title: TRMC, XPS, and EPR characterizations of polycrystalline TiO2 porphyrin impregnated powders and their catalytic activity for 4-nitrophenol photodegradation in aqueous suspension.
abstract: Characterization of polycrystalline TiO(2) bare or porphyrin impregnated powders, used as photocatalysts for the degradation of 4-nitrophenol (4-NP) in aqueous suspension, was performed by time-resolved microwave conductivity (TRMC) measurements and electronic paramagnetic resonance (EPR) and X-ray photoelectron (XPS) spectroscopies. The presence of porphyrin sensitizers, as the metal-free or Cu [5,10,15,20-tetra (4-tert-butylphenyl)] porphyrin, impregnated onto the TiO(2) surface improved the photocatalytic activity of the bare TiO(2). TRMC measurements indicate that the number and lifetime of the photoinduced excess charge carriers increase in the presence of the macrocycles, and EPR and XPS spectroscopies support the mechanistic hypotheses based on the photoreactivity experiments.
authors.affiliation: Dipartimento di Ingegneria dell'Innovazione, Università di Lecce, Via Arnesano, 73100 Lecce, Italy. giuseppe.mele@unile.it
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Mele
authors.forename: Roberta
authors.initials: R
authors.lastname: Del Sole
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Vasapollo
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Marcì
authors.forename: Elisa
authors.initials: E
authors.lastname: Garcìa-Lopez
authors.forename: Leonardo
authors.initials: L
authors.lastname: Palmisano
authors.forename: Juan M
authors.initials: JM
authors.lastname: Coronado
authors.forename: María D
authors.initials: MD
authors.lastname: Hernández-Alonso
authors.forename: Cosimino
authors.initials: C
authors.lastname: Malitesta
authors.forename: Maria Rachele
authors.initials: MR
authors.lastname: Guascito
mesh_terms: D002384:Catalysis; D003460:Crystallization; D004553:Electric Conductivity; D008872:Microwaves; D015394:Molecular Structure; D009596:Nitrophenols / Q000737:chemistry*; D010777:Photochemistry; D011166:Porphyrins / Q000737:chemistry*; D013057:Spectrum Analysis; D013997:Time Factors; D014025:Titanium / Q000737:chemistry*
chemical_list: D009596:Nitrophenols; D011166:Porphyrins; C009495:titanium dioxide; D014025:Titanium; C024836:4-nitrophenol