title: Delaminated montmorillonite with iron(III)-TiO₂ species as a photocatalyst for removal of a textile azo-dye from aqueous solution.
abstract: A set of mesoporous delaminated montmorillonites containing iron(III)-titanium oxide species was synthesized using two minerals: a bentonite as support and an ilmenite as source of Fe-TiO2 species. Several values of both sulphuric acid concentration and temperature were employed to extract Fe-TiO2 species from an ilmenite. Analyses by X-ray fluorescence, X-ray diffraction, scanning electron microscopy and nitrogen adsorption-desorption confirmed the successful formation of delaminated (or exfoliated) mesoporous structures. Optical properties of solids were determined by UV-Vis diffuse reflectance spectroscopy, and their band gap energy values were also calculated. A small UV-shift of band gap values regarding that of commercial photo-active TiO2 was detected as consequence of the quantum size effect, suggesting that photocatalytic experiments should be performed under UV-radiation assistance. The synthesized solids showed good activity in the photocatalytic oxidation of a textile dye (reactive yellow 145: RY 145), achieving conversions higher than 70% and chemical oxygen demand removal between 60% and 80%.
authors.affiliation: a Estado Sólido y Catálisis Ambiental (ESCA), Departamento de Química, Facultad de Ciencias , Universidad Nacional de Colombia , Bogotá , Colombia.
authors.forename: Juan A
authors.initials: JA
authors.lastname: Torres-Luna
authors.affiliation: a Estado Sólido y Catálisis Ambiental (ESCA), Departamento de Química, Facultad de Ciencias , Universidad Nacional de Colombia , Bogotá , Colombia.
authors.forename: José G
authors.initials: JG
authors.lastname: Carriazo
authors.affiliation: a Estado Sólido y Catálisis Ambiental (ESCA), Departamento de Química, Facultad de Ciencias , Universidad Nacional de Colombia , Bogotá , Colombia.
authors.forename: Nancy R
authors.initials: NR
authors.lastname: Sanabria
mesh_terms: D000327:Adsorption; D001391:Azo Compounds / Q000302:isolation & purification*; D001546:Bentonite / Q000737:chemistry*; D002384:Catalysis; D004396:Coloring Agents / Q000302:isolation & purification*; D005290:Ferric Compounds / Q000737:chemistry; D007501:Iron / Q000737:chemistry*; D010083:Oxidants, Photochemical / Q000737:chemistry*; D013784:Textiles / Q000032:analysis; D014025:Titanium / Q000737:chemistry*; D014466:Ultraviolet Rays; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents; D005290:Ferric Compounds; D010083:Oxidants, Photochemical; D014874:Water Pollutants, Chemical; C029232:ilmenite; D001546:Bentonite; C009495:titanium dioxide; D014025:Titanium; D007501:Iron
keywords: Delaminated clay; ilmenite; reactive yellow 145; textile dye; titanium dioxide