On the Formation of TiO₂–ZnO Composite Layers with Increased Photosensitivity by Electrophoretic Deposition

Enhancing the photosensitivity of titanium dioxide TiO₂ by shifting the absorption spectrum to the long-wavelength region of the solar spectrum is a critical task. This problem can be solved by the modification of TiO₂, e.g., by the formation of heterostructures with another semiconductor material. In this work, the development of a technique for the formation of photoactive TiO₂–ZnO composite layers using electrophoretic deposition is presented. The results of studying the photosensitivity of TiO₂ and TiO₂–ZnO samples on a silicon substrate coated with carbon nanotubes are given. The formation of TiO₂–ZnO composite layers by electrophoretic deposition is carried out using stabilizing additives: sodium lauryl sulfate and hydroxypropylcellulose. As a result layers of TiO₂–ZnO/carbon nanotube composite material are obtained; their morphology is studied by scanning electron microscopy (SEM). It is demonstrated that the addition of 50 wt % of zinc oxide ZnO to the suspension provides the formation of TiO₂–ZnO composite material with a ZnO content of 30 wt %. Studying the obtained layer’s photosensitivity by chronoamperometry shows an increase in the generated photocurrent by 5 times when using the full spectrum of a xenon lamp in comparison with a similar structure based on commercial P25 TiO₂.