Photocatalytic decolorization of methylene blue in the presence of TiO2/ZnS nanocomposites

authors	Franco, A; Neves, MC; Carrott, MMLR; Mendonca, MH; Pereira, MI; Monteiro, OC
nationality	International
journal	JOURNAL OF HAZARDOUS MATERIALS
author keywords	TiO2; Methylene blue; Decolorization; Photocatalysis; TiO2/ZnS nanocomposites
keywords	DECOMPOSITION; NANOPARTICLES; DEGRADATION; PHOTODEGRADATION; PRECURSORS; SPHERES; DYES
abstract	The synthesis of distinct nanocrystalline TiO2 capped ZnS samples was carried out using a chemical deposition method. The materials characterization showed that the presence of ZnS onto TiO2 surface results in a red shift of the material band edge when compared with the initial semiconductor The photocatalytic activity of the prepared nanocomposites was tested on the decolorization of methylene blue (MB) aqueous solutions. The dye photodecolorization process was studied considering the influence of experimental parameters such as catalyst concentration, TiO2/ZnS ratio, pH and methylene blue adsorption rate. The material with the best catalytic activity towards the methylene blue photodecolorization was the TiO2 doped with 0.2% of ZnS. The complete photodecolorization of a 20 ppm methylene blue Solution, at natural pH was achieved in less than 20 min, nearly 70 min faster than the TiO2 photoassisted process. (C) 2008 Elsevier B.V. All rights reserved.
publisher	ELSEVIER SCIENCE BV
issn	0304-3894
year published	2009
volume	161
issue	1
beginning page	545
ending page	550
digital object identifier (doi)	10.1016/j.jhazmat.2008.03.133
web of science category	Engineering, Environmental; Engineering, Civil; Environmental Sciences
subject category	Engineering; Environmental Sciences & Ecology
unique article identifier	WOS:000262328000075