TITANIUM OXIDE DISPERSED ON NATURAL ZEOLITE (TiO2/ZEOLITE) AND ITS APPLICATION FOR CONGO RED PHOTODEGRADATION

Abstract

The utilization of TiO₂ dispersed on natural zeolite (TiO₂/Zeolite) for degradation of Congo Red photocatlytically has been performed. The TiO₂/Zeolite was prepared by mechanically mixing of 100 g of natural zeolite, which it has been heated at 400^oC, with TiO₂ powder, the final weight ratio of the mixture was 5% (w/w). The mixture was then calcined at 400^oC for 6 hours. The calcined product was characterized using x-ray diffractometry, x-ray fluorescence analysis and gas sorption analysis methods to determine its physicochemical properties changes caused by mixing and calcination. Investigation of Congo Red photodegradation using TiO₂/Zeolite was carried out by mixing 25 mL 10^-4 M solution of Congo Red with 25 mg of TiO₂/Zeolite and irradiating the suspention with UV-light of 350 nm for 10, 20, 30, 40, 50 and 60 minutes, respectively. The characterization results showed that dispertion of TiO₂ on zeolite resulted in the increasing of titanium concentration on TiO₂/Zeolite. The concentration of Ti on natural zeolite was found to be 0.15%(w/w), meanwhile on TiO₂/Zeolite was 2.29% (w/w). From X-ray diffractometry analysis result no information was found that TiO₂ was dipersed on natural zeolite. It was caused by overlapping of the reflections of zeolite with reflections of TiO₂. On the otherhand, the gas sorption analysis result exhibited that the dispersion of TiO₂ on zeolite resulted in the decreasing of total pore volume as well as specific surface area of the natural zeolite. The specific surface areas of natural zeolite and TiO₂/Zeolite were 21.98 and 16.74 m²/g, respectively, meanwhile the total pore volumes of natural zeolite and TiO₂/Zeolite were 20.10x10^-3 and 13.47x10^-3 mL/g. The simple kinetic of photodegradation of Congo Red exhibited that the rate of degradation followed a first order kinetic and the reaction rate constant was 0.0017 minute^-1.