FD&C Yellow No. 5 (Tartrazine) Degradation via Reactive Oxygen Species Triggered by TiO2 and Au/TiO2 Nanoparticles Exposed to Simulated Sunlight

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• 作者：Meng Li ; Weiwei He ; Yi Liu ; Haohao Wu ; Wayne G. Wamer ; Y. Martin Lo ; Jun-Jie Yin
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2014
• 出版时间：December 10, 2014
• 年：2014
• 卷：62
• 期：49
• 页码：12052-12060
• 全文大小：443K
• ISSN：1520-5118

文摘

When exposed to light, TiO₂ nanoparticles (NPs) become photoactivated and create electron/hole pairs as well as reactive oxygen species (ROS). We examined the ROS production and degradation of a widely used azo dye, FD&C Yellow No. 5 (tartrazine), triggered by photoactivated TiO₂ NPs. Degradation was found to follow pseudo-first order reaction kinetics where the rate constant increased with TiO₂ NP concentration. Depositing Au on the surface of TiO₂ largely enhanced electron transfer and ROS generation, which consequently accelerated dye degradation. Alkaline conditions promoted ROS generation and dye degradation. Results from electron spin resonance spin-trap spectroscopy suggested that at pH 7.4, both hydroxyl radical (鈥H) and singlet oxygen (¹O₂) were responsible for dye discoloration, whereas at pH 5, the consumption of ¹O₂ became dominant. Implications for dye degradation in foods and other consumer products that contain both TiO₂ and FD&C Yellow No. 5 as ingredients are discussed.

Keywords:

TiO₂ nanoparticles; ROS; FD&C Yellow No. 5; ESR; color degradation; tartrazine