Photochemical reactivity of zinc tetraphenylporphyrin induced by nonstoichiometric CdS nanoparticles in 2-propanol
The photoreactivity of zinc tetraphenylporphyrin (ZnTPP) in the presence of photoexcited CdS nanoparticles and molecular oxygen in 2-propanol has been revisited. The photodecomposition of ZnTPP in 2-propanol, in the presence of CdS(e-CB/h+VB) and molecular oxygen, is linked to isopropyl free radical...
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| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
Wiley
2001-01-01
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| Series: | International Journal of Photoenergy |
| Online Access: | http://dx.doi.org/10.1155/S1110662X01000022 |
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| Summary: | The photoreactivity of zinc tetraphenylporphyrin (ZnTPP) in the presence of photoexcited CdS
nanoparticles and molecular oxygen in 2-propanol has been revisited. The photodecomposition of ZnTPP in
2-propanol, in the presence of CdS(e-CB/h+VB) and molecular oxygen, is linked to isopropyl free radicals
formed by both hole transfer from CdS(h+VB) to (CH3)2CHOH and the reaction of superoxide ion (O2−) with 2-propanol. Isopropyl free radicals react with ZnTPP, leading to the formation of ZnTPP•−. Intermediate
paramagnetic species monitored by EPR spectroscopy (g=2.0029,ΔH=5.7G) were characterized as superoxides
formed in the reaction of ZnTPP•− with O2. Further transformations of such EPR-active species lead
to the formation of diamagnetic intermediate photoproducts of ZnTPP observed by absorption and emission
spectroscopy. |
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| ISSN: | 1110-662X |