This study synthesized nanocomposite photocatalyst materials from a mixture of Cu2O nanoparticles, ZnO nanoparticles, and graphene oxide (GO) through coprecipitation and hydrothermal methods. This study aims to determine the optimum composition of Cu2O/ZnO/GO nanocomposites in degrading methylene blue. The nanocomposite was synthesized in two steps: 1 the synthesis of Cu2O and ZnO nanoparticles through the coprecipitation method and the preparation of GO through the modified Hummer method. 2 The preparation of Cu2O and ZnO nanoparticles mixtures with GO through the hydrothermal method to form Cu2O/ZnO/GO nanocomposites. The adsorption-photocatalysis process of methylene blue was done with UV light from a halogen lamp. The characterization results indicated that the optimum composition was Cu2O/ZnO nanocomposite with a ratio of 1:2 and 10% of GO, which had a specific surface area of 35.874 m2 g-1, a pore radius of 19.073 nm, and a pore volume of 0.092 cm3 g-1, and a diameter crystalline of 31.19 nm. The degradation efficiency of methylene blue under UV light for 120 minutes were 82.0%, 86.0%, 91.4%, and 79.3% using the Cu2O/ZnO nanocomposites with GO of 1%, 3%, 5%, and 10%, respectively. These results indicated that Cu2O/ZnO/GO nanocomposites efficiently degrade methylene blue from textile dye waste.
