Document Details

Document Type : Article In Journal 
Document Title :
Sunlight assisted photocatalytic mineralization of nitrophenol isomers over W6+ impregnated ZnO
التحفيز الضوئى باستخدام الشمس لتعدين بديل النيتروفينول المطعم بأكسيد الزنك
 
Subject : Enviromental sciences 
Document Language : English 
Abstract : The synthesis, characterization and sunlight photocatalytic activity of W6+ impregnated ZnO for the degradation of nitrophenol isomers (2-nitrophenol, 3-nitrophenol, and 4-nitrophenol) is reported. Com-pared to pure ZnO, the impregnated catalysts exhibited a relatively improved spectral response in the visible region. The significant decrease in luminescence intensity for W6+ impregnated catalysts, relative to pure ZnO, established the effective trapping of charge carriers by surface bonded W6+ states. The char-acterization of the impregnated catalysts by FESEM, XRD and XPS revealed the presence of impregnated W6+ entities at the surface without affecting the morphology of ZnO. The synthesized catalysts exhibited superior activity for the mineralization of three nitrophenol isomers under sunlight exposure. Based on HPLC analysis, ∼99% of 2- and 4-nitrophenol was degraded in a short span of 120 min while a degrada-tion of >80% was observed in 3-nitrophenol in the same period. Time scale TOC measurements ratified the mineralization capability of impregnated catalysts. The release of NO2−, NO3− ions in the solution, pH measurements and non-existence of hydroxylated aromatic intermediates revealed that superoxide anion radicals (O2•−) are the major contributors in the degradation process. Besides the traces of coupling products, major intermediates identified by GC–MS analysis were either aliphatic dihydroxy alcohols, car-boxylic acids or other oxygen containing species depicting that the degradation process proceeds through ring opening mechanism. The W6+ impregnated catalyst also furnished high activity in the visible portion of sunlight. Suitable kinetic models were applied to estimate the rate constants (k) of various processes involved in the degradation process. The stability of the photocatalyst against photocorrosion and the possible decrease in the activity of the catalyst in the successive use was also monitored. 
ISSN : 0926-3373 
Journal Name : Applied Catalysis B: Environmental 
Volume : 160 
Issue Number : 1 
Publishing Year : 1435 AH
2014 AD 
Article Type : Article 
Added Date : Monday, August 4, 2014 

Researchers

Researcher Name (Arabic)Researcher Name (English)Researcher TypeDr GradeEmail
A. HameedHameed, A. Researcher  
M. AslamAslam, M. Researcher  
Iqbal M.I. IsmailIsmail, Iqbal M.I.Researcher  
S. ChandrasekaranChandrasekaran, S. Researcher magondal@kfupm.edu.sa
M.W. KadiKadi, M.W. Researcher  
M.A. GondalGondal, M.A. Researcher magondal@kfupm.edu.sa

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