Titanium dioxide (TiO2) is a well-known and studied semiconductor for its effectiveness as a nactivity mostly in the ultraviolet (UV)-spectrum. This project intends to develop and evaluate a protocol to modify the surface of TiO2 nanoparticles by adding iron ions (Fe+3) to improve its capability  to gets photoactivated under the visible spectrum. FeCl3·6H2O is being used as the source of iron and subjecting it to thermal treatments at high temperatures. Parameters of concentration of (Fe+3)   , time and temperature of the heat treatment were varied with the intention of finding the combination where the highest absorption of visible light is obtained. The concentrations were 1, 2 and 3% M for temperatures and times of 850 950 and 1050 °C and 2, 4 and 6 h, respectively. It was found that the highest absorbance occurs when the surface is modified with concentration of 1% M, at 850C with 4h of treatment in the oven. These samples when characterized with the Spectometer-UV showed that the absorption of the material moved to the visible range, having a maximum absorbance peak at 526nm. In the other hand, by analyzing the samples with X-ray diffraction (XRD) it was observed that the crystal structure of the TiO2 remained constant without any structure of any other compound being observed. With this modification, we are working to test and implement the photodegradation properties of TiO2 in such a way that it could degrade organic compounds in water under visible light.