Significant effect of ph on photocatalytic degradation of organic pollutants using semiconductor catalysts

• Main Authors: Jaafar, N. F., Jalil, A. A., Triwahyono, S., Ripin, A., Ali, M. W.
• Format: Article
• Language: English
• Published: Penerbit UTM Press 2016
• Subjects: QD Chemistry
• Online Access: http://eprints.utm.my/id/eprint/74320/1/NurFarhanaJaafar2016_SignificantEffectofPhonPhotocatalytic.pdf; http://eprints.utm.my/id/eprint/74320/; https://www.scopus.com/inward/record.uri?eid=2-s2.0-84988344339&partnerID=40&md5=4dc5614d9377120bb307b59b6a7ee1b9
• Institution: Universiti Teknologi Malaysia

Photocatalytic is one of the inexpensive and non-toxic techniques for degradation of organic pollutants into harmless substances such as water and carbon dioxide. In this study, simple electrolysis method was used in preparation of Ag/TiO2 and α-Fe2O3/HY catalysts. The physicochemical properties of the catalysts were studied using XRD, FTIR, FESEM-EDX and surface area analysis. The pH of solution plays an important role in the photocatalytic degradation of organic pollutants which influences the surface-charge properties of the catalysts. Ag/TiO2 and α-Fe2O3/HY were used as catalyst on degradation of 2-chlorophenol (2-CP) and methyl orange (MO), respectively. The effect of pH on degradation of 2-CP and MO were investigated over a pH range from 2 to 9. Higher degradation of 2-CP and MO were obtained at pH 5 (74%) and pH 2 (80%), respectively. This finding might be explained by the amphoteric performance of the catalyst using point zero charge (pHZPC). The pHZPC for Ag/TiO2 and α-Fe2O3/HY was found to be at pH 6.3 and pH 7.2, respectively. Hence, the activities of the catalysts may have been affected by the existence of a strong electrostatic field between the positively charged catalysts surface and negatively charged 2-CP and MO caused a pH value lower than their pHZPC give greater degradation.