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Effects of Single Metal-Ion Doping on the Visible-Light Photoreactivity of TiO_2

Choi, Jina and Park, Hyunwoong and Hoffmann, Michael R. (2010) Effects of Single Metal-Ion Doping on the Visible-Light Photoreactivity of TiO_2. Journal of Physical Chemistry C, 114 (2). pp. 783-792. ISSN 1932-7447. https://resolver.caltech.edu/CaltechAUTHORS:20100128-132221251

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Abstract

Titanium dioxide (M-TiO_2), which was doped with 13 different metal ions (i.e., silver (Ag^+), rubidium (Rb^+), nickel (Ni^(2+)), cobalt (Co^(2+)), copper (Cu^(2+)), vanadium (V^(3+)), ruthenium (Ru^(3+)), iron (Fe^(3+)), osmium (Os^(3+)), yttrium (Y^(3+)), lanthanum (La^(3+)), platinum (Pt^(4+), Pt^(2+)), and chromium (Cr3+, Cr6+)) at doping levels ranging from 0.1 to 1.0 at. %, was synthesized by standard sol−gel methods and characterized by X-ray diffraction, BET surface area measurement, SEM, and UV−vis diffuse reflectance spectroscopy. Doping with Pt(IV/II), Cr(III), V(III), and Fe(III) resulted in a lower anatase to rutile phase transformation (A−R phase transformation) temperature for the resultant TiO_2 particles, while doping with Ru(III) inhibited the A−R phase transformation. Metal-ion doping also resulted in a red shift of the photophysical response of TiO_2 that was reflected in an extended absorption in the visible region between 400 and 700 nm. In contrast, doping with Ag(I), Rb(I), Y(III), and La(III) did not result in a red shift of the absorption spectrum of TiO_2. As confirmed by elemental composition analysis by energy dispersive X-ray spectroscopy, the latter group of ions was unable to be substituted for Ti(IV) in the crystalline matrix due to their incompatible ionic radii. The photocatalytic activities of doped TiO_2 samples were quantified in terms of the photobleaching of methylene blue, the oxidation of iodide (I^(−)), and the oxidative degradation of phenol in aqueous solution both under visible-light irradiation (λ > 400 nm) and under broader-band UV−vis irradiation (λ > 320 nm). Pt- and Cr-doped TiO_2, which had relatively high percentages of rutile in the particle phase, showed significantly enhanced visible-light photocatalytic activity for all three reaction classes.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1021/jp908088x DOIArticle
http://pubs.acs.org/doi/full/10.1021/jp908088xPublisherArticle
ORCID:
AuthorORCID
Park, Hyunwoong0000-0002-4938-6907
Hoffmann, Michael R.0000-0001-6495-1946
Additional Information:© 2009 American Chemical Society. Received: August 21, 2009; Revised Manuscript Received: November 10, 2009. Publication Date (Web): December 22, 2009. gratefully acknowledge the generous support for this research that has been provided by the Northrop-Grumman Corporation. In particular, we give special credit to Dr. Ronald Pirich for his enthusiastic encouragement and intellectual support for our joint projects over the years.
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Funding AgencyGrant Number
Northrop-Grumman CorporationUNSPECIFIED
Issue or Number:2
Record Number:CaltechAUTHORS:20100128-132221251
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20100128-132221251
Official Citation:Effects of Single Metal-Ion Doping on the Visible-Light Photoreactivity of TiO2 Jina Choi, Hyunwoong Park, Michael R. Hoffmann The Journal of Physical Chemistry C 2010 114 (2), 783-792
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:17337
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:29 Jan 2010 17:13
Last Modified:09 Mar 2020 13:19

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