In the present study, ZnO nanoparticles have been successfully synthesized by modified sol - gel method using zinc nitrate (Zn(NO 3 ) 2 .6H 2 O) as a precursor and The different combinations of triethanolamin, ( C 6 H 15 O 3 N) for the first time and , citric acid (C 6 H 8 O 7 ) with different proportio were added as surfactants to control the particle size. The Samples were characterized by X-ray diffraction (XRD), Fourier transform Infrared (FT- IR) spectroscopy, scanning electron microscopy (SEM), Ultraviolet–visible (UV–VIS) spectroscopy and photoluminescence (PL) techniques. The XRD results revealed the hexagonal wurtzite structure of the ZnO nanostructures for all the samples. The average crystallite size calculated from Scherrer’s relation was found to be 27.5 nm. The photocatalytic activity of ZnO nanoparticles was examined for photocatalytic degradation of methyl blue (MB), methyl orange (MO) and methylene red (MR) solutions. The results also showed that ZnO nanoparticles revealed the highest photocatalytic activity for the destruction of these three organic dye. In addition, the product was used in decolourization processes and the treatment of textile dyes reactive blue 21, Reactive Orange 5 and Reactive Red 120.