A straight forward, simple and inexpensive process has been developed by sol-gel method for the synthesis of manganese (Mn) doped and undoped TiO2 photocatalysts. X-ray powder diffractometry (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed the presence of structural nanoparticles with an average nanocrystalline size of about 20 nm. FT-IR/vis adsorption has shown enhanced sub-band-gap absorption as a function of Mn concentration. The photocatalytic activity of these materials was evaluated by the degradation of a basic Methylene Blue (MB) as organic contaminant. Mn-doped TiO2 powder with molar ratio 0.1:100 was mixed with calcareous filler (5% and 10% respectively) and the photocatalytic activity was evaluated by the degradation of inorganic pollutants such as NOx under UV and visible light. (C) 2011 Elsevier B.V. All rights reserved.