This study aims to investigate the photocatalytic process for the removal of methyl red dye from wastewater. To evaluate the structure of the photocatalyst, FTIR, XRD, and SEM analyses were performed. The effect of various parameters such as tin dioxide to graphene oxide ratio, adsorbent dosage, process time, and lamp type on the removal rate of methyl red dye was investigated. After conducting the experiments according to the experimental design order and reviewing the obtained data, the photocatalyst with a ratio of tin dioxide to graphene oxide of 7.5:1 g/g was selected as the optimal photocatalyst. Also, the removal rate of methyl red obtained at photo catalyst doses of 0.04 and 0.06 g/L had equal removal rates, and as a result, the dose of 0.04 g/L was selected as the optimal catalyst dose. The removal rate of 93% of methyl red was obtained as the highest efficiency by tungsten lamp at 60 min. The results showed that at 10 min, 75% of methyl red was removed and by 60 min the slope of the removal curve was very gentle and reached a constant value. Finally, it was determined that the pseudo-second-order kinetic model has better accuracy in matching the experimental data.
