Influence of zirconium doped titanium oxide towards photocatalytic activity of paraquat

Abstract

The heterogeneous photocatalyst based on titanium dioxide has been widely investigated as an attractive treatment method for water pollution. Herbicide like paraquat dichloride is one of the toxic organic pollutants which is harmful to human and animal and is still being used in agricultural sectors. TiO2 doped with zirconium element has been proven to enhance the photocatalytic activity of TiO2 from the previous study. Therefore in this study, photodegradation of paraquat dichloride (1,1-dimethyl-4,4’-bipyridylium dichloride) under UV irradiation was studied using TiO2 and Zr doped TiO2 prepared via modified sol gel method as photocatalysts. The photocatalytic activity was increased in the presence of zirconium as dopant compared to TiO2. Various calcination temperatures range from 450°C to 1000°C and dopant ratio (10:90, 20:80 and 30:70) were applied to optimize the working condition. Significant enhancement was obtained using Zr doped TiO2 (20:80) calcined at 750°C which gave 79.63% degradation of paraquat compared to TiO2 calcined at 450°C and 750°C which were 22.31% and 11.57%. X-ray diffraction (XRD) diffratogram of Zr doped TiO2 photocatalyst showed a mixture of anatase/rutile TiO2 crystalline structures at 750°C. Nanosized photocatalyst with spherical morphology was observed by Field Emission Scanning Electron Microscopy (FESEM). The surface area measured by nitrogen adsorption analysis showed an increment from 8.43m2/g to 46.35m2/g compared to undoped catalyst calcined at 450°C.