Effect of controlled periodic-based illumination on the photonic efficiency of photocatalytic degradation of methyl orange.

Tokode, Oluwatosin I.; Prabhu, Radhakrishna; Lawton, Linda A.; Robertson, Peter K.J.

Abstract

The use of controlled periodic illumination with UV LEDs for enhancing photonic efficiency of photocatalytic decomposition processes in water has been investigated using methyl orange as a model compound. The impact of the length of light and dark time periods (T ON/T OFF times) on photodegradation and photonic efficiency using a UV LED-illuminated photoreactor has been studied. The results have shown an inverse dependency of the photonic efficiency on duty cycle and a very little effect on T ON or T OFF time periods, indicating no effect of rate-limiting steps through mass diffusion or adsorption/desorption in the reaction. For this reactor, the photonic efficiency under controlled periodic illumination (CPI) matches to that of continuous illumination, for the same average UV light intensities. Furthermore, under CPI conditions, the photonic efficiency is inversely related to the average UV light intensity in the reactor, in the millisecond time regime. This is the first study that has investigated the effect of controlled periodic illumination using ultra band gap UV LED light sources in the photocatalytic destruction of dye compounds using titanium dioxide. The results not only enhance the understanding of the effect of periodic illumination on photocatalytic processes but also provide a greater insight to the potential of these light sources in photocatalytic reactions.

Citation

TOKODE, O.I., PRABHU, R., LAWTON, L.A. and ROBERTSON, P.K.J. 2012. Effect of controlled periodic-based illumination on the photonic efficiency of photocatalytic degradation of methyl orange. Journal of catalysis [online], 290, pages 138-142. Available from: https://doi.org/10.1016/j.jcat.2012.03.011

• Journal Article Type: Article
• Acceptance Date: Mar 12, 2012
• Online Publication Date: Apr 21, 2012
• Publication Date: Jun 30, 2012
• Deposit Date: Feb 19, 2021
• Publicly Available Date: Mar 30, 2021
• Journal: Journal of Catalysis
• Print ISSN: 0021-9517
• Electronic ISSN: 1090-2694
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 290
• Pages: 138-142
• DOI: https://doi.org/10.1016/j.jcat.2012.03.011
• Keywords: Photocatalysis; Photonic efficiency; Titanium dioxide; UV-LED; Photoreactor; Controlled periodic illumination
• Public URL: https://rgu-repository.worktribe.com/output/1148002