Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
67427 | Journal of Molecular Catalysis A: Chemical | 2008 | 5 Pages |
A series of Ce-TiO2/SiO2 (Ce-TiO2 coatings on SiO2) were prepared by the sol–gel process and characterized by TG–DTA, XRD, SEM, XPS and DRS. The photocatalytic activities of Ce-TiO2/SiO2 for the oxidation of formaldehyde irradiated by 250 W high-pressure mercury lamp were investigated. According to XPS investigation, the Ti element mainly existed as the chemical state of Ti4+, and Ce is present mainly in the +4 oxidation state and a little in the +3 oxidation state. The effect of cerium content on the photocatalytic activities was studied, and the result reveals that 0.10%Ce-TiO2/SiO2 exhibits highest photoactivity. The light absorption of Ce-TiO2/SiO2 increases with increasing cerium content, and cerium doping causes absorption spectra of Ce-TiO2/SiO2 to shift to the visible region. The high photocatalytic activity of Ce-TiO2/SiO2 can be explained by the effective separation of photogenerated electron–hole pairs, which are trapped by Ce4+ and hydroxyl groups balancing the positive charge generated by the incorporation of Si in a Ti matrix, respectively.
Graphical abstractThe high photocatalytic activity of Ce-TiO2/SiO2 can be explained by the effective separation of photogenerated electron-hole pairs, which are trapped by Ce4+ and hydroxyl groups balancing the positive charge generated by the incorporation of Si in a Ti matrix, respectively.Figure optionsDownload full-size imageDownload as PowerPoint slide