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|Title: ||Photocatalytic degradation of methylparathion - An endocrine disruptor by Bi³⁺-doped TiO₂|
|Authors: ||Rengaraj, S.|
Tanner, Peter A.
Fan, Z. F.
Pang, Geoffrey Kin-hung
|Issue Date: ||16-Mar-2006 |
|Citation: ||Journal of molecular catalysis A: Chemical, 16 Mar. 2006, v. 247, no. 1-2, p. 36-43.|
|Abstract: ||The relationships between the catalyst physicochemical properties and its photocatalytic activity have been investigated and elucidated in
the photodegradation of the organophosphate insecticide methylparathion. The photocatalytic degradation was investigated by using a sol–gel
synthesized Bi³⁺-doped TiO₂nanocatalyst (using doping concentrations up to 2 wt.% Bi³⁺) under UV-A light in aqueous suspension. The prepared
photocatalysts were characterized by X-ray diffraction, (environmental) scanning electron microscopy, transmission electron microscopy,
energy dispersive X-ray analysis, IR–UV–vis absorption spectra, X-ray photoelectron emission spectroscopy and room- and low-temperature
photoluminescence spectra. The photodegradation and mineralization products of methylparathion were analyzed by high performance liquid
chromatography, dissolved organic carbon and ion chromatography techniques. The experiments demonstrated that the presence of Bi³⁺ in TiO₂catalysts substantially enhances the photocatalytic degradation of methylparathion in aqueous suspension. The degradation of methylparathion by
these catalysts followed a first-order kinetic model and an optimal dosage between 0.7 and 1.5% Bi³⁺ in TiO₂achieved the fastest methylparathion
degradation under the experimental conditions. This study has also investigated the mineralization of methylparathion in terms of carbon, sulphur
and nitrogen conversion during the photocatalytic reaction. The possible mechanisms of photoluminescence quenching and photodegradation are
elucidated in the context of donor–acceptor interactions with Bi–O polyhedra acting as electron trapping centres which hinder electron–hole pair
|Description: ||DOI: 10.1016/j.molcata.2005.11.030|
|Rights: ||Journal of Molecular Catalysis A: Chemical © 2005 Elsevier B. V. The journal web site is located at http://www.sciencedirect.com.|
|Type: ||Journal/Magazine Article|
|Appears in Collections:||CEE Journal/Magazine Articles|
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