Open AccessCarbon-Doped Titanium Dioxide: Visible Light Photocatalysis and EPR Investigation
Author(s) -
Е. А. Константинова,
А. И. Кокорин,
S. Sakthivel,
Horst Kisch,
Klaus Lips
Publication year - 2007
Publication title -
chimia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.387
H-Index - 55
eISSN - 2673-2424
pISSN - 0009-4293
DOI - 10.2533/chimia.2007.810
Subject(s) - electron paramagnetic resonance , photocatalysis , photoexcitation , photochemistry , visible spectrum , titanium dioxide , irradiation , doping , carbon fibers , materials science , ultraviolet light , ultraviolet , carbon dioxide , analytical chemistry (journal) , chemistry , optoelectronics , nuclear magnetic resonance , catalysis , organic chemistry , excited state , atomic physics , physics , composite number , nuclear physics , metallurgy , composite material
X-band EPR studies of a series of undoped and carbon-doped titania powders reveal the presence of a carbon-centered radical species. The concentration of spins is five to six orders of magnitude smaller than the total carbon content. Photoexcitation of the carbon-doped samples increases the corresponding EPR signal intensities both under ultraviolet and visible light irradiation. After illumination, the original intensity is restored within a few hours. Samples with higher carbon radical concentration reveal higher photocatalytic activity in degradation of 4-chlorophenol under visible light irradiation.