In this research, the dye photo-catalytic removal was investigated using zirconia (ZrO$_2$) nanocatalysts, zeolite (Ze), ZrO$_2$–Ze with different percentages and optimized ZrO$_2$–Ze doped via urea, copper oxide and cerium oxide. In order to determine the optimal conditions, the effects of different catalysts and parameters such as dye concentration, UV lamp power, amount of the loaded catalyst and pH were investigated. The response surface methodology was used to obtain optimal experimental conditions. Physical and chemical properties of materials were investigated by X-ray diffraction,Fourier transform infrared, scanning electron microscopy and Brunauer–Emmett–Teller. Completely methyl orange (MO)-dye removal (100%) was achieved at optimal conditions under UV light during 80 min. The optimal operational condition for MO photo-catalytic decomposition using an optimal N-doped 10 wt% ZrO$_2$–zeolite nanocatalyst was obtained at UV lamp power, pH, catalyst loading and dye concentration of 15 W, 3, 0.4 g l$^{−1}$ and 5 mg l$^{−1}$, respectively. Photo-catalytic degradation kinetics of MO described well using pseudo-first order which is in accordance with the Langmuir–Hinshelwoodmodel ($k_{\rm app}$ = 0.031$ min$^{−1}$).