School of Civil, Environmental, and Architectural Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea.
School of Civil, Environmental, and Architectural Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea.
Chemosphere. 2021 Dec;284:131311. doi: 10.1016/j.chemosphere.2021.131311. Epub 2021 Jun 23.
Perfluorooctanoic acid (PFOA) is a carcinogen with a high binding energy between fluorine and carbon and is symmetrically linked, making it difficult to treat. In this study, a self-doped TiO nanotube array (TNTA) was used as the anode and platinum as the cathode to quantify the PFOA removal mechanism using a photoelectrochemical (PEC) system. The external voltage was negative compared to that of the anode. In addition, NO and t-BuOH were used as scavengers to quantify the PFOA oxidation/reduction mechanism in the PEC system. As a result of the study, TNTA crystals are TiO anatase, and the band gap energy was 3.42. The synergy index of PEC was 1.25, and the best electrolyte was SO. The PFOA decomposition activation energy corresponds to 70.84 kJ mol. Moreover, ΔH and ΔS correspond to 68.34 kJ mol and 0.190 kJ mol K, respectively. When the external negative voltage was 1 V, the contributions of the oxidation/reduction reaction during PFOA decomposition were 60% and 40%, and when the external negative voltage was 5 V, the contributions of the redox reaction were 45% and 55%. As the external negative voltage increased, the contribution of the reduction reaction increased as the number of electrons applied to the anode increased. When PFOA was decomposed, the by-products were CFOH, CFOH, CFOH, and CFOH, respectively. This study is expected to be used as basic data for research on the effects of other factors on the oxidation/reduction as well as the selection of anode and cathode materials on the decomposition of pollutants other than PFOA when using a PEC system.
全氟辛酸（PFOA）是一种致癌物质，氟与碳之间具有高结合能且呈对称键合，难以处理。在这项研究中，采用自掺杂 TiO 纳米管阵列（TNTA）作为阳极，铂作为阴极，通过光电化学（PEC）系统定量研究 PFOA 的去除机制。外加电压相对于阳极为负值。此外，还使用 NO 和 t-BuOH 作为清除剂来定量研究 PEC 系统中 PFOA 的氧化/还原机制。研究结果表明，TNTA 晶体为 TiO 锐钛矿，带隙能为 3.42。PEC 的协同指数为 1.25，最佳电解质为 SO。PFOA 分解的活化能对应 70.84 kJ/mol。此外，ΔH 和 ΔS 分别对应 68.34 kJ/mol 和 0.190 kJ/mol·K。当外加负电压为 1 V 时，PFOA 分解过程中氧化/还原反应的贡献分别为 60%和 40%，而当外加负电压为 5 V 时，氧化还原反应的贡献分别为 45%和 55%。随着外加负电压的增加，由于施加到阳极的电子数量增加，还原反应的贡献增加。当 PFOA 分解时，分别生成 CFOH、CFOH、CFOH 和 CFOH 等副产物。本研究有望作为在使用 PEC 系统时研究其他因素对氧化/还原的影响以及对除 PFOA 以外的污染物分解的阳极和阴极材料选择的基础数据。
