Visible Light Photo-oxidation of Model Pollutants Using CaCu<sub>3</sub>Ti<sub>4</sub>O<sub>12</sub>: An Experimental and Theoretical Study of Optical Properties, Electronic Structure, and Selectivity



Clark, Joanna H, Dyer, Matthew S ORCID: 0000-0002-4923-3003, Palgrave, Robert G, Ireland, Christopher P, Darwent, James R, Claridge, John B ORCID: 0000-0003-4849-6714 and Rosseinsky, Matthew J ORCID: 0000-0002-1910-2483
(2011) Visible Light Photo-oxidation of Model Pollutants Using CaCu<sub>3</sub>Ti<sub>4</sub>O<sub>12</sub>: An Experimental and Theoretical Study of Optical Properties, Electronic Structure, and Selectivity. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 133 (4). pp. 1016-1032.

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Abstract

Charge transfer between metal ions occupying distinct crystallographic sublattices in an ordered material is a strategy to confer visible light absorption on complex oxides to generate potentially catalytically active electron and hole charge carriers. CaCu3Ti4O12 has distinct octahedral Ti4+ and square planar Cu2+ sites and is thus a candidate material for this approach. The sol−gel synthesis of high surface area CaCu3Ti4O12 and investigation of its optical absorption and photocatalytic reactivity with model pollutants are reported. Two gaps of 2.21 and 1.39 eV are observed in the visible region. These absorptions are explained by LSDA+U electronic structure calculations, including electron correlation on the Cu sites, as arising from transitions from a Cu-hybridized O 2p-derived valence band to localized empty states on Cu (attributed to the isolation of CuO4 units within the structure of CaCu3Ti4O12) and to a Ti-based conduction band. The resulting charge carriers produce selective visible light photodegradation of 4-chlorophenol (monitored by mass spectrometry) by Pt-loaded CaCu3Ti4O12 which is attributed to the chemical nature of the photogenerated charge carriers and has a quantum yield comparable with commercial visible light photocatalysts.

Item Type: Article
Additional Information: ## TULIP Type: Articles/Papers (Journal) ##
Uncontrolled Keywords: CHEMICAL NATURE, COMPLEX OXIDES, OPTICAL ABSORPTION, PHOTOCATALYSIS, POLLUTION, ELECTRONIC STRUCTURE CALCULATIONS, SUB-LATTICES, MASS SPECTROMETRY, METAL IONS
Subjects: ?? QD ??
Divisions: Faculty of Science and Engineering > School of Physical Sciences
Depositing User: Symplectic Admin
Date Deposited: 17 Nov 2011 14:12
Last Modified: 14 Oct 2023 04:56
DOI: 10.1021/ja1090832
Publisher's Statement : © 2010 American Chemical Society
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/4555