Spectral dependences of the activity and selectivity of N-doped TiO2 in photodegradation of phenols

In present study we report the spectral dependencies of the quantum yield of phenol and 4-chlorophenol photodegradation over N-doped TiO2 and the selectivity of the photocatalyst toward formation the major intermediates. Applying the theoretical model developed earlier [A.V. Emeline, V.K. Ryabchuk, N. Serpone, J. Phys. Chem. B. 103 (1999) 1316; AN. Emeline. AN. Frolov, V.K. Ryabchuk, N. Serpone, J. Phys. Chem. B 107 (2003) 7109] for analysis of the experimental spectral dependencies we conclude that extrinsic N-doped induced absorption is formed by overlapping of several single absorption bands, which presumably correspond to different intrinsic defects (color centers) in TiO2 distinguished by different efficiency of photogeneration of charge carriers. It is also inferred that measurement and corresponding analysis of spectral dependencies of the quantum yield and selectivity of heterogeneous photochemical reactions can be considered as a powerful spectroscopic mean to deconvolve the complex non-resolved absorption spectrum of solids. (C) 2009 Elsevier B.V. All rights reserved.