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A comparison of several nanoscale photocatalysts in the degradation of a common pollutant using LEDs and conventional UV light

TitleA comparison of several nanoscale photocatalysts in the degradation of a common pollutant using LEDs and conventional UV light
Publication TypeJournal Article
Year of Publication2009
AuthorsGhosh, JP, Sui, R, Langford, CH, Achari, G, Berlinguette, CP
JournalWATER RESEARCH
Volume43
Pagination4499-4506
Date PublishedOCT
ISSN0043-1354
Abstract

A comparative study on the photocatalytic activities of four different catalysts, P-25 TiO(2), TiO(2) nanofibers, tin-doped TiO(2) nanofibers under UV light irradiation at 350 nm, and coumarin (C-343) coated TiO(2) nanofibers at 436 nm light emitting diodes (LED) is reported. Catalysts performance has been compared based on their reflectance spectrum and activity. A common water contaminant 4-chlorophenol was used as a substrate to compare the activity of the different catalysts under both direct and dye sensitized conditions. Results indicated that amongst the four different catalysts the activity of P-25 was the highest. However the activity of C-343 coated TiO(2) nanofibers in the LED (436 nm) based reactor was competitive. identification of reaction intermediates implied that the reaction pathways under UV (band gap) and visible (dye sensitized) irradiation were different. Nonetheless, ring opening took place in all reactions with both maleic and dihydroxymaleic have been identified as intermediates. The study indicates that ordered arrays of TiO(2) irradiated by panels of arrays of low cost high intensity LEDs might be used for the design of reactors. The near monochromaticity, long life, and operation under direct currents are advantages of using LEDs. (C) 2009 Elsevier Ltd. All rights reserved.

DOI10.1016/j.watres.2009.07.027