In this study, different nano-catalysts of Fe-TiO 2 , Al 2 O 3 /TiO 2 , Fe-TiO 2 /Al 2 O 3 were synthesized by sol-gel technology. In order to study the performance of synthesized catalysts, the photocatalytic degradation of Direct-Red 16 dye under visible light investigated. Similar operational conditions and easier measurement of the dye contaminant compared to the nitrate ion caused the use of Direct Red 16 to confirm the performance of the catalysts. Based on preliminary the Direct Red 16 dye degradation tests were performed within range of 3-7 weight percent for Fe-TiO 2 and 0.1 to 0.3 weight ratio for Al 2 O 3 /TiO 2 . Optimum amount of Fe-TiO 2 /Al 2 O 3 nano-catalyst contents by RSM method were obtained, 7wt.%Fe 3+ /Ti 4+ with weight ratio of 0.11 for Al 2 O 3 /TiO 2 at pH 6.8. In the second step, to optimize the content of Fe-TiO 2 /Al 2 O 3 in nano-catalyst powder and to obtain the optimum conditions for nitrate ion reduction experiment, Design Expert software was implemented, in which the RSM method with central composite design were used. The parameter of doping amount of iron ion to titanium ion (wt.% Fe 3+ /Ti 4+ ), the amount of alumina relative to TiO 2 (TiO 2 /Al 2 O 3 ), and the formic acid ratio (as the electron donor or hole scavenger) to the nitrate ion, were simultaneously examined at three levels. The concentration of catalyst and initial concentration of nitrate ion were 1g/L and 100ppM NO 3 -N, respectively. The highest photocatalytic activity for powdered nano-catalyst with content of 6.23wt.% Fe-TiO 2 /Al 2 O 3 and a weight ratio of 0.13 for Al 2 O 3 /TiO 2 , with the ratio of formic acid to nitrate ion 5.14 M/M under visible light was obtained equal of 17.82 % in 360 minutes. All experiments were performed at ambient temperature of (25 ± 0.5)°C. The optimum nano-catalysts obtained in powder form were studied by ultraviolet irradiation to reduce nitrate ion and was obtained equal of 87 % under a period of 120 minutes. In the third step, the optimum contents of synthesized nano-catalyst in powder form, was deposited over a glass substrate in the form of a thin three layers film. The maximum photocatalytic reduction efficiency of nitrate ion by this nano-catalyst was obtained equal of 13.4 % irradiation of visible light under a period of 360 minutes. Keywords: Photocatalytic, Fe-TiO 2 /Al 2 O 3 , Direct Red 16, Nitrate ‌Ion, RSM, Powder nano-catalyst, Thin Film Layer, Visible Light, UV Irradiation.