The Composite TiO(2)–CuO(x) Layers Formed by Electrophoretic Method for CO(2) Gas Photoreduction

This study demonstrates the ability to control the properties of TiO(2)–CuO(x) composite layers for photocatalytic applications by using a simple electrophoretic deposition method from isopropanol-based suspension. To obtain uniform layers with a controlled composition, the surfactant sodium lauryl sulfate was used, which influenced the electrophoretic mobility of the particles and the morphology of the deposited layers. The TiO(2)–CuO(x) composite layers with different CuO(x) contents (1.5, 5.5, and 11 wt.%) were obtained. It is shown that the optical band gap measured by UV–VIS–NIR diffuse reflectance spectra. When CuO(x) is added to TiO(2), two absorption edges corresponding to TiO(2) and CuO(x) are observed, indicating a broadening of the photosensitivity range of the material relative to pure TiO(2). An open-circuit potential study shows that by changing the amount of CuOx in the composite material, one can control the ratio of free charge carriers (n and p) and, therefore, the catalytic properties of the material. As a result, the TiO(2)–CuO(x) composite layers have enhanced photocatalytic activity compared to the pure TiO(2) layer: methanol yield grows with increasing CuO(x) content during CO(2) photoreduction.