THE PHOTOCATALYTIC degradation of methylene blue was …….investigated by various types of titanium dioxide particles which include three different nano particle size (28, 65 and 200 nm) as a result of calcinations temperature. Titanium oxides were characterized by scanning electron microscopy (SEM) and X-ray diffraction. The degradation was monitored by measuring the change of dye concentration as a function of irradiation time under UV radiation. The anatase type in nano size, 28 nm and 65 nm has an expected high rate than rutile of titanium which its size equals 5 to 200 nm for photodegradation efficiency, while the commercial titanium grade has degradation rate less than the three calcinated nano sized types.
The effects of UV radiation time and the initial concentration of MB were investigated. The results indicate that the rate of degradation increases as UV radiation time increasing. The kinetics study indicate that the photodegradation of MB by TiO2 behaves as first order reaction.