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Stimulated Raman scattering spectra of benzil (C 14 H 10 O 2 ) crystal were measured using picosecond pumping at 300 K. Their lasing components are related to those of polarized IR and spontaneous Raman spectra of an oriented crystal. The nature and assignment of vibrational modes are discussed on the basis of quantum chemical calculations. The B3LYP and MPW1PW91 hybrid functionals that include a mixture of HF and DFT exchange correlation were applied. The results of the chemical quantum calculations were compared with those of normal coordinate analysis performed previously. The role of the anharmonic effects was analyzed and the scaling factors of the vibrational wavenumbers were determined.

Sulfated (5wt.%) ZrO2 and non-sulfated ZrO2 modified by NH4VO3 using incipient wetness impregnation technique to achieve a loading of 5wt.% V2O5 were thoroughly characterized by means of X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy, N2 sorptiometry, particle size analyzer and pyridine-FT-IR that was used to investigate the acidity of the samples. Degradation of direct blue-1 (DB) dye was tested for the effectiveness of the samples. The results revealed that DB degradation was highly improved with V supported on ZrO2-SO4 and showed a conversion comprises of 95% after UV irradiation (emitting at 365 nm) for 60 min exceeding that of SO4 free ZrO2 sample (68%) obtained at the same period of illumination. This was due to the large surface area (183 m 2 g-1), small crystallites size and presence of basic sites namely O2 − and OH − moieties, those take part in the reaction as additional oxidizing agents. The photocatalytic degradation of DB was found to follow first order rate kinetics. More information on the activity, surface texturing, kinetics and TOC removal were well evaluated, compared and discussed for all samples.