title: Combining top-down and bottom-up routes for fabrication of mesoporous titania films containing ceria nanoparticles for free radical scavenging.
abstract: Nanocomposite thin films formed by mesoporous titania layers loaded with ceria nanoparticles have been obtained by combining bottom-up self-assembly synthesis of a titania matrix with top-down hard X-ray lithography of nanocrystalline cerium oxide. At first the titania mesopores have been impregnated with the ceria precursor solution and then exposed to hard X-rays, which triggered the formation of crystalline cerium oxides within the pores inducing the in situ growth of nanoparticles with average size of 4 nm. It has been observed that the type of coordinating agent in the solution plays a primary role in the formation of nanoparticles. Different patterns have been also produced through deep X-ray lithography by spatially controlling the nanoparticle growth on the micrometer scale. The radical scavenging role of the nanocomposite films has been tested using as a benchmark the UV photodegradation of rhodamine 6G. After impregnation with a rhodamine 6G solution, samples with and without ceria have shown a remarkably different response upon exposure to UV light. The dye photodegradation on the surface of nanocomposite films appears strongly slowed down because of the antioxidation effect of ceria nanoparticles.
authors.affiliation: Laboratorio di Scienza dei Materiali e Nanotecnologie, LMNT-D.A.D.U., Università di Sassari and CR-INSTM, Palazzo Pou Salit, Piazza Duomo 6, 07041 Alghero, Sassari, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Pinna
authors.forename: Barbara
authors.initials: B
authors.lastname: Lasio
authors.forename: Massimo
authors.initials: M
authors.lastname: Piccinini
authors.forename: Benedetta
authors.initials: B
authors.lastname: Marmiroli
authors.forename: Heinz
authors.initials: H
authors.lastname: Amenitsch
authors.forename: Paolo
authors.initials: P
authors.lastname: Falcaro
authors.forename: Yasuaki
authors.initials: Y
authors.lastname: Tokudome
authors.forename: Luca
authors.initials: L
authors.lastname: Malfatti
authors.forename: Plinio
authors.initials: P
authors.lastname: Innocenzi