Abstract
Sensitized kaolinite with improved visible-light catalytic activity was prepared via a facile in-situ growth of nanosized Cu-TiO(2)on the surface of the sulfated kaolinite impregnated in Cu-TiO(2)sol. The as-prepared photocatalysts were characterized in terms of various techniques. The transmission electron microscope and energy dispersive spectrometer results revealed that Cu-TiO(2)could grow on the surface of the pretreated kaolinite and the aggregation of Cu-TiO(2)was successfully inhibited. The X-ray photoelectron spectrum confirmed the formation of Al-O-Ti bonds between Cu-TiO(2)and sulfated kaolinite in the sensitized kaolinite composite. The sensitized kaolinite composite exhibited significantly improved performance in the degradation of Rhodamine B (RhB), leading to about 87% of RhB degradation in 180 min, which is superior to that of the kaolinite, calcined kaolin, and sulfated calcined kaolin under visible-light irradiation. The superior photodegradation activity of the sensitized kaolinite composite was primarily attributed to the synergetic effect of Cu-TiO(2)sensitization and sulfation, resulting from the efficient transfer and separation of the photo-induced charge carriers between Cu-TiO(2)and kaolinite.