Carbon-Deposited TiO2: Synthesis, Characterization, and Visible Photocatalytic Performance

Carbon-depositcd TiO2 (TiO2@C) was prepared with a one-pot hydrothermal process by using glucose as a carbon Source. The physical properties of TiO2@C were studied by XRD, TG-DTA, HRTEM, and UV-vis diffuse reflectance spectra (DRS), while the chemical states of carbon were discussed via X-ray photoelectron spectroscopy (XPS.). A graphite carbon layer Was formed Out of the TiO2 grain during the hydrothermal process via the dehydration of glucose, which consisted of not only C, but also C-OH (and C-O-C) and C=O (and COO). TiO2@C hits remarkable light absorption in the visible region. It was found that the photocatalytic activity of TiO2@C was greatly enhanced compared to noncarbon-TiO2 under visible irradiation. The photocatalyst with the highest photocatalytic activity for the degradation of Acid Orange 7 (AO7) was G15 TiO2@C, while that for the degradation of 2,4-dichlorophenol (2,4-DCP) was G5 TiO2@C. Two kinds of sensitization processes, carbon sensitization and dye sensitization, are responsible for the visible light-induced photocatalysis of TiO2@C. Carbon sensitization reached its optimal condition in G5, while dye sensitization occurred in its maximum efficiency in G15.