Study on the mechanism of photo-degradation of p-nitrophenol exposed to 254 nm UV light

The degradation mechanism of p-nitrophenol (p-NP) exposed to 254 nm UV light was studied in the presence and the absence of oxygen respectively via both steady-state photolysis and time-resolved laser flash photolysis (LFP) experiments. It has been confirmed that p-NP can be photo-ionized to produce...

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Veröffentlicht in:Journal of hazardous materials 2010-08, Vol.180 (1), p.86-90
Hauptverfasser: Zhao, Sufang, Ma, Hongjuan, Wang, Min, Cao, Changqing, Xiong, Jie, Xu, Yunshu, Yao, Side
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Sprache:eng
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Zusammenfassung:The degradation mechanism of p-nitrophenol (p-NP) exposed to 254 nm UV light was studied in the presence and the absence of oxygen respectively via both steady-state photolysis and time-resolved laser flash photolysis (LFP) experiments. It has been confirmed that p-NP can be photo-ionized to produce its radical cation (p-NP + ) and hydrated electron (e aq −) with a quantum yield of 0.52. In neutral solution p-NP + will be quickly deprotonated to form its phenoxyl radical (p-NP ) which will react with oxygen to promote the breakage of benzene ring of p-NP. The degradation efficiency of p-NP exposed to 254 nm UV is as low as commonly reported. However, oxygen could improve the photo-degradation efficiency, which is due to the reaction of oxygen with p-NP . The reaction between oxygen and p-NP has been experimentally confirmed both in LFP and in pulse radiolysis.
ISSN:0304-3894
1873-3336
DOI:10.1016/j.jhazmat.2010.03.076