TRMC, XPS, and EPR characterizations of polycrystalline TiO2 porphyrin impregnated powders and their catalytic activity for 4-nitrophenol photodegradation in aqueous suspension.
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.
Mele
Giuseppe
G
Dipartimento di Ingegneria dell'Innovazione, Università di Lecce, Via Arnesano, 73100 Lecce, Italy. giuseppe.mele@unile.it
Del Sole
Roberta
R
Vasapollo
Giuseppe
G
Marcì
Giuseppe
G
Garcìa-Lopez
Elisa
E
Palmisano
Leonardo
L
Coronado
Juan M
JM
Hernández-Alonso
María D
MD
Malitesta
Cosimino
C
Guascito
Maria Rachele
MR
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*
D009596:Nitrophenols; D011166:Porphyrins; C009495:titanium dioxide; D014025:Titanium; C024836:4-nitrophenol