A New Visible-Light Photocatalyst: CdS Quantum Dots Embedded Mesoporous TiO2

• Published in: Environmental science & technology Vol. 43; no. 18; pp. 7079 - 7085
• Main Authors: Li, Gui-Sheng, Zhang, Die-Qing, Yu, Jimmy C
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 15.09.2009
• Subjects: Adsorption; Applied sciences; Cadmium Compounds - chemistry; Catalysis - radiation effects; Chlorophenols - chemistry; Exact sciences and technology; Kinetics; Light; Methylene Blue - chemistry; Microscopy, Electron, Transmission; Nitric Oxide - isolation & purification; Nitrogen - chemistry; Particle Size; Pollution; Porosity - radiation effects; Quantum Dots; Remediation and Control Technologies; Spectrophotometry, Ultraviolet; Sulfides - chemistry; Titanium - chemistry; X-Ray Diffraction; Pollutant behavior; Photocatalysis; Electron transfer; Desorption; Ultraviolet radiation; Transmission electron microscopy; Adsorption; Visible radiation; Oxidation; Titanium oxide; Catalyst; Physicochemical properties; Photochemical degradation
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/es9011993

Cadmium sulfide quantum dots (QDs) sensitized mesoporous TiO2 photocatalysts were prepared by preplanting cadmium oxide as crystal seeds into the framework of ordered mesoporous titanium dioxide and then converting CdO to CdS QDs through ion-exchange. The presence of CdS QDs in the TiO2 framework extended its photoresponse to the visible-light region by accelerating the photogenerated electron transfer from the inorganic sensitizer to TiO2. The new photocatalyst showed excellent photocatalytic efficiency for both oxidation of NO gas in air and degradation of organic compounds in aqueous solution under visible light irradiation. The photocatalysts were characterized by XRD, N2 adsorption−desorption, TEM, XPS, UV/vis, and PL spectroscopy. The relationship between the physicochemical properties and the photocatalytic performance of the sample is discussed.