TiO2-Assisted Photodegradation of Direct Blue 78 in Aqueous Solution in Sunlight

The photodegradation of azo dyes aqueous solution has been investigated using TiO2 as catalyst in sunlight. The effect of amount of catalyst, concentration of dye, and pH value on the degradation of Direct Blue 78 was observed. A complete degradation of 100 mg/L Direct Blue 78 solution under solar irradiation was achieved in 6 h at pH 3.0, dosage of TiO2 1.0 g/L. A possible pathway for the photodegradation of Direct Blue 78 in sunlight was proposed.