Photocatalyzed degradation of flumequine by doped TiO sub(2) and simulated solar light

Titanium dioxide was obtained in its pure form (TiO sub(2)) and in the presence of urea (u-TiO sub(2)) and thiourea (t-TiO sub(2)) using the sol-gel technique. The obtained powders were characterized by BET surface area analysis, Infrared Spectroscopy, Diffuse Reflectance Spectroscopy and the Rietveld refinement of XRD measurements. All the prepared catalysts show high anatase content (>99%). The a and b-cell parameters of anatase increase in the order TiO sub(2)TiO sub(2). The photocatalytic activities of the samples were determined on flumequine under solar-simulated irradiation. The most active catalysts were u-TiO sub(2) and t-TiO sub(2), reaching values over 90% of flumequine degradation after 15min irradiation, compared with values of 55% for the pure TiO sub(2) catalyst. Changing simultaneously the catalyst amount (t-TiO sub(2)) and pH, multivariate analysis using the response surface methodology was used to determine the roughly optimal conditions for flumequine degradation. The optimized conditions found were pH below 7 and a catalyst amount of 1.6gL super(-) super(1).