PHOTOCATALYTIC DEGRADATION OF ORGANIC POLLUTANTS WITH PT-CaFe2O4/TiO2 COMPOSITE UNDER VISIBLE-LIGHT IRRADIATION

In this study, visible-light active photocatalyst based on TiO2 was designed using CaFe2O4 nanoparticle as an effective sensitizer. CaFe2O4 nanoparticles (CFO) were synthesized by Pechini method using calcium nitrate and iron nitrate. Then, the high crystalline CFO calcined at 800 degrees C was combined with TiO2 in a simple sol-gel aging. In order to form coupled structure, CFO suspension and TiO2-precursor solution were mixed in ethanol solution, and then heated at 80 degrees C while vigorously stirring. After 6 hrs, the coupled particles were filtered and dried, followed by calcination at 400 degrees C. The prepared composites were tested for photocatalytic oxidation of Salicylic acid, a model organic compound under visible-light (lambda >= 420 nm) as monitored by UV-Visible Spectrophotometer. The origin of photoactivity of the heterojunction was found mainly due to the superoxide radical and generation of hydroxyl radical was negligible. The average photo-conversion performance was obtained because of unique energy band matching between CFO and TiO2.