Enhanced visible light photocatalytic activity of TiO2 co-doped with Fe, Co, and S for degradation of Cango red.

The photocatalytic activity of TiO2 was enhanced under visible light when it was co-doped with Fe, Co, and S through the sol-gel method. The resultant nano photocatalysts were characterized by XRD, EDX coupled with SEM, FT-IR, UV-Vis, and UV-DRS. The concentration ratio of precursor salts of Fe and S was kept at 1% each and of Co varied between 0.5% -1.5%. The photodegradation of Congo red was carried out and various factors like the concentration of catalyst, initial concentration of dye, pH, and irradiation time were also investigated to optimize the degradation process. Under optimized degradation conditions, 99.3% of Congo red (30 ppm) was degraded at slightly acidic pH, with 0.14 g of photocatalyst within 70 min of irradiation time.