title: Photocatalytic degradation of paraquat using nano-sized Cu-TiO2/SBA-15 under UV and visible light.
abstract: Photocatalytic degradation of paraquat using mesoporous-assembled Cu-TiO2/SBA15 under UV and visible light was investigated. The catalyst was synthesized by impregnation of Cu-TiO2 colloids onto SBA-15. The colloids of Cu-TiO2 were prepared via sol-gel method while the mesoporous support was prepared using hydrothermal technique. The catalyst was characterized using X-ray diffraction, nitrogen adsorption-desorption, transmission electron microscopy, UV diffuse reflectance spectroscopy, Zeta potential and X-ray adsorption spectroscopy. Results from characterizations showed that Cu doped TiO2 had a small crystalline size and was well-dispersed on SBA-15. The inclusion of SBA-15 significantly enhanced the photocatalytic activity of the catalyst. Among the three types of undoped catalyst in this study (P25, TiO2, TiO2/SBA-15), TiO2/SBA-15 yielded the highest degradation of paraquat for all pH under UV illumination. Meanwhile 2 wt.% Cu-TiO2/SBA-15 yielded the highest activity under visible light.
authors.affiliation: Department of Chemical Engineering, College of Engineering, University of the Philippines, Diliman 1101, Quezon City, Philippines. mauricesorolla@yahoo.com
authors.forename: Maurice G
authors.initials: MG
authors.lastname: Sorolla
authors.forename: Maria Lourdes
authors.initials: ML
authors.lastname: Dalida
authors.forename: Pongtanawat
authors.initials: P
authors.lastname: Khemthong
authors.forename: Nurak
authors.initials: N
authors.lastname: Grisdanurak
mesh_terms: D002384:Catalysis; D003300:Copper / Q000737:chemistry* / Q000528:radiation effects; D006540:Herbicides / Q000737:chemistry* / Q000528:radiation effects; D006863:Hydrogen-Ion Concentration; D008027:Light; D053758:Nanoparticles / Q000737:chemistry / Q000528:radiation effects; D010269:Paraquat / Q000737:chemistry* / Q000528:radiation effects; D010782:Photolysis; D012822:Silicon Dioxide / Q000737:chemistry* / Q000528:radiation effects; D014025:Titanium / Q000737:chemistry* / Q000528:radiation effects; D014466:Ultraviolet Rays; D014874:Water Pollutants, Chemical / Q000737:chemistry* / Q000528:radiation effects; D018508:Water Purification / Q000379:methods
chemical_list: D006540:Herbicides; C509969:SBA-15; D014874:Water Pollutants, Chemical; C009495:titanium dioxide; D012822:Silicon Dioxide; D003300:Copper; D014025:Titanium; D010269:Paraquat