Layered Double Hydroxides as Highly Efficient Photocatalysts for Visible Light Oxygen Generation from Water

• Type: Article in International Scientific Journal
• Date: 2009

Authors

Claudia G Gomes Silva (Author) FEUP; Younes Bouizi (Author) Other; Vicente Fornes (Author) Other; Hermenegildo Garcia (Author) Other

Journal

Title: Journal of the American Chemical Society

Vol. 131

Pages: 13833-13839

ISSN: 0002-7863

Publisher: American Chemical Society

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ISI Web of Knowledge - 329 Citations

ISI Web of Science

Scopus - 411 Citations

COMPENDEX

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-008-NPQ

DOI: 10.1021/ja905467v

Abstract (EN): Oxygen generation through photocatalytic water splitting under visible light irradiation is a challenging process. In this work we have synthesized a series of Zn/Ti, Zn/Ce, and Zn/Cr layered double hydroxides (LDH) at different Zn/metal atomic ratio (from 4:2 to 4:0.25) and tested them for the visible light photocatalytic oxygen generation. The most active material was found to be (Zn/Cr)LDH with an atomic ratio of 4:2 that exhibits two absorption bands in the visible region at lambda(max) of 410 and 570 nm. It was found that the efficiency of these chromium layered double oxides for oxygen generation increases asymptotically with the Cr content. Using iron oxalate as chemical actinometer we have determined that the apparent quantum yields for oxygen generation (Phi(apparent) = 4 x mol oxygen/mol incident photons) are of 60.9% and 12.2% at 410 and 570 nm, respectively. These quantum yields are among the highest values ever determined with visible light for solid materials in the absence of light harvesting dye. The overall efficiency of (Zn/Cr)LDH for visible light oxygen generation was found to be 1.6 times higher than that Of WO3 under the same conditions.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7