Impact of different Cu sources on the structure, surface morphology, optical and photocatalytic characteristics of sol-gel derived CuO thin films

In this study, the impact of different Cu sources has been scrutinized on the structure, surface morphology, optical, and photocatalytic properties of CuO thin films, synthesized by sol-gel dip coating have been investigated. X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) mapping, and UV–Vis spectroscopy were utilized to scrutinize them. The XRD patterns showed that the CuO films had a monoclinic CuO phase with a polycrystalline nature and their crystalline quality depended on the used Cu-source. Comparatively, the highest crystalline quality was observed for CuO film derived from the Cu-acetate source. The EDS and elemental mapping analysis exhibited the presence of Cu and O atoms within the film composition, randomly distributed on the film facets. As observed from the SEM analysis, the surface morphologies and grain sizes of CuO films were mainly changed by the Cu chemical source used. Variation in UV–Vis absorbance reflects different surface morphology and defect levels as the Cu-source was changed. The synthesized nanostructured CuO thin films showed highly varied photocatalytic activities and degradation rate of methylene blue dye solution under solar radiation. Among all synthesized CuO thin films, derived by using a Cu-chlorite source showed the highest photocatalytic efficacy within 150 min.