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Photodegradation of phenol using reconstructed Ce doped Zn/Al layered double hydroxides as photocatalysts

Paper ID Volume ID Publish Year Pages File Format Full-Text
53536 46973 2016 7 PDF Available
Title
Photodegradation of phenol using reconstructed Ce doped Zn/Al layered double hydroxides as photocatalysts
Abstract

•Ce was incorporated to ZnAl LDH by coprecipitation in a single step.•A distortion of the atomic planes in the direction [1 1 0] is produce by Ce ions.•XPS study confirms the co-existence of Ce4+ and Ce3+ species.•Ce4+ acts as a trap of the photogenerated electron, decreasing the recombination.•The maximum content of Ce for an optimal photocatalytic behavior is 5%.

ZnAlCe layered double hydroxides (LDH) with different content of Ce (3.5, 5.0 and 10.0% mol) were successfully synthesized in one step by the co-precipitation technique. The partial incorporation of cerium into the layers of the material can be appreciated in the XRD diffraction patterns, showing some deformation in the crystallographic direction (1 1 0) of the ZnAlCe LDHs. In the samples calcined at 400 °C, the UV–vis-DRS study showed a shift of the absorption edge toward the blue region of the spectra as a result of the cerium incorporation to the ZnAl LDH; the analysis of XPS confirms the co-existence of Ce4+ and Ce3+ in the ZnAlCe LDHs. The photodegradation and mineralization of phenol under UV irradiation was remarkably improved in the sample containing 5% mol of Ce. A mechanism where cerium in the layered material promotes the separation of the photogenerated electron–hole pairs is proposed. In this mechanism, Ce4+ acts as electron scavenger, facilitating the electron transfer toward adsorbed O2 and an accumulation of holes, increasing the generation of radicals OH.

Graphical abstractA distortion of the atomic planes in the direction [1 1 0] appears with the presence of Ce in ZnAlCe LDHs. A proposed mechanism explains the role of Ce4+ in ZnAlCe LDHs, acting as a photogenerated electron (e−) scavenger and producing an accumulation of photogenerated holes (h+), which may help the OH radicals generation.Figure optionsDownload full-size imageDownload high-quality image (160 K)Download as PowerPoint slide

Keywords
Layered double hydroxides; Ce-doped ZnAl LDH; LDH photocatalysts; Ce oxidation states; Phenol photodegradation; Electron–hole pair separation
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Photodegradation of phenol using reconstructed Ce doped Zn/Al layered double hydroxides as photocatalysts
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Publisher
Database: Elsevier - ScienceDirect
Journal: Catalysis Today - Volume 271, 1 August 2016, Pages 213–219
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Catalysis
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us