title: Solar photocatalytic degradation of isoproturon over TiO2/H-MOR composite systems.
abstract: The photocatalytic degradation and mineralization of isoproturon herbicide was investigated in aqueous solution containing TiO2 over H-mordenite (H-MOR) photocatalysts under solar light. The catalysts are characterized by X-ray diffraction (XRD), UV-Vis diffused reflectance spectra (UV-Vis DRS), Fourier transform-infra red spectra (FT-IR) and scanning electron microscopy (SEM) techniques. The effect of TiO2, H-MOR support and different wt% of TiO2 over the support on the photocatalytic degradation and influence of parameters such as TiO2 loading, catalyst amount, pH and initial concentration of isoproturon on degradation are evaluated. 15wt% TiO2/H-MOR composite is found to be optimum. The degradation reaction follows pseudo-first order kinetics and is discussed in terms of Langmuir-Hinshelwood (L-H) kinetic model. The extent of isoproturon mineralization studied with chemical oxygen demand (COD) and total organic carbon (TOC) measurements and approximately 80% mineralization occurred in 5h. A plausible mechanism is proposed based on the intermediates identified by liquid chromatography-mass spectroscopy (LC-MS).
authors.affiliation: Inorganic and Physical Chemistry Division, Indian Institute of Chemical Technology, Hyderabad 500607, India.
authors.forename: Mangalampalli V Phanikrishna
authors.initials: MV
authors.lastname: Sharma
authors.forename: Valluri
authors.initials: V
authors.lastname: Durgakumari
authors.forename: Machiraju
authors.initials: M
authors.lastname: Subrahmanyam
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry*; D002384:Catalysis; D002851:Chromatography, High Pressure Liquid; D003247:Conservation of Natural Resources; D006540:Herbicides / Q000737:chemistry* / Q000528:radiation effects; D013058:Mass Spectrometry; D008855:Microscopy, Electron, Scanning; D010100:Oxygen / Q000032:analysis; D010671:Phenylurea Compounds / Q000737:chemistry* / Q000528:radiation effects; D010777:Photochemistry; D012993:Solar Energy; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D014025:Titanium / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D000538:Aluminum Silicates; D006540:Herbicides; D010671:Phenylurea Compounds; C048397:mordenite; C009495:titanium dioxide; C028904:isoproturon; D014025:Titanium; D010100:Oxygen