Electrodeposition of TiO2/CdS 3D lotus flower-like clusters and TiO2/Gd2O3 1D nanorods arrays electrodes: growth mechanisms and red shifting the optical response for photocatalytic applications

Abstract Using the electrodeposition technique, nanocomposite thin films of ITO/TiO₂, ITO/TiO₂/CdS, and ITO/TiO₂/Gd₂O₃ were successfully fabricated on ITO glass substrates. The structural, morphological, and optical properties of the prepared films were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV–visible spectrophotometry. Distinct nanostructured morphologies were observed, including nanospheres, cauliflower-like structures, and flower-like architectures for ITO/TiO₂, ITO/TiO₂/CdS, and ITO/TiO₂/Gd₂O₃ films, respectively. UV–visible analysis revealed a reduction in the optical band gap and a red-shifted absorption edge for the CdS- and Gd₂O₃-modified films compared to pristine ITO/TiO₂. These findings highlight a clear correlation between the electrodeposited nanostructures and their optical response, providing insight into the growth mechanism and structure optical property relationship of the fabricated thin films, with relevance for future photocatalytic studies. Graphical abstract