The effect of the composition of tri-elemental doping (K, Al, S) on the photocatalytic performance of synthesized TiO2 nanoparticles in oxidizing 2-chlorophenol over visible light illumination

摘要

This study investigated the effect of tri-elemental doping specifically potasium (K), aluminum (Al) and sulfur (S) on the performance of the synthesized titanium dioxide (TiO_2) nanoparticles under visible light illumination. The synthesized photocatalyst was prepared by sol-gel method using potash alum or potassium aluminun sulfate [KAl(SO4)2] as dopant. The process involves hydrolysis and condensation reactions of titanium alkoxides forming oxo-polymers. The process involved oxidation of 2-chlorophenol (2-CP) in aqueous conditions. The specific surface area, morphology, structure and surface charge of the synthesized photocatalyst were comparable to those of commercial Degussa P-25. Results show that the specific surface area of the catalysts decreased after calcination process. This effect corresponds with the XRD results, surface charge, EDS and photo-oxidation of the 2-CP using the TiO2/KA1(SO4)2 catalyst, wherein oxidation of 2-CP can be increased up to 96% in 4 h irradiation. However, complete mineralization of 2-CP needs longer irradiation time.