The present study investigated the photodegradation of 2,4-Dichlorophenoxyacetic acid (2,4-D) in a water environment using synthesized titania nanoparticles (TiO2-NPs). The TiO2-NPs fabricated by sol-gel method were distinguished by X-ray diffraction (XRD) and Transmission electron microscopy (TEM), Infrared spectroscopy (IR), and zeta potential measurements. The results indicated that TiO2 - NPs were nanospheres of appropriately 30nm with a major anatase phase. Synthesized TiO2-NPs have the point of zero charge (PZC) of around 6.0. The efficient conditions for photocatalysis degradation of 2,4-D under sunlight were considered and found to be 120 min, pH 11, and 1 mM KCl. Under ideal conditions, the photodegradation efficiency of 2,4-D reached greater than 72 %. Our results suggest that TiO2-NPs would be promisingly applied for eliminating 2,4-D from an aqueous solution.

The present study investigated adsorption of 2,4-dichorophenoxy acetic acid(2,4-D) on titania (TiO2) nanoparticles with surface modification by cationic surfactant, cetyltrimethylammonium bromide (CTAB). Titania nanoparticles which were successfully synthesized by sol-gel method, were characterized by X-ray diffraction (XRD) and Transmission electron microscopy (TEM). Surface modification of TiO2 with CTAB enhanced the removal of 2,4-D significantly. Some effective conditions affect to the removal of 2,4-D using CTAB modified TiO2 such as pH and adsorbent dosage were systematically studied and found to be 5 and 10 mg/mL, respectively. Adsorption mechanisms of 2,4-D onto CTAB modified TiO2 was suggested based on the change in surface charge after adsorption.