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 |
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Hauptverfasser: | , , , , , , |
Format: | Artikel |
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. |
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ISSN: | 0304-3894 1873-3336 |
DOI: | 10.1016/j.jhazmat.2010.03.076 |