High Photocatalytic Activity Under Visible Light of Sandwich Structures Based on Anodic TiO2/CdS Nanoparticles/Sol–Gel TiO2

In order to increase the catalytic activity of titanium dioxide (TiO2) under visible light, a method for the synthesis of a complex sandwich catalyst based on nanotubular and sol–gel TiO2 and colloidal cadmium sulfide (CdS) was developed. The use of titanium dioxide in the form of nanotubes allowed increasing the specific surface area of the catalyst, which is one of the main factors in increasing the efficiency of the catalysis process. At the same time, the presence of CdS nanoparticles made it possible to widen the spectral range of irradiation used. Using the methods of X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy a comprehensive characterization of the synthesized samples was carried out. In addition, their chemical and phase composition, as well as the size of the nanoparticles and their morphology, were established. The photocatalytic activity was determined under the visible light and ultraviolet of nanostructures in reactions involving the oxidation of acetone in the gas phase.