1. Preparation and characterization of bifunctional Ti–Fe kaolinite composite for Cr(VI) removal.
- Author
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Fida, Hussain, Guo, Sheng, and Zhang, Gaoke
- Subjects
- *
BIFUNCTIONAL catalysis , *TITANIUM-iron alloys , *KAOLINITE , *COMPOSITE materials , *HEXAVALENT chromium , *X-ray diffraction - Abstract
A novel bifunctional Ti–Fe kaolinite composite with excellent adsorption and photocatalytic properties was synthesized by a simple precipitation method. X-ray diffraction analysis and high-resolution transmission electron microscope analysis confirmed the existence of rutile phase TiO 2 and amorphous iron in the composite. The specific surface area of the Ti–Fe kaolinite composite is 5.5 times higher than that of the original kaolinite. The composite was used as an adsorbent as well as photocatalyst for Cr(VI) removal. The results indicate that the low pH is favorable to the Cr(VI) removal by the composite and the removal rate of Cr(VI) reached 87% at pH 3.0. Visible light irradiation obviously increased the removal of Cr(VI) by the composite and greatly shortened reaction equilibrium time, which may be attributed to the photocatalytic reduction of Cr(VI) to Cr(III) by TiO 2 associated with simultaneous redox cycle of Fe(III)/Fe(II). Various common co-existing ions did not show obvious effects on the removal of Cr(VI) by the composite. The composite exhibited very high stability for the Cr(VI) removal. The adsorption models and thermodynamics of Cr(VI) onto the composite were studied. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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