Potocatalytic oxidative degradation of organic pollutant with molecular oxygen activated by a novel biomimetic catalyst ZnPz(dtn-COOH)₄

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• 作者：Zehui Zhang ; Mingjian Zhang ; Jia Deng ; Kejian Deng ; ^{dengkj@scuec.edu.cn} ; Bingguan Zhang ; Kangle Lv ; Jie Sun ; Lianqing Chen
• 关键词：Zinc porphyrazine with sulfur ; Biomimetic catalyst ; Activating molecular oxygen ; Photodegradation ; Rhodamine B
• 刊名：Applied Catalysis B: Environmental
• 出版年：2013
• 出版时间：27 March, 2013
• 年：2013
• 卷：132-133
• 期：Complete
• 页码：90-97
• 全文大小：910 K

文摘

Zinc porphyrins and its analogs showing many excellent properties such as good potosensitivity, non-toxicity, high stability and facile preparation attract more and more attention of scientists. Here, a novel zinc porphyrazine, namely zinc(II) tetracarboxyl- tetra(1,4-dithiin) porphyrazine [abbreviated as ZnPz(dtn-COOH)₄] was successfully synthesized and its potocatalytic activity was studied. The ZnPz(dtn-COOH)₄ supported on an Amberlite CG-400 resin was used as a biomimetic catalyst for the activation of molecular oxygen under visible light to degrade a probe dye compound Rhodamine B (RhB) in aqueous solution. Interestingly, the mechanism for the oxidative degradation of RhB involves both ¹O₂ and HO (Type II and Type I mechanisms, respectively). More hydroxyl radicals were produced at pH 3, which was responded for the highest degradation ratio. The catalyst can be reused several times without losing its catalytic activity, with an average RhB degradation ratio around 80 % for 12 h. The most probable mechanism of RhB degradation in this study was that N,N-diehyl-N-ethyl-rhodamine was the main intermediate, which was then cleaved to small molecule by reactive oxidizing species. This study demonstrated a promising approach for the activation of molecular oxygen by the newly developed biomimetic catalyst, in which the central metal to be unchangeable valence, for environmental remediation and oxidation catalysis.