Graduate Institute of Environmental Engineering, National Taiwan University, Taipei, 106, Taiwan, ROC.
Graduate Institute of Environmental Engineering, National Taiwan University, Taipei, 106, Taiwan, ROC; Annamacharya Institute of Technology and Sciences, Rajampeta, 516126, Kadapa, A.P., India.
J Hazard Mater. 2020 Jun 5;391:122247. doi: 10.1016/j.jhazmat.2020.122247. Epub 2020 Feb 5.
Perfluorooctanoic acid (PFOA) have been widely studied due to their persistence, bioaccumulation and possible toxic effects. In this work, we investigated a photoelectrochemical (PEC) system consisting of a graphene oxide-titanium dioxide (GOP25) anode coated on fluorine-doped tin oxide (FTO) glass for removal of PFOA in an aquatic environment. The GOP25/FTO anode was fabricated and well characterized. Nearly complete decomposition of 0.5 mg/L PFOA was achieved after 4 h of PEC treatment with an initial pH of 5.3 and a current density of 16.7 mA cm. The presence of graphene oxide (GO) on the TiO anode could enhance its electrochemical performance, thereby leading to increased decomposition efficiency. A total of 18 PFOA transformation products, including short-chain perfluoroalkyl acids, are reported in this work, and 13 products were observed for the first time. Four possible routes of PFOA decomposition, namely, decarboxylation followed by oxidation, defluorination, hydroxylation and Cl atom substitution, were determined. The presence of chlorinated byproducts in the system indicated that reactive chlorine species contributed to PFOA degradation.
全氟辛酸（PFOA）因其持久性、生物蓄积性和可能的毒性影响而受到广泛研究。在这项工作中，我们研究了一种由涂覆在掺氟氧化锡（FTO）玻璃上的氧化石墨烯-二氧化钛（GOP25）阳极组成的光电化学（PEC）系统，用于去除水环境中的 PFOA。制备并充分表征了 GOP25/FTO 阳极。在初始 pH 值为 5.3 和电流密度为 16.7 mA cm 的条件下，经过 4 h 的 PEC 处理，可实现 0.5mg/L PFOA 的完全分解。TiO 阳极上氧化石墨烯（GO）的存在可以增强其电化学性能，从而提高分解效率。在这项工作中报道了总共 18 种 PFOA 转化产物，包括短链全氟烷基酸，其中 13 种产物是首次观察到的。确定了 PFOA 分解的 4 种可能途径，即脱羧后氧化、脱氟、羟化和 Cl 原子取代。系统中存在氯化副产物表明活性氯物种有助于 PFOA 降解。
