کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1405063 | 1501707 | 2016 | 9 صفحه PDF | دانلود رایگان |
• Photocatalytic activity of Keggin-type polyoxometalates can be tuned by the transition metal substitution.
• Introduction of transition metal ion leads to an increase in the degradation of MG.
• A moderate decrease of oxidizing ability of catalyst may improve the photocatalytic activity.
• The reaction pathways about the photocatalytic oxidative of MG molecule were proposed.
In the present paper, Keggin-type polyoxometalates (POMs) (NH4)3[PW12O40] and its mono-transition-metal-substituted species (NH4)5[{PW11O39}MII(H2O)] (M = Mn, Fe, Co, Ni, Cu, Zn) have been synthesized and used as photocatalyst to activate O2 for the degradation of dye molecule under visible-light irradiation. Because of the strong adsorption on the surface of POM catalyst, malachite green (MG) molecule was employed as a molecular probe to test their photocatalytic activity. The photodegradation study shows that introduction of transition metal ion leads to an increase in the degradation of MG in the following order: Mn < Fe < Co < [PW12O40]3− < Ni < Cu < Zn, which indicates that the photocatalytic activity of these POMs is sensitive to the transition metal substituted effects. Electronic structure analysis based on the density functional theory calculations shows that a moderate decrease of oxidizing ability of POM catalyst may improve the photocatalytic activity in the degradation of dye molecule under visible-light irradiation. Meanwhile, intermediate products about the photocatalytic oxidation of MG molecule were proposed on the basis of gas chromatograph mass spectrometer analysis.
The Keggin-type polyoxometalate salt (NH4)3[PW12O40] and its mono-transition-metal-substituted species (NH4)5[{PW11O39}MII(H2O)] (M = Mn, Fe, Co, Ni, Cu, Zn) have been used as photocatalyst to activate O2 for the degradation of dye molecules under visible-light irradiation.Figure optionsDownload as PowerPoint slide
Journal: Journal of Molecular Structure - Volume 1110, 15 April 2016, Pages 44–52