Colloidal nanocrystal films as catalysts for environmental applications

Author(s): Roberto Comparelli, Anna Panniello, Michela Corricelli, Elisabetta Fanizza, Marinella Striccoli, Vito Locaputo, Giuseppe Mascolo, Angela Agostiano, M. Lucia Curri
Paper category : conference
Book title: International RILEM Symposium on Photocatalysis, Environment and Construction Materials - TDP 2007
Editor(s): P. Baglioni and L. Casssar
Print-ISBN: 978-2-35158-056-1
e-ISBN: 978-2-35158-057-8
Publisher: RILEM Publications SARL
Publication year: 2007
Pages: 259 - 266
Total Pages: 8
Language: English

Abstract: The photocatalytic degradation of organic pollutants assisted by semiconductors represent one of the most attractive techniques among the Advanced Oxidation Processes (AOPs).
Anatase TiO2 is at the moment the most utilised photocatalyst, and coupled semiconductor photocatalysts can provide an interesting way to enhance the efficiency of a photocatalytic process by increasing the charge separation, and extending the energy range of photoexcitation for the system.
Nanosized materials are expected to have a beneficial behaviour on the catalytic properties, in terms of active sites and size dependent red-ox properties, thus paying off the detrimental effect due to the semiconductor immobilization onto substrates.
In this paper, anatase TiO2 colloidal nanorods (NRs), noble metal-semiconductor heterostructures (TiO2-NR/Ag) and coupled nanocrystalline semiconductor system (CdS NCs/TiO2 NRs) have deposited onto suitable substrates and tested under UV and visible irradiation for the degradation of an azo dye, Methyl Red, and a pesticide, Carbofuran, respectively, in aqueous environment. The experiments have been monitored by absorption and HPLC-MS measurements. The obtained results show that the colloidal nanocrystalline oxides present higher photoactivity than their commercial counterparts and the coupled system, the original TiO2-NR/Ag based catalysts have shown higher photoactivity then the bare TiO2 NRs and a scarce dependence on pH conditions. In the case of the CdS NCs/TiO2 NRs, the photoresponse of TiO2 NCs under solar light irradiation has been sensibly increased by the presence of CdS NCs.

Online publication: 2011-07-01
Publication type : full_text
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