title: Tm-doped TiO2 and Tm2Ti2O7 pyrochlore nanoparticles: enhancing the photocatalytic activity of rutile with a pyrochlore phase.
abstract: Tm-doped TiO2 nanoparticles were synthesized using a water-controlled hydrolysis reaction. Analysis was performed in order to determine the influence of the dopant concentration and annealing temperature on the phase, crystallinity, and electronic and optical properties of the resulting material. Various characterization techniques were utilized such as X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy and UV-vis spectroscopy. For the samples annealed at 773 and 973 K, anatase phase TiO2 was obtained, predominantly internally doped with Tm(3+). ICP-AES showed that a doping concentration of up to 5.8 atom % was obtained without reducing the crystallinity of the samples. The presence of Tm(3+) was confirmed by X-ray photoelectron spectroscopy and UV-vis spectroscopy: the incorporation of Tm(3+) was confirmed by the generation of new absorption bands that could be assigned to Tm(3+) transitions. Furthermore, when the samples were annealed at 1173 K, a pyrochlore phase (Tm2Ti2O7) mixed with TiO2 was obtained with a predominant rutile phase. The photodegradation of methylene blue showed that this pyrochlore phase enhanced the photocatalytic activity of the rutile phase.
authors.affiliation: Departamento de Química Física, Facultad de Ciencias, Universidad de Cádiz, E-11510 Puerto Real (Cádiz), Spain.
authors.forename: Desiré M
authors.initials: DM
authors.lastname: De Los Santos
authors.affiliation: Departamento de Química Física, Facultad de Ciencias, Universidad de Cádiz, E-11510 Puerto Real (Cádiz), Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Navas
authors.affiliation: Departamento de Química Física, Facultad de Ciencias, Universidad de Cádiz, E-11510 Puerto Real (Cádiz), Spain.
authors.forename: Teresa
authors.initials: T
authors.lastname: Aguilar
authors.affiliation: Departamento de Química Física, Facultad de Ciencias, Universidad de Cádiz, E-11510 Puerto Real (Cádiz), Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Sánchez-Coronilla
authors.affiliation: Departamento de Química Física, Facultad de Ciencias, Universidad de Cádiz, E-11510 Puerto Real (Cádiz), Spain.
authors.forename: Concha
authors.initials: C
authors.lastname: Fernández-Lorenzo
authors.affiliation: Departamento de Química Física, Facultad de Ciencias, Universidad de Cádiz, E-11510 Puerto Real (Cádiz), Spain.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Alcántara
authors.affiliation: Departamento de Ciencias de los Materiales, Ingeniería Metalúrgica y Química Inorgánica, Facultad de Ciencias, Universidad de Cádiz, E-11510 Puerto Real (Cádiz), Spain.
authors.forename: Jose Carlos
authors.initials: JC
authors.lastname: Piñero
authors.affiliation: Departamento de Ciencias de los Materiales, Ingeniería Metalúrgica y Química Inorgánica, Facultad de Ciencias, Universidad de Cádiz, E-11510 Puerto Real (Cádiz), Spain.
authors.forename: Ginesa
authors.initials: G
authors.lastname: Blanco
authors.affiliation: Departamento de Química Física, Facultad de Ciencias, Universidad de Cádiz, E-11510 Puerto Real (Cádiz), Spain.
authors.forename: Joaquín
authors.initials: J
authors.lastname: Martín-Calleja
keywords: nanoparticles; photocatalysis; pyrochlore; thulium; titanium dioxide
references.citation: Chem Commun (Camb). 2010 Apr 7;46(13):2304-6
references.pmid: 20234940
references.citation: J Am Chem Soc. 2010 Sep 1;132(34):11856-7
references.pmid: 20687606
references.citation: Phys Chem Chem Phys. 2013 Sep 21;15(35):14681-8
references.pmid: 23897044