Date of Publication : 13, Aug, 2019
Author: 1Aroh, A.O.,
Co Author: 1Gimba, C.E.,1Omoniyi, K.I., 1Abba, H. and 2Yilleng, M.T.,
Photocatalytic degradation of 4-cahlorophenol and 3-chlorophenol was studied using Ag and Pd doped on P25 Degussa TiO2. The Ag/ TiO2 and Pd/ TiO2 photocatalysts were prepared by sol immobilization method. The prepared photocatalysts were used in photocatalytic degradation of 4-chlorophenol and 3-chlorophenol respectively and monitored using HPLC. The resulting solution from the photocatalytic degradation of 4-chlorophenol and 3-chlorophenol were filtered and the catalyst washed and dried. The dried catalysts were subsequently used again under the same experimental condition with a fresh 4-chlorophenol and 3-chlorophenol respectively. The re-usability curve of the 4-chlorophenol and 3-chlorophenol photodegradation using 0.5% Pd/ TiO2 and 0.5% Ag/ TiO2 were obtained. The comparison of the result obtained indicates that pd/TiO2 has a photodegradation efficiency of 78.44% within 120 minutes’ irradiation while Ag- TiO2 has a photodegradation efficiency of 82.44%. The result indicates that the photodegradation of 4-chlorophenol is smoother than 3-chlorophenol because of inductive and mesomeric effect on ortho-para and meta-position. The re-usability curve indicates that the 0.5% Pd/ TiO2 and Ag/ TiO2 used for 4 times in photo-degradation gives reduction in concentration of chlorophenol except for the fourth usage which is attributed to catalyst leaching. The calculation of rate constant indicates that the photo-degradation of 4-chlorophenol and 3-chloropnehol follows pseudo-first order reaction kinetics. These indicate that the use of dopants increases the photocatalytic efficiency titanium dioxide.
Keywords : 4-chlorophenol, 3-chlorophenol, degradation, kinetics, Ag/Pd-dopant, photocatalysis, inductive and mesomeric effect, photodegradation,