Department of Chemistry, Faculty of Science, Kanagawa University, 2946 Tsuchiya, Hiratsuka 259-1293, Japan; National Institute of Advanced Industrial Science and Technology (AIST), AIST Tsukuba West, 16-1 Onogawa, Tsukuba 305-8569, Japan.
Chemosphere. 2013 Nov;93(11):2732-7. doi: 10.1016/j.chemosphere.2013.09.024. Epub 2013 Oct 7.
Photochemical decomposition of a fluorotelomer unsaturated carboxylic acid, C3F7CFCHCOOH (1), in the presence of WO3 and an electron acceptor (S2O8(2-) or H2O2) in water under visible-light irradiation was investigated. Under an O2 atmosphere, 1 was not decomposed either by TiO2 (P25) or WO3 alone. A combination of WO3 and H2O2 also resulted in almost no decomposition of 1. In contrast, irradiation in the presence of a combination of WO3 and S2O8(2-) (potassium salt) efficiently decomposed 1 to F(-), CO2, C3F7COOH, and C2F5COOH. The decomposition of 1 was affected by the counter cation of S2O8(2-): the decomposition extent was higher with K2S2O8 than with (NH4)2S2O8. The decomposition of 1 was further enhanced when the reaction in the presence of WO3 and K2S2O8 was carried out under an argon atmosphere. Under O2, the amount of H2O2 formed in the reaction solution was an order of magnitude higher than the amount formed under argon. This fact suggests that the decrease in the decomposition of 1 under O2 can be ascribed to the formation of H2O2, which consumed S2O8(2-) and SO4(-).
在可见光照射下，研究了 WO3 和电子受体（S2O8(2-)或 H2O2）存在下，全氟丁基烯基羧酸 C3F7CFCHCOOH（1）在水中的光化学分解。在氧气气氛下，TiO2（P25）或 WO3 单独存在时 1 都不会分解。WO3 和 H2O2 的组合也几乎没有导致 1 的分解。相比之下，在 WO3 和 S2O8(2-)（钾盐）的组合存在下进行辐照，可有效将 1 分解为 F(-)、CO2、C3F7COOH 和 C2F5COOH。1 的分解受 S2O8(2-)的抗衡阳离子影响：K2S2O8 比(NH4)2S2O8 的分解程度更高。当在 WO3 和 K2S2O8 的存在下进行反应时，在氩气气氛下进行反应进一步增强了 1 的分解。在氧气下，反应溶液中形成的 H2O2 的量比在氩气下形成的量高一个数量级。这一事实表明，1 在氧气下分解减少可以归因于 H2O2 的形成，其消耗了 S2O8(2-)和 SO4(-)。
