CuO/ZnO/g-C₃N₄ heterostructures as efficient visible light-driven photocatalysts

Photocatalytic degradation of organic pollutants is an environmentally friendly technique for water treatment. In this work, CuO/ZnO/g-C₃N₄ heterostructure is prepared via solution combustion route to take advantage of the porous structure which is resulted from releasing the gases during the combustion. XRD, EDX, TEM, XPS, and TEM analyses confirm the successful construction of CuO/ZnO/g-C₃N₄ heterostructure. SEM images reveal that the as-prepared heterostructure consists of flower-like nanosheets decorated with nanoparticles. The CuO/ZnO/g-C₃N₄ heterostructure exhibits improved photocatalytic activity for methylene blue (MB) degradation in comparison to the CuO/ZnO system under visible light irradiation. At optimal experimental conditions, about 98% of MB is degraded within 45 »min. Moreover, about 91% of ammonia- nitrogen is degraded after 6 »h visible light illumination. The enhanced photocatalytic activity is attributed to the improved redox potential of the photocatalyst and efficient electrons and holes separation induced by the Z-scheme charge carrier transfer.