This paper reports the results of a study on the surface fluorinated titanium dioxide Wackherr's "Oxyde de titane standard", which shows very interesting photocatalytic activity. Characterization of F-TiO2 Wackherr reveals that F-TiO2 has smaller size compared to TiO2 Wackherr. The effect of fluoride ions on photocatalytic activity of TiO2 Wackherr in the degradation of a chlorotriazine azo dye Reactive Orange 4 (RO 4) under ambient conditions using UV light was investigated. The degradation rate of RO 4 with surface fluorinated TiO2 Wackherr is 2.4 times faster than TiO2-Wackherr. The degradation rate of UV/TiO2-Wackherr process is largely decreased by the increase of initial dye concentration, whereas in UV/F-TiO(2)Wackherr process, the influence of initial dye concentration is minimum. F-TiO2 Wackherr catalyst is suitable for the treatment of dye industrial wastewater at higher concentration. The optimum operating conditions of UV/F-TiO2 Wackherr process for efficient dye degradation are reported. (C) 2013 Elsevier B.V. All rights reserved.