New Composite Photocatalysts Based on the Solid Solutions of Cadmium Sulfide, Zinc Sulfide, Titania, and Platinum for the Photocatalytic Reduction of Carbon Dioxide with Water Vapor under Visible Light

Abstract

In this work, the Cd1 – xZnxS/TiO2 photocatalysts were synthesized and characterized by X-ray diffraction (XRD) analysis and diffusion reflectance spectroscopy (DRS). The catalytic properties of the obtained samples were investigated in the photocatalytic reduction of carbon dioxide with water vapor under visible light (400–510 nm; a maximum radiation intensity was at a wavelength of 450 nm). The highest catalytic activities were demonstrated by 20% Cd0.7Zn0.3S/TiO2 and 50% Cd0.7Zn0.3S/TiO2. The effect of the deposition order of the Pt, Cd0.7Zn0.3S, and TiO2 components on the efficiency of photocatalytic processes was studied. The highest reaction rates of 4.2 μmol h–1 g–1 CO and 0.6 μmol h–1 g–1 CH4 were obtained over 50%Cd0.7Zn0.3S/1% Pt/TiO2.