysis. (C) 2004 Elsevier B.V. All rights reserved.