Self-cleaning activity of CuO/ZnO heterostructure: A synergy of photocatalysis and hydrophilicity

Self-cleaning surface using metal oxide semiconductors has gained considerable attention for their unique properties and practical applications. The self-cleaning performance was realized using photocatalytic hydrophilic material where UV irradiation breaks down the pollutants and hydrophilicity sweeps them away. CuO, ZnO and CuO/ZnO thin films were prepared by sol-gel spin coating method. The self-cleaning activity is evaluated through the degradation of organic pollutants from the surface. Herein, we report a successful preparation of an active, CuO/ZnO heterostructure photocatalyst for self-cleaning applications. XRD and TEM analysis confirms the formation of heterostructure between CuO and ZnO. XPS analysis confirms the +2 oxidation state of zinc and copper in the samples. Contact angle studies show the hydrophilicity of CuO/ZnO heterostructure. The photocatalytic activity of CuO/ZnO heterostructure is significantly higher than that of single-phase CuO and ZnO. The enhancement in photocatalytic activity is attributed to the effective separation of charge carriers due to the formation of the heterostructure. The self-cleaning activity is evaluated by the decomposition of octadecanoic acid measured through the change in contact angle values and FT-IR. This research will provide a promising approach in designing a heterostructured photocatalytic system for its potential in self-cleaning applications.