A series of bimetallic titania-supported copper-nickel (Cu-Ni/TiO2) photocatalysts were synthesized using sol-gel associated hydrothermal method coupling with design of experiment (DOE). Central composite design (CCD) was applied to study the single and combined effects of three primary parameters H2O, acid and Cu ratio to titanium tetraisopropoxide on the optical properties of Cu-Ni/TiO2. The absorbance of all photocatalysts were extended to the visible region with lower bandgap energies compared to commercial TiO2 (P25. Analysis of variance (ANOVA) revealed a second- order polynomial regression model to fit the experimental data in CCD. A comparison between predicted and experimental values represented a reasonable agreement amongst them with high coefficient of determination value (R2=0.94). The 3-D response surface plots imply that parameter water was more effective compared to the other parameters. © 2016 The Authors.