Photocatalysis with chromium-doped TiO2: Bulk and surface doping

Samy Ould-Chikh, Olivier Proux, Pavel V. Afanasiev, Lhoussain Khrouz, Mohamed N. Hedhili, Dalaver H. Anjum, Moussab Harb, Christophe Geantet, Jean-Marie Basset, Eric Puzenat

Research output: Contribution to journalArticlepeer-review

75 Scopus citations

Abstract

The photocatalytic properties of TiO2 modified by chromium are usually found to depend strongly on the preparation method. To clarify this problem, two series of chromium-doped titania with a chromium content of up to 1.56 wt % have been prepared under hydrothermal conditions: the first series (Cr:TiO2) is intended to dope the bulk of TiO2, whereas the second series (Cr/TiO2) is intended to load the surface of TiO2 with Cr. The catalytic properties have been compared in the photocatalytic oxidation of formic acid. Characterization data provides evidence that in the Cr/TiO2 catalysts chromium is located on the surface of TiO2 as amorphous CrOOH clusters. In contrast, in the Cr:TiO 2 series, chromium is mostly dissolved in the titania lattice, although a minor part is still present on the surface. Photocatalytic tests show that both series of chromium-doped titania demonstrate visible-light-driven photo-oxidation activity. Surface-doped Cr/TiO2 solids appear to be more efficient photocatalysts than the bulk-doped Cr:TiO2 counterparts. It's classified! The photocatalytic properties of TiO2 modified by chromium depend strongly on the preparation method. To clarify this problem, two types of modified titania are discussed: one with CrIII doped in the bulk and one with CrOOH clusters on the TiO2 surface (see picture). Both series show visible-light-driven photo-oxidation activity. However, surface modification appears to be a more efficient strategy. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Original languageEnglish (US)
Pages (from-to)1361-1371
Number of pages11
JournalChemSusChem
Volume7
Issue number5
DOIs
StatePublished - Apr 15 2014

Bibliographical note

KAUST Repository Item: Exported on 2020-10-01
Acknowledgements: We gratefully acknowledge the King Abdullah University of Science and Technology for support of this research through the CADENCED project. The analytical service of IRCELYON is acknowledged for elemental analysis. We acknowledge the KAUST Imaging and Characterization core lab, and scientific and technical assistance of Drs. Rachid Sougrat (TEM), Yang Yang (Raman), and Bei Zhang (SQUID). Yves Joly (Institut Neel) is kindly acknowledged for fruitful discussions related to XANES and his assistance with using the FDMNES code. Anna Carlsson is thanked for STEM characterizations at FEI Company (Netherlands).

ASJC Scopus subject areas

  • General Energy
  • Environmental Chemistry
  • General Materials Science
  • General Chemical Engineering

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