Semiconductor supported by palygorskite and layered double hydroxides clays to dye discoloration in solution by a photocatalytic process. Issue 6 (December 2019)

• Record Type: Journal Article
• Authors: Morais, Alan Í.S.; Oliveira, Wemerson V.; de Oliveira, Vaeudo V.; Honorio, Luzia M.C.; Araujo, Francisca P.; Bezerra, Roosevelt D.S.; Fechine, Pierre B.A.; Viana, Bartolomeu C.; Furtini, Marcelo B.; Silva-Filho, Edson C.; Osajima, Josy A.
• Is Part Of: Journal of environmental chemical engineering. Volume 7:Issue 6(2019)
• Publication Date: 2019-12
• Subjects: Clay -- Photocatalysis -- Titanium dioxide -- Eosin yellow -- Dye; Chemical engineering -- Environmental aspects -- Periodicals; Environmental engineering -- Periodicals; Chemical engineering -- Environmental aspects; Environmental engineering; Periodicals; 660.0286
• DOI: 10.1016/j.jece.2019.103431
• Languages: English
• ISSNs: 2213-2929

Abstract

Graphical abstract: Highlights: For the first time the photocatalyst composite of (Palygorskite/layered double hydroxides) heterostructured clay was synthetized with TiO2 . The incorporation of TiO2 anatase in the materials was responsible for the photocatalytic properties. Palygorskite and layered double hydroxides show that the incorporation of TiO2 in the clays promoted the degradation of yellow eosin dye. Abstract: The present study aimed to synthesize photocatalytic materials using palygorskite (PAL) clays and a layered double hydroxide (LDH) calcined as support for titanium dioxide (TiO2 ) as an alternative for dye decontamination in aqueous media. The material was synthesized from the co-precipitation of LDH-Mg-Al in PAL and the TiO2 was incorporated using a sol-gel method. The materials were calcined at 400 °C for 2 h for formation of anatase phase of TiO2 . The samples were characterized using X-ray diffraction, Fourier Transform Infrared Spectroscopy, Thermogravimetric Analysis, Scanning Electron Microscopy and Diffuse Reflectance Spectroscopy, Specific surface area, and Photoluminescence, which proved the incorporation of TiO2 anatase in the materials, this being responsible for the photocatalytic properties. The photocatalytic activity was measured by monitoring the discoloration of the eosin yellow (EY) dye. The LDH material calcined with TiO2 (CLDHT-400) showed a discoloration rate of 99.08%. The materials made from PAL with TiO2 (PALT-400) and PAL-LDH with TiO2 (PAL-CLDH-T-400) presented discoloration rates of 75.36% and 73.19%, respectively. For all the materials, an efficient photocatalytic was proven even in the process of recycling the photocatalysts with loss of capacity of less than 7.0%, proving that the titanium dioxide remains stable in the structure of the clays. The possible photodegradation mechanism was propused based on the properties of CLDHT-400, scavenger study and the photoproducts.