PHOTOCATALYTIC DEGRADATION OF PHENOL IN AQUEOUS SOLUTION USING Fe/TiO2 THIN FILMS UNDER UV AND VISIBLE LIGHT. by ANIS MANSOR

Photocatalytic degradation of phenol by oxidation, utilizing doped TiO2 (Fe/TiO2) as photocatalyst in the form of immobilized thin films in a jacketed photocatalytic batch reactor was the subject of this research. Fe/TiO2 photocatalyst was successfully synthesized using sol-gel method and coated on the chosen glass substrates using the wet coating method of dip-coating. Titanium isopropoxide was used as the titanium precursor, isopropanol as the solvent and diethanolamine (DEA) as the stabilizing agent. The addition of transition metal ion, Fe was utilized as the dopant for the preparation of TiO2 thin films. The purpose of adding this dopant is to initiate the red shift in the absorbance spectrum of TiO2 photocatalyst for usage in visible light. The characteristics of the coated thin films were determined by XRD patterns, showing anatase and rutile crystalline phases. Fe crystalline phase was also detected at 2θ = 48.1 ̊. SEM images showed that the surface of the supports was completely covered with thin film with good adhesion. EDX spectrum for Fe/TiO2 films detected the existence of titanium and iron (Fe) within the films. In this research, the performance of the synthesized TiO2 was studied for the degradation of phenol in a photocatalytic reactor. The optimum values for the studied process variables were; initial phenol concentration of 50 ppm, Fe/TiO2 catalyst loading of 3 layers, solution pH at pH 3 and H2O2 concentration of 300 ppm. For the study on the effect of wavelength, Fe/TiO2 showed the highest activity in UV light, able to degrade 87.3 % phenol in 6 hours. It successfully degraded 37.0 % phenol even under visible light irradiation. The widely accepted Langmuir-Hinshelwood kinetic model was used for the reaction kinetics in this study. The degradation of phenol in this study was found to fit the first order kinetics. The obtained rate constant was k = 0.325 ppm/min while the adsorption constant was