The environmental pollution has become an important problem of our days. The huge development of textile industry and specially agrochemicals have led to increase the number of different dyes, pesticides and herbicides in ground water and surface waters. They have negative effects on human health and aquatic ecosystems [1]. Thus, a way to overcome these effects is to find a process through which the used chemicals are destroyed. Our work reports a new synthesized mesoporous titania TiO2 nanoparticles, involving ultrasound-assisted sol-gel method.In the typical synthesis procedure titanium isopropoxide was used as titania precursor and surfactant F127 was used as structure directing agent. When the sol was maturated, the precipitate have been separated by centrifugation, washed several times with distilled water and dried at room temperature. Afterward, the solid obtained was subjected to the thermal treatment for 4 hours, at 723,15 K, performing that way the pore emptying. By varying the surfactant/titanium-source weight ratio, as well as the ultrasonation time, nine titania samples have been obtained.The influence of the surfactant/titanium source weight ratio and different ultrasonication time on the textural, structural and morphological properties has been investigated by various physicochemical techniques (X-ray diffraction, UV Diffuse Reflectance, Nitrogen Sorption Measurements, Fourier Transform Infra Red spectroscopy, Scanning Electron Microscopy). Afterward, the synthesized titania samples have been tested in the photodegradation process of Congo Red (dye) and 2,4-dichlorophenoxyacetic acid (herbicide). Both molecules have been choosed as model molecules to be degraded by the synthesized photocatalyst under UV-light. The obtained data have been compared and the most efficient catalyst could be used in photodegradation of such molecules.