Kinetic Mechanism of Photo-catalytic Oxidation for Soluble Methylene Blue by Iron-doped TiO2

Nano-TiO₂ photo catalyst powders were prepared through the sol-gel method and with supercritical fluid drying (SCFD). The SEM, XRD and particle size distribution technique were used to characterize the hyperfine TiO₂ particles. The reaction of photo-catalysis for methylene blue is in conformity with the first order kinetic law in appearance within the concentration range between 5mg/L and 15 mg/L. As the initial concentration methylene blue in water increase, the appearance rate constant of the reaction decreases while the half-life period of the reaction increases.