LAUSR

Abstract The micron-size flower-like metal oxide of copper/zinc decorated graphitic carbon nitride (g–C3N4–CuO/ZnO) composite was successfully synthesized by solvent mixing assisted with the sonication method. The structural, functional groups, morphology, particle size, optical properties of synthesized g–C3N4–CuO/ZnO composites were analyzed using various techniques such as XRD, XPS, FTIR, SEM, TEM, UV–Vis, photoluminescence (PL), and photocurrent–time (PT) measurements. Further, the photocatalytic capacity of the synthesized composite was examined by the evolution of hydrogen production through the water-splitting using visible light and the study of methylene blue dye (MB) degradation under solar irradiation. The g–C3N4–CuO/ZnO composites showed the enhanced photocatalytic activity as compared to the pure bulk form of g-C3N4, DMSO-g-C3N4, and CuO/ZnO. Also, it showed an increment of photocatalytic activity in the treatment of pollutants as well as increased production of hydrogen gas under visible light. These enhanced photocatalytic activities could be attributed to the combined effect between g-C3N4 and CuO/ZnO crystalline phases. The maximum quantum efficiency and degradation of the MB dye by g–C3N4–CuO/ZnO composite were 5.5% and 99%, respectively. The mechanism of enhanced photocatalytic activity of the g–C3N4–CuO/ZnO composite was also discussed in this work.