Photocatalytic removal of phenol and methylene-blue in aqueous media using TiO2@LDH clay nanocomposites

Abstract

Please cite this article in press as: E.M. Seftel, et al., Photocatalytic removal of phenol and methylene-blue in aqueous media using TiO 2 @LDH clay nanocomposites, Catal. Today (2014), http://dx. a b s t r a c tHerein, we report the formation of a series of nanocomposites composed of LDH structures and TiO 2 with anatase crystal phase. The structure of the LDH clay was modulated by the insertion of different di-, trior tetravalent cations, such as Zn 2+ , Cu 2+ , Al 3+ , Fe 3+ or Ti 4+ , within the brucite-like sheets. Afterwards, the anatase seeds were deposited onto the LDH clays, obtaining new nanocomposite systems with tailored photocatalytic activity. In this way, the photoresponsive properties of the final nanocomposites were shifted from the UV to the visible range of the solar spectrum. The obtained nanocomposites were tested for the degradation of different organic pollutants, like phenol and methylene blue, under UV and visible light in aqueous media with different pH. The kinetic study showed that the TiO 2 @LDH nanocomposites are efficient for the phenol (and its intermediary species catechol and hydroquinone) and methylene blue photocatalytic degradation under both UV and Vis light illumination.

Graphene-oxide-supported CuAl and CoAl layered double hydroxides as enhanced catalysts for carbon-carbon coupling via Ullmann reaction

“…In particular, LDHs have been intensively investigated in recent years as catalysts and catalyst supports [4,5] in many aspects, such as organic synthesis, (photo) degradation of organic wastes, greenhouse gas control emission and H2 production [6][7][8][9][10][11][12][13].…”

Removal of crystal violet from aqueous solutions using functionalized cellulose microfibers: a beneficial use of cellulosic healthcare waste

“…It has also been widely used as a disinfectant and fungicide in aquaculture due to low cost and high effectiveness 5 . In recent years, various treatment technologies have been developed for dye removal from industrial wastewaters which are classified as chemical (ozonation 8 , chemical oxidation 9 , electrochemical 10 , photocatalytic degradation 11 ), physical (adsorption 12 , coagulation/flocculation 13 , ion exchange 14 , membrane filtration 15 ) and biological 16 treatments. The variety of synthetic dyes has been observed in effluents of some industries such as coloring, textile and tanning.…”

Chemical Composition and Reaction Mechanisms for Aged p‐Xylene Secondary Organic Aerosol in the Presence of Ammonia

“…Figure shows the UV–vis spectra of the extracts of aged p ‐xylene SOA in the absence and in presence of 20 ppm NH 3 without NO. These spectra, which have a strong absorption band at 216 nm and a weak absorption peak at 274 nm, are similar to the UV–vis spectra of the phenol solution obtained by Seftel et al . As proposed by Seftel et al ., the absorption band at 210–220 nm corresponds to the E 2 band of the benzene ring, which is due to the π→π* transition of three ethylene cyclic conjugated systems, and the absorption band at 270 nm, which is due to the overlap of the π→π* transition and the vibration of the phenol, is the characteristic absorption peak of phenol.…”

“…These spectra, which have a strong absorption band at 216 nm and a weak absorption peak at 274 nm, are similar to the UV–vis spectra of the phenol solution obtained by Seftel et al . As proposed by Seftel et al ., the absorption band at 210–220 nm corresponds to the E 2 band of the benzene ring, which is due to the π→π* transition of three ethylene cyclic conjugated systems, and the absorption band at 270 nm, which is due to the overlap of the π→π* transition and the vibration of the phenol, is the characteristic absorption peak of phenol. Compared to the absorption band at 270 nm of the phenol solution, the absorption peak at 274 nm of the extract of aged p ‐xylene SOA without NO and NH 3 is red‐shifted slightly by about 4 nm.…”