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Title: Visible light activated photocatalytic behaviour of rare earth modified commercial TiO{sub 2}

Highlights: • RE gave more surface hydroxyl groups attached to the photocatalyst's surface. • RE gave the modified and fired samples a high specific surface area. • Photocatalytic activity was assessed in gas–solid phase under visible-light exposure. • Thermal treated RE-TiO{sub 2}s showed a superior visible-light photocatalytic activity. • La-TiO{sub 2} was the best performing photocatalyst. - Abstract: A commercial TiO{sub 2} nanopowder, Degussa P25, was modified with several rare earth (RE) elements in order to extend its photocatalytic activity into the visible range. The mixtures were prepared via solid-state reaction of the precursor oxides, and thermally treated at high temperature (900 and 1000 °C), with the aim of investigating the photocatalytic activity of the thermally treated samples. This thermal treatment was chosen for a prospective application as a surface layer in materials that need to be processed at high temperatures. The photocatalytic activity (PCA) of the samples was assessed in gas–solid phase – monitoring the degradation of isopropanol (IPA) – under visible-light irradiation. Results showed that the addition of the REs lanthanum, europium and yttrium to TiO{sub 2} greatly improved its photocatalytic activity, despite the thermal treatment, because of the presence of more surface hydroxyl groups attached to themore » photocatalyst's surface, together with a higher specific surface area (SSA) of the modified and thermally treated samples, with regard to the unmodified and thermally treated Degussa P25. The samples doped with La, Eu and Y all had excellent PCA under visible-light irradiation, even higher than the untreated Degussa P25 reference sample, despite their thermal treatment at 900 °C, with lanthanum producing the best results (i.e. the La-, Eu- and Y-TiO{sub 2} samples, thermally treated at 900 °C, had, respectively, a PCA equal to 26, 27 and 18 ppm h{sup −1} – in terms of acetone formation – versus 15 ppm h{sup −1} for the 900 °C thermally treated Degussa P25). On the other hand, Ce–TiO{sub 2}s had no significant photocatalytic activity.« less
Authors:
 [1] ;  [1] ;  [2] ; ;  [1]
  1. Department of Materials and Ceramic Engineering/CICECO, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro (Portugal)
  2. Slovenian National Building and Civil Engineering Institute, Dimičeva 12, SI-1000 Ljubljana (Slovenia)
Publication Date:
OSTI Identifier:
22345211
Resource Type:
Journal Article
Resource Relation:
Journal Name: Materials Research Bulletin; Journal Volume: 50; Other Information: Copyright (c) 2013 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 77 NANOSCIENCE AND NANOTECHNOLOGY; ACETONE; DOPED MATERIALS; EUROPIUM; HEAT TREATMENTS; HYDROXIDES; IRRADIATION; LANTHANUM; MIXTURES; NANOSTRUCTURES; OPTICAL PROPERTIES; PHASE TRANSFORMATIONS; PHOTOCATALYSIS; POWDERS; PROPANOLS; RAMAN SPECTROSCOPY; SOLIDS; SPECIFIC SURFACE AREA; TITANIUM OXIDES; YTTRIUM