Selective Oxidative Degradation of Organic Pollutants by Singlet Oxygen-Mediated Photosensitization: Tin Porphyrin versus C60 Aminofullerene Systems

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• 作者：Heechan Kim ; Wooyul Kim ; Yuri Mackeyev ; Gi-Seon Lee ; Hee-Joon Kim ; Takashi Tachikawa ; Seokwon Hong ; Sanghyup Lee ; Jungbae Kim ; Lon J. Wilson ; Tetsuro Majima ; Pedro J. J. Alvarez ; Wonyong Choi ; Jaesang Lee
• 刊名：Environmental Science & Technology (ES&T)
• 出版年：2012
• 出版时间：September 4, 2012
• 年：2012
• 卷：46
• 期：17
• 页码：9606-9613
• 全文大小：418K
• 年卷期：v.46,no.17(September 4, 2012)
• ISSN：1520-5851

文摘

This study evaluates the potential application of tin porphyrin- and C₆₀ aminofullerene-derivatized silica (SnP/silica and aminoC₆₀/silica) as ¹O₂ generating systems for photochemical degradation of organic pollutants. Photosensitized ¹O₂ production with SnP/silica, which was faster than with aminoC₆₀/silica, effectively oxidized a variety of pharmaceuticals. Significant degradation of pharmaceuticals in the presence of the 400-nm UV cutoff filter corroborated visible light activation of both photosensitizers. Whereas the efficacy of aminoC₆₀/silica for ¹O₂ production drastically decreased under irradiation with 位 > 550 nm, Q-band absorption caused negligible loss of the photosensitizing activity of SnP/silica in the long wavelength region. Faster destruction of phenolates by SnP/silica and aminoC₆₀/silica under alkaline pH conditions further implicated ¹O₂ involvement in the oxidative degradation. Direct charge transfer mediated by SnP, which was inferred from nanosecond laser flash photolysis, induced significant degradation of neutral phenols under high power light irradiation. Self-sensitized destruction caused gradual activity loss of SnP/silica in reuse tests unlike aminoC₆₀/silica. The kinetic comparison of SnP/silica and TiO₂ photocatalyst in real wastewater effluents showed that photosensitized singlet oxygenation of pharmaceuticals was still efficiently achieved in the presence of background organic matters, while significant interference was observed for photocatalyzed oxidation involving non-selective OH radical.