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全氟和多氟烷基物质(per/polyfluorinated alkyl substances,PFASs)因其热稳定性和化学惰性,在厨具、纺织、皮革、农药和消防等生产生活过程中具有广泛应用[1-3]. 同样,正因为PFASs独特的稳定性,其环境持留性和生物毒性近年来备受关注. 全氟烷基酸(perfluoroalkyl acid,PFAAs)是PFASs的一个子类,其所有的碳氢键(C—H)都被碳氟键(C—F)取代,其中全氟辛基羧酸(perfluorooctanoic acid,PFOA)和全氟辛基烷磺酸(perfluorooctane sulfonates,PFOS)是两种最典型的PFAAs(表1为PFOA和PFOS的结构和物理化学性质). 据最近的研究估计,每年大约有23—506 t PFOA和42—810 t PFOS被排放入大气,而每年沉积到陆地环境的PFOA和PFOS分别为1—13 t以及1—20 t[4]. 另有研究表明,全球PFAAs的累计排放量至少为4.6万t,其中很大一部分被直接排放到环境水体中[5]. 2000年以来,通过部分国家和企业的自愿行为,长链PFAAs(≥C7)的产量已大为减少[6],但中短链PFAAs在工业领域的应用仍未有明确限制. PFAAs的大规模使用造成其在全球环境中的普遍污染,其中水体是其重要环境归宿,并可能最终影响饮用水安全. 最近的一项研究表明,我国许多城市和地区的饮用水都受到了不同程度的PFAAs污染,而PFOA和PFOS是饮用水中残留最主要的两类PFAAs. 不同城市污染特征不同,杭州和自贡主要为PFOA,浓度分别高达115.40 ng·L−1和467.96 ng·L−1,而连云港的饮用水中PFOS的浓度高达186.17 ng·L−1[7-8],均高于2016年美国环境保护署建议的饮用水中PFOA和PFOS的健康指南阈值(70 ng·L−1)[9]. 大多数PFAAs具有较强的生物蓄积性,进入生物体后分布于肝脏以及血清内,可能对生物体产生各种潜在危害[10-14],研究发现,多种急性或慢性人类疾病,如甲状腺疾病、哮喘、焦虑、肥胖、儿童过敏、高尿酸血症、过氧化物酶体增殖、免疫毒性、肾脏疾病、肝损害和心血管疾病,都可能与PFAAs暴露有关[15-16]. 世界卫生组织国际癌症研究所于2014年6月发布的《关于人类致癌风险的专题报告》将PFOA类物质划分为2B类(人类可疑致癌物).
水环境中PFAAs的去除效果影响生态安全和人群健康,已成为近年研究的热点. 对水环境中PFAAs的去除技术主要包括物理分离和化学降解. 其中吸附和过滤等物理分离技术仅能将PFAAs从水相中转移,而未破坏其分子结构,不能有效降低PFAAs环境风险. 目前更多的研究关注通过不同技术手段断裂C—F键,最终达到矿化和彻底脱除PFAAs环境毒性的目的. 由于氟的强电负性(E0(F/F−) =3.6 V)[17],以及氟原子和碳原子的紧密键合,使得C—F键具有极高的化学键能(116 kcal·mol−1)[18],其次,3个未成对的氟离子可以形成保护性外壳,使中心碳原子极难与亲核物质反应[19],以上PFAAs特殊的化学结构,使PFAAs对化学和热破坏表现较高稳定性,可以抵抗大多数降解技术的破坏[20]. 高级氧化技术能够产生各种自由基强氧化剂,被认为是处理难降解有机污染物的有效手段,其中光催化氧化和电催化氧化因其处理过程高效、低成本和环境友好等特点,在PFAAs降解应用的前途最被关注[21].
激发光降解催化剂的光能量,光生活性基团的种类和产率以及催化反应活性的位点是影响PFAAs光降解效率的主要因素,也是研究者们开发PFAAs光催化材料,提高其催化降解效率的关键落脚点. 元素掺杂、构筑异质结、金属沉积、材料复合以及形貌调控等是科学家选择改性催化材料,提升光催化性能最常用的技术手段. 对于电催化氧化技术而言,面临高能耗、阳极腐蚀、析氧副反应竞争等问题,对电极进行三维化、引入中间层和金属负载的改性方法,以增加电催化活性,延长电极寿命,提高析氧过电位等成为提高电催化氧化PFAAs性能研究的热点. 除此之外,研究者们还探索了通过超声/辐射辅助、阴阳电极协同以及多自由基反应扩展降解路径等多重技术协同的方法,进一步提高PFAAs的降解效率.
本文就近5年来(2016—2021年),针对PFOA和PFOS两类典型PFAAs的光催化和电催化氧化降解的研究进展进行了文献调研,综述了两种高级氧化技术在降解水环境中PFAAs过程的机理和关键影响因素,分别分析了现有提高两种技术氧化降解效率的技术方法和原理,并对其可行的发展方向进行了初步展望,以期为今后PFAAs处理处置技术研究提供有益参考.
典型全氟烷基酸的光/电催化降解:性能提升策略与反应机制
Photocatalytic and electrocatalytic degradation of typical perfluoroalkyl acids: Performance improvement strategies and reaction mechanisms
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摘要: 全氟烷基酸(perfluoroalkyl acids,PFAAs)在全球水体中普遍存在,且对生物体和人体均具有潜在毒害作用,是近年来被广泛关注的主要污染物之一. 水环境中PFAAs的去除和降解是降低其生态健康风险的重要手段,也是目前研究的焦点之一. PFAAs分子中所有C—H键均被C—F键取代,特殊的结构使PFAAs具有极高的化学稳定性,常规的氧化技术难以实现水环境中PFAAs的有效降解. 光催化氧化和电催化氧化是目前处理难降解有机污染物的两种主要高级氧化技术,也是研究水环境中PFAAs降解去除的主流关键技术. 以全氟辛基羧酸(perfluorooctanoic acid,PFOA)和全氟辛基磺酸(perfluorooctane sulfonates,PFOS)为研究PFAAs降解的两类典型代表,本文综述了近年来光催化氧化和电催化氧化两种技术在水相PFOA和PFOS降解研究的文献报道,对提高PFAAs降解效率所采用的主要技术改进策略及其背后的理论机制进行了梳理和总结. 基于提高催化反应活性物质产率,增加活性反应位点和反应物传质效率以及提高反应体系稳定性等优化策略,对光催化中催化剂和电催化中电极材料的优选,通过元素掺杂、异质结构筑、金属沉积、材料复合、形貌调控等对材料进行特定功能化改性,以及向反应体系添加氧化物种前驱体、多技术耦合等协同改进方法,两类PFAAs的氧化降解效率显著提高. 光/电催化氧化对水中PFAAs的去除率、脱氟率和矿化率(中位值)分别达到91%和98%、38%和76%、65%和81%,展现了这两种高级氧化技术在PFAAs降解中优越的性能和应用前景. 结合两种高级氧化技术进展,展望其在PFAAs降解研究的发展方向,以期为今后PFAAs的污染控制技术研究提供有益参考.Abstract: Perfluorinated alkyl acids (PFAAs), a group of widely concerned pollutants in recent years, are widespread in water bodies around the world and are potentially toxic to both organisms and humans. The degradation and removal of PFAAs in aqueous environment are crucial means to reduce their ecological and health risks, and are also focuses of current research. PFAAs show extremely chemical stability due to all C—H bonds being replaced by C—F bonds, which makes it difficult to achieve effective degradation of PFAAs by conventional oxidation techniques. Photocatalytic oxidation and electrocatalytic oxidation are two main advanced oxidation techniques for the treatment of refractory organic pollutants and already become the key techniques for the degradation and removal researches of PFAAs in the aqueous environment. With perfluorooctanoic acid (PFOA) and perfluorooctane sulfonates (PFOS) been selected as the two typical representatives, we reviewed the literature reports on the degradation of PFAAs in the aqueous phase by photocatalytic oxidation and electrocatalytic oxidation in recent years. And the main technical improvement strategies and the underlying theoretical mechanism to improve the degradation efficiency were summarized. The main optimization strategies adopted in literature works including improving the yield of active groups in the catalytic reaction, increasing the active reaction sites and mass transfer efficiency of reactants, and improving the stability of the reaction system. Specific functional modifications such as element doping, heterostructure construction, metal deposition, material composition and morphology control, were carried out to optimize the catalysts in photocatalysis and the electrode in electrocatalysis. Several synergistic methods such as adjunction of active oxide precursors and multi-technology coupling were also applied to accomplishing significant improvements of oxidation degradation efficiency of the two types of PFAAs. The removal rate, defluorination rate, and mineralization rate (median) of PFOA and PFOS in water by photocatalytic/electrocatalytic oxidation reached 91% and 98%, 38% and 76%, and 65% and 81%, respectively, demonstrating the superior performance and application prospects of these two advanced oxidation techniques in the degradation of PFAAs. Finally, based on the progress in the two advanced oxidation technologies, development directions of PFAAs degradation research were prospected. We hope this review will help in the pollution control researches of PFAAs in future.
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表 1 PFOA和PFOS的结构和物理化学性质
Table 1. Structure and physicochemical properties of PFOA and PFOS
化合物
Compounds分子式
Molecular formula化合物结构
Chemical structures分子量
Molecular weight酸度系数
pKa沸点/℃
Boiling point熔点/℃
Melting pointPFOA C7F15COOH 414.07 0.5 40—50 189—192 PFOS C8F17SO3H 500.13 -3.27 >400 133 表 2 不同改进策略的PFAAs光催化降解反应效率
Table 2. Photocatalytic degradation reaction efficiency of PFAAs with different improved strategies
化合物
Compounds浓度
Concentration降解条件
Degradation conditions降解率/%
Degradation脱氟率/%
Defluorination矿化率/%
Mineralization中间产物
Intermediate
products参考文献
ReferencesPFOS 0.1 mg·L−1 TiO2, CTiO2=1.45g·L−1,
pH=4, 25 ℃, 8 h, UV83% — — C7HF15O3S
C7H5F11O2S
C6H3F11O2S[23] 0.1 mg·L−1 2% Ga/TNTs@AC, pH=7,4 h, UV,
电流强度=210 W·m−275% — 66.2% C4—C8 PFCAs [39] PFOA 100 μmol·L−1 In2O3, 254 nm, 4 h 80% — — C2—C7 PFCAs [24] 40 mg·L−1 Bi/BiOI0.8F0.2, UV–vis 100%(2 h) 10%(3 h) 19%(2 h) C5—C7 PFCAs [26] 1 mg·L−1 0.5 g·L−1 Bi5O7I/ZnO, 6 h,
pH=4, 420 nm91% — — C4—C7 PFCAs [28] 10 mg·L−1 0.25 g·L−1 Sb2O3/TiO2, 2 h, UV 81.7% — — — [29] 0.5 mmol·L−1 2.0 g·L−1 Sm-Fe, 185 nm, 2 h 48.61% — — C5—C7 PFCAs [30] 50 mg·L−1 MIP-Ag/TiO2NTs-UV, 23 W,
254 nm, 8 h91% — — C3—C7 PFCAs [31] 0.3 mmol·L−1 3DSG-TiO2QD,UV,10 h 91% — — C4—C7 PFCAs [32] 20 mg·L−1 0.5 g·L−1 In-Ga2O3, UV,
pH=4.5, 25 ℃100%(1 h) 57%(4 h) — C3—C7 PFCAs [33] 50 mg·L−1 0.25 g·L−1 TiO2, 0.75 g·L−1 PMS,
400—770 nm, pH=3, 8 h100% — — C5—C7 PFCAs [35] 10 mg·L−1 0.2 g ZnO nanorods, 50 mg·h−1 O3,
254 nm, pH=3, 4 h70.5% — — C2—C7 PFCAs [36] 10 mg·L−1 0.2 g 0.6%-ZnO-rGO, 50 mg·h−1 O3,
254 nm, 100 mg·L−1 S2O82-, 4 h99.2% — — C4—C7 PFCAs [37] 10 mg·L−1 In2O3-400, UV ~100%(4 h) 38%(8 h) — C5—C7 PFCAs [38] 0.2 mg·L−1 1.0 g·L−1 BiOHP/CS, pH=7,
254 nm, 21 mW·cm−290%(1 h) 32.5%(4 h) — C2—C7 PFCAs [41] 10 mg·L−1 40 mg In2O3纳米棒和纳米球,
254 nm, 8 h100% — 75–80% C5—C7 PFCAs [42] 10 mg·L−1 12 mg BiOI0.95Br0.05, UV 96%(2 h) — 65%(3 h) C4—C7 PFCAs [43] 0.1 mg·L−1 1g·L−1 Fe/TNTs@AC,
21 mW·cm−2, 254 nm, 4 h90% 62% — C2—C7 PFCAs [44] 表 3 不同改进策略的PFAAs电催化氧化降解反应效率
Table 3. Electrocatalytic oxidation degradation reaction efficiency of PFAAs with different improved strategies
化合物
Compounds浓度
Concentration降解条件
Degradation conditions降解率/%
Degradation脱氟率/%
Defluorination矿化率/%
Mineralization中间产物
Intermediate
products参考文献
ReferencesPFOS 100 mg·L−1 Ti/Sn-Sb/SnO2-F-Sb, pH=3,
10 mmol·L−1 NaClO4, 20 mA·cm−2, 2 h99% 87.1% 65.7% C2—C8 PFCAs [51] 0.1 mmol·L−1 Ti4O7, 3.9—3.7 V vs.SCE, 3 h 93.1% 80.9% 90.3% PFHpS
PFHxS[58] 2.0 μmol·L−1 Ti4O7 REM, 3.15 V,
100 mmol·L−1 Na2SO498.3%(2 h) — 72%(2.5 h) C4—C8 PFCAs [59] 50 mg·L−1 Ti/TiO2-NTs/Ag2O/PbO2, 3 h,
30 mA·cm−2, 1.4 g·L−1 NaClO474.87%, 11.49% — C4—C8 PFCAs [61] 50 mg·L−1 3DG-PbO2, 0.05 mol·L−1 Na2SO4,
30 mA·cm−2, pH=7, 2 h96.17% 68.5% — C2—C8 PFCAs [62] PFOA 20 mg·L−1 陶瓷/PbO2-PTFE, 15 mA·cm−2,
pH=7, 15 mmol·L−1 Na2SO4, 5 h98.9% 52.5% 80.7% C4—C7 PFCAs [53] 120 μmol·L−1 BDD为阳极,Fe10MnC为阴极, 4 h 97% — 93% C2—C7 PFCAs [54] 0.1 mmol·L−1 Ti4O7,10 mA·cm−2,硫酸盐, pH=6.9, 2 h 97.1% 61.4% — — [55] 50 mg·L−1 BND, 4.0 mA·cm−2, 0.05 mol·L−1
Na2SO499.3%(1.5 h) 76.8%(3 h) 77.4%(3 h) C2—C7 PFCAs [56] 0.12 mmol·L−1 Pd-Ti4O7, 10 mA·cm−2, 1 h,
50 mmol·L−1 Na2SO4, 25 ℃,86.7% 77.9% 81.3% C4—C7 PFCAs [60] 50 mg·L−1 Ti3+/TiO2-NTA, 2 mA·cm−2, 1.5 h 98.1% 74.8% 93.3% C2—C7 PFCAs [63] 60 mg·L−1 Ti/SnO2-Sb/Ce-PbO2, 52 W,
20 kHz, 15 mA·cm−2, 3 h~100% 87.9% — C2—C7 PFCAs [64] -
[1] WANG T Y, WANG P, MENG J, et al. A review of sources, multimedia distribution and health risks of perfluoroalkyl acids (PFAAs) in China [J]. Chemosphere, 2015, 129: 87-99. doi: 10.1016/j.chemosphere.2014.09.021 [2] SCHULTZ M M, BAROFSKY D F, FIELD J A. Quantitative determination of fluorinated alkyl substances by large-volume-injection liquid chromatography tandem mass spectrometry-characterization of municipal wastewaters [J]. Environmental Science & Technology, 2006, 40(1): 289-295. [3] GOSS K U, BRONNER G, HARNER T, et al. The partition behavior of fluorotelomer alcohols and olefins [J]. Environmental Science & Technology, 2006, 40(11): 3572-3577. [4] JOHANSSON J H, SALTER M E, NAVARRO J C A, et al. Global transport of perfluoroalkyl acids via sea spray aerosol [J]. Environmental Science. Processes & Impacts, 2019, 21(4): 635-649. [5] WANG Z Y, COUSINS I T, SCHERINGER M, et al. Global emission inventories for C4-C14 perfluoroalkyl carboxylic acid (PFCA) homologues from 1951 to 2030, Part I: Production and emissions from quantifiable sources [J]. Environment International, 2014, 70: 62-75. doi: 10.1016/j.envint.2014.04.013 [6] LENKA S P, KAH M, PADHYE L P. A review of the occurrence, transformation, and removal of poly-and perfluoroalkyl substances (PFAS) in wastewater treatment plants [J]. Water Research, 2021, 199: 117187. doi: 10.1016/j.watres.2021.117187 [7] 彭碧霞, 洪文俊, 李方方, 等. 浙江杭嘉湖地区水环境中全氟烷基化合物的污染特征及健康风险评估 [J]. 环境化学, 2021, 40(10): 3001-3014. doi: 10.7524/j.issn.0254-6108.2021032002 PENG B X, HONG W J, LI F F, et al. Distribution characteristics and health risk assessment of perfluoroalkyl substances in aquatic environment of Hangzhou-Jiaxing-Huzhou region in Zhejiang Province [J]. Environmental Chemistry, 2021, 40(10): 3001-3014(in Chinese). doi: 10.7524/j.issn.0254-6108.2021032002
[8] LIU L Q, QU Y X, HUANG J, et al. Per-and polyfluoroalkyl substances (PFASs) in Chinese drinking water: risk assessment and geographical distribution [J]. Environmental Sciences Europe, 2021, 33(1): 1-12. doi: 10.1186/s12302-020-00446-y [9] 鲍佳, 聂青宇, 马嘉川, 等. 水中全氟和多氟化合物的去除技术最新研究进展 [J]. 江西农业学报, 2019, 31(11): 58-65. doi: 10.19386/j.cnki.jxnyxb.2019.11.12 BAO J, NIE Q Y, MA J C, et al. Recent research progress in removal technology of perfluorinated and polyfluorinated compounds in water [J]. Acta Agriculturae Jiangxi, 2019, 31(11): 58-65(in Chinese). doi: 10.19386/j.cnki.jxnyxb.2019.11.12
[10] QIN W P, CAO L Y, LI C H, et al. Perfluoroalkyl substances stimulate insulin secretion by islet β cells via G protein-coupled receptor 40 [J]. Environmental Science & Technology, 2020, 54(6): 3428-3436. [11] LI C H, SHI Y L, LI M J, et al. Receptor-bound perfluoroalkyl carboxylic acids dictate their activity on human and mouse peroxisome proliferator-activated receptor γ [J]. Environmental Science & Technology, 2020, 54(15): 9529-9536. [12] REN X M, QIN W P, CAO L Y, et al. Binding interactions of perfluoroalkyl substances with thyroid hormone transport proteins and potential toxicological implications [J]. Toxicology, 2016, 366/367: 32-42. doi: 10.1016/j.tox.2016.08.011 [13] LI C H, REN X M, GUO L H. Adipogenic activity of oligomeric hexafluoropropylene oxide (perfluorooctanoic acid alternative) through peroxisome proliferator-activated receptor γ pathway [J]. Environmental Science & Technology, 2019, 53(6): 3287-3295. [14] XIN Y, WAN B, YU B L, et al. Chlorinated polyfluoroalkylether sulfonic acids exhibit stronger estrogenic effects than perfluorooctane sulfonate by activating nuclear estrogen receptor pathways [J]. Environmental Science & Technology, 2020, 54(6): 3455-3464. [15] RUAN Y F, LALWANI D, KWOK K Y, et al. Assessing exposure to legacy and emerging per-and polyfluoroalkyl substances via hair-the first nationwide survey in India [J]. Chemosphere, 2019, 229: 366-373. doi: 10.1016/j.chemosphere.2019.04.195 [16] JIAN J M, GUO Y, ZENG L X, et al. Global distribution of perfluorochemicals (PFCs) in potential human exposure source-A review [J]. Environment International, 2017, 108: 51-62. doi: 10.1016/j.envint.2017.07.024 [17] WARDMAN P. Reduction potentials of one‐electron couples involving free radicals in aqueous solution [J]. Journal of Physical and Chemical Reference Data, 1989, 18(4): 1637-1755. doi: 10.1063/1.555843 [18] KEY B D, HOWELL R D, CRIDDLE C S. Fluorinated organics in the biosphere [J]. Environmental Science & Technology, 1997, 31(9): 2445-2454. [19] 梁宇, 马安周, 宋茂勇, 等. 全氟辛烷磺酸生物降解研究进展 [J]. 微生物学通报, 2020, 47(8): 2536-2549. doi: 10.13344/j.microbiol.china.190981 LIANG Y, MA A Z, SONG M Y, et al. Advances in biodegradation of perfluorooctane sulfonate(PFOS) [J]. Microbiology China, 2020, 47(8): 2536-2549(in Chinese). doi: 10.13344/j.microbiol.china.190981
[20] PHONG VO H N, NGO H H, GUO W S, et al. Poly‐and perfluoroalkyl substances in water and wastewater: A comprehensive review from sources to remediation [J]. Journal of Water Process Engineering, 2020, 36: 101393. doi: 10.1016/j.jwpe.2020.101393 [21] LU D N, SHA S, LUO J Y, et al. Treatment train approaches for the remediation of per-and polyfluoroalkyl substances (PFAS): A critical review [J]. Journal of Hazardous Materials, 2020, 386: 121963. doi: 10.1016/j.jhazmat.2019.121963 [22] 许晨敏. 水中典型全氟化合物(PFCs)的吸附及光催化降解研究[D]. 南京: 南京理工大学, 2018. XU C M. Removal of typical perfluorinated compounds (PFCs) by adsorption and photocatalysis[D]. Nanjing: Nanjing University of Science and Technology, 2018(in Chinese).
[23] FURTADO R X S, SABATINI C A, ZAIAT M, et al. Perfluorooctane sulfonic acid (PFOS) degradation by optimized heterogeneous photocatalysis (TiO2/UV) using the response surface methodology (RSM) [J]. Journal of Water Process Engineering, 2021, 41: 101986. doi: 10.1016/j.jwpe.2021.101986 [24] LI X Y, ZHANG P Y, JIN L, et al. Efficient photocatalytic decomposition of perfluorooctanoic acid by indium oxide and its mechanism [J]. Environmental Science & Technology, 2012, 46(10): 5528-5534. [25] JIN C Y, LI Z L, ZHANG Y, et al. The construction of g-C3N4/Sm2+ doped Bi2WO6 2D/2D Z-scheme heterojunction for improved visible-light excited photocatalytic efficiency [J]. Separation and Purification Technology, 2019, 224: 33-43. doi: 10.1016/j.seppur.2019.05.006 [26] WANG J Z, WANG Y N, CAO C S, et al. Decomposition of highly persistent perfluorooctanoic acid by hollow Bi/BiOI1-xFx: Synergistic effects of surface plasmon resonance and modified band structures [J]. Journal of Hazardous Materials, 2021, 402: 123459. doi: 10.1016/j.jhazmat.2020.123459 [27] LI H J, ZHOU Y, TU W G, et al. State-of-the-art progress in diverse heterostructured photocatalysts toward promoting photocatalytic performance [J]. Advanced Functional Materials, 2015, 25(7): 998-1013. doi: 10.1002/adfm.201401636 [28] YANG Y Q, JI W Q, LI X Y, et al. Insights into the degradation mechanism of perfluorooctanoic acid under visible-light irradiation through fabricating flower-shaped Bi5O7I/ZnO n-n heterojunction microspheres [J]. Chemical Engineering Journal, 2021, 420: 129934. doi: 10.1016/j.cej.2021.129934 [29] YAO X Y, ZUO J Q, WANG Y J, et al. Enhanced photocatalytic degradation of perfluorooctanoic acid by mesoporous Sb2O3/TiO2 heterojunctions [J]. Frontiers in Chemistry, 2021, 9: 690520. doi: 10.3389/fchem.2021.690520 [30] LUO D D, YUAN J H, ZHOU J, et al. Synthesis of samarium doped ferrite and its enhanced photocatalytic degradation of perfluorooctanoic acid (PFOA) [J]. Optical Materials, 2021, 122: 111636. doi: 10.1016/j.optmat.2021.111636 [31] TIAN A J, WU Y B, MAO K. Enhanced performance of surface modified TiO2 nanotubes for the decomposition of perfluorooctanoic acid [J]. AIP Conference Proceedings, 2017, 1794(1): 020029. [32] ZHU C, XU J L, SONG S, et al. TiO2 quantum dots loaded sulfonated graphene aerogel for effective adsorption-photocatalysis of PFOA [J]. Science of the Total Environment, 2020, 698: 134275. doi: 10.1016/j.scitotenv.2019.134275 [33] TAN X J, CHEN G H, XING D Y, et al. Indium-modified Ga2O3 hierarchical nanosheets as efficient photocatalysts for the degradation of perfluorooctanoic acid [J]. Environmental Science:Nano, 2020, 7(8): 2229-2239. doi: 10.1039/D0EN00259C [34] GAO H P, CHEN J B, ZHANG Y L, et al. Sulfate radicals induced degradation of Triclosan in thermally activated persulfate system [J]. Chemical Engineering Journal, 2016, 306: 522-530. doi: 10.1016/j.cej.2016.07.080 [35] XU B T, AHMED M B, ZHOU J L, et al. Visible and UV photocatalysis of aqueous perfluorooctanoic acid by TiO2 and peroxymonosulfate: Process kinetics and mechanistic insights [J]. Chemosphere, 2020, 243: 125366. doi: 10.1016/j.chemosphere.2019.125366 [36] WU D, LI X K, TANG Y M, et al. Mechanism insight of PFOA degradation by ZnO assisted-photocatalytic ozonation: Efficiency and intermediates [J]. Chemosphere, 2017, 180: 247-252. doi: 10.1016/j.chemosphere.2017.03.127 [37] WU D, LI X K, ZHANG J X, et al. Efficient PFOA degradation by persulfate-assisted photocatalytic ozonation [J]. Separation and Purification Technology, 2018, 207: 255-261. doi: 10.1016/j.seppur.2018.06.059 [38] LIU X Q, CHEN Z J, TIAN K, et al. Fe3+ promoted the photocatalytic defluorination of perfluorooctanoic acid (PFOA) over In2O3 [J]. ACS ES& T Water, 2021, 1(11): 2431-2439. [39] ZHU Y M, XU T Y, ZHAO D Y, et al. Adsorption and solid-phase photocatalytic degradation of perfluorooctane sulfonate in water using gallium-doped carbon-modified titanate nanotubes [J]. Chemical Engineering Journal, 2021, 421: 129676. doi: 10.1016/j.cej.2021.129676 [40] 朱佳新, 熊裕华, 郭锐. 二氧化钛光催化剂改性研究进展 [J]. 无机盐工业, 2020, 52(3): 23-27,54. doi: 10.11962/1006-4990.2019-0245 ZHU J X, XIONG Y H, GUO R. Research progress in modification of TiO2 photocatalyst [J]. Inorganic Chemicals Industry, 2020, 52(3): 23-27,54(in Chinese). doi: 10.11962/1006-4990.2019-0245
[41] XU T Y, ZHU Y M, DUAN J, et al. Enhanced photocatalytic degradation of perfluorooctanoic acid using carbon-modified bismuth phosphate composite: Effectiveness, material synergy and roles of carbon [J]. Chemical Engineering Journal, 2020, 395: 124991. doi: 10.1016/j.cej.2020.124991 [42] LIU X Q, XU B T, DUAN X G, et al. Facile preparation of hydrophilic In2O3 nanospheres and rods with improved performances for photocatalytic degradation of PFOA [J]. Environmental Science:Nano, 2021, 8(4): 1010-1018. doi: 10.1039/D0EN01216E [43] LI T F, WANG C S, WANG T C, et al. Highly efficient photocatalytic degradation toward perfluorooctanoic acid by bromine doped BiOI with high exposure of (001) facet [J]. Applied Catalysis B:Environmental, 2020, 268: 118442. doi: 10.1016/j.apcatb.2019.118442 [44] LI F, WEI Z S, HE K, et al. A concentrate-and-destroy technique for degradation of perfluorooctanoic acid in water using a new adsorptive photocatalyst [J]. Water Research, 2020, 185: 116219. doi: 10.1016/j.watres.2020.116219 [45] PARK H, VECITIS C D, CHENG J, et al. Reductive defluorination of aqueous perfluorinated alkyl surfactants: Effects of ionic headgroup and chain length[J]. The Journal of Physical Chemistry A. 2009, 113(4): 690-696. [46] LIU Z K, BENTEL M J, YU Y C, et al. Near-quantitative defluorination of perfluorinated and fluorotelomer carboxylates and sulfonates with integrated oxidation and reduction [J]. Environmental Science & Technology, 2021, 55(10): 7052-7062. [47] MURCIA J J, ÁVILA-MARTÍNEZ E G, ROJAS H, et al. Powder and nanotubes titania modified by dye sensitization as photocatalysts for the organic pollutants elimination [J]. Nanomaterials (Basel, Switzerland), 2019, 9(4): 517. doi: 10.3390/nano9040517 [48] LIU J X, ZOU Y J, CRUZ D, et al. Ligand-metal charge transfer induced via adjustment of textural properties controls the performance of single-atom catalysts during photocatalytic degradation [J]. ACS Applied Materials & Interfaces, 2021, 13(22): 25858-25867. [49] O`BOCKRIS M J. A primer on electrocatalysis [J]. Journal of the Serbian Chemical Society, 2005, 70(3): 475-487. doi: 10.2298/JSC0503475B [50] 周键, 王三反. 钛基二氧化铅阳极去除有机污染物的研究进展 [J]. 环境工程, 2014, 32(12): 1-4. doi: 10.13205/j.hjgc.201412001 ZHOU J, WANG S F. The research progress on the removal of organic pollutants by ti-based lead dioxide anode [J]. Environmental Engineering, 2014, 32(12): 1-4(in Chinese). doi: 10.13205/j.hjgc.201412001
[51] YANG B, WANG J B, JIANG C J, et al. Electrochemical mineralization of perfluorooctane sulfonate by novel F and Sb co-doped Ti/SnO2 electrode containing Sn-Sb interlayer [J]. Chemical Engineering Journal, 2017, 316: 296-304. doi: 10.1016/j.cej.2017.01.105 [52] ZHAO G H, ZHANG Y G, LEI Y Z, et al. Fabrication and electrochemical treatment application of a novel lead dioxide anode with superhydrophobic surfaces, high oxygen evolution potential, and oxidation capability [J]. Environmental Science & Technology, 2010, 44(5): 1754-1759. [53] LOU Z M, WANG J Z, WANG S B, et al. Strong hydrophobic affinity and enhanced •OH generation boost energy-efficient electrochemical destruction of perfluorooctanoic acid on robust ceramic/PbO2-PTFE anode [J]. Separation and Purification Technology, 2022, 280: 119919. doi: 10.1016/j.seppur.2021.119919 [54] WANG Q N, LIU M Y, ZHAO H Y, et al. Efficiently degradation of perfluorooctanoic acid in synergic electrochemical process combining cathodic electro-Fenton and anodic oxidation [J]. Chemical Engineering Journal, 2019, 378: 122071. doi: 10.1016/j.cej.2019.122071 [55] LIU G S, ZHOU H, TENG J, et al. Electrochemical degradation of perfluorooctanoic acid by macro-porous titanium suboxide anode in the presence of sulfate [J]. Chemical Engineering Journal, 2019, 371: 7-14. doi: 10.1016/j.cej.2019.03.249 [56] LIU Y M, FAN X F, QUAN X, et al. Enhanced perfluorooctanoic acid degradation by electrochemical activation of sulfate solution on B/N codoped diamond [J]. Environmental Science & Technology, 2019, 53(9): 5195-5201. [57] 黄海彬, 陈栩竺, 施乐华, 等. 二氧化铅阳极改性及电化学氧化性能研究进展 [J]. 广东石油化工学院学报, 2019, 29(3): 71-75. doi: 10.3969/j.issn.2095-2562.2019.03.016 HUANG H B, CHEN X Z, SHI L H, et al. Research process of the lead dioxide anode's modification and electrochemical oxidation performance [J]. Journal of Guangdong University of Petrochemical Technology, 2019, 29(3): 71-75(in Chinese). doi: 10.3969/j.issn.2095-2562.2019.03.016
[58] LIN H, NIU J F, LIANG S T, et al. Development of macroporous Magnéli phase Ti4O7 ceramic materials: As an efficient anode for mineralization of poly-and perfluoroalkyl substances [J]. Chemical Engineering Journal, 2018, 354: 1058-1067. doi: 10.1016/j.cej.2018.07.210 [59] SHI H H, WANG Y Y, LI C G, et al. Degradation of perfluorooctanesulfonate by reactive electrochemical membrane composed of magnéli phase titanium suboxide [J]. Environmental Science & Technology, 2019, 53(24): 14528-14537. [60] HUANG D H, WANG K X, NIU J F, et al. Amorphous Pd-loaded Ti4O7 electrode for direct anodic destruction of perfluorooctanoic acid [J]. Environmental Science & Technology, 2020, 54(17): 10954-10963. [61] ZHUO Q F, LUO M Q, GUO Q W, et al. Electrochemical oxidation of environmentally persistent perfluorooctane sulfonate by a novel lead dioxide anode [J]. Electrochimica Acta, 2016, 213: 358-367. doi: 10.1016/j.electacta.2016.07.005 [62] DUAN X Y, WANG W Y, WANG Q, et al. Electrocatalytic degradation of perfluoroocatane sulfonate (PFOS) on a 3D graphene-lead dioxide (3DG-PbO2) composite anode: Electrode characterization, degradation mechanism and toxicity [J]. Chemosphere, 2020, 260: 127587. doi: 10.1016/j.chemosphere.2020.127587 [63] WANG C, ZHANG T A, YIN L F, et al. Enhanced perfluorooctane acid mineralization by electrochemical oxidation using Ti3+ self-doping TiO2 nanotube arrays anode [J]. Chemosphere, 2022, 286: 131804. doi: 10.1016/j.chemosphere.2021.131804 [64] XU L, QIAN X B, WANG K X, et al. Electrochemical mineralization mechanisms of perfluorooctanoic acid in water assisted by low frequency ultrasound [J]. Journal of Cleaner Production, 2020, 263: 121546. doi: 10.1016/j.jclepro.2020.121546 [65] WANG K X, HUANG D H, WANG W L, et al. Enhanced perfluorooctanoic acid degradation by electrochemical activation of peroxymonosulfate in aqueous solution [J]. Environment International, 2020, 137: 105562. doi: 10.1016/j.envint.2020.105562 [66] ZHUO Q F, DENG S B, YANG B, et al. Efficient electrochemical oxidation of perfluorooctanoate using a Ti/SnO2-Sb-Bi anode [J]. Environmental Science & Technology, 2011, 45(7): 2973-2979. [67] BEHARA D K, TAMMINENI J, MAHESWARI M S. TiO2/ZnO: Type-II Heterostructures for electrochemical crystal violet dye degradation studies [J]. Macedonian Journal of Chemistry and Chemical Engineering, 2020, 39(2): 217-226. doi: 10.20450/mjcce.2020.2058 [68] TANG B, SHI H J, FAN Z Y, et al. Preferential electrocatalytic degradation of 2, 4-dichlorophenoxyacetic acid on molecular imprinted mesoporous SnO2 surface [J]. Chemical Engineering Journal, 2018, 334: 882-890. doi: 10.1016/j.cej.2017.10.086 [69] ZHANG C, JIANG Y H, LI Y L, et al. Three-dimensional electrochemical process for wastewater treatment: A general review [J]. Chemical Engineering Journal, 2013, 228: 455-467. doi: 10.1016/j.cej.2013.05.033 [70] LI J, YAN J F, YAO G, et al. Improving the degradation of atrazine in the three-dimensional (3D) electrochemical process using CuFe2O4 as both particle electrode and catalyst for persulfate activation [J]. Chemical Engineering Journal, 2019, 361: 1317-1332. doi: 10.1016/j.cej.2018.12.144 [71] PENG Y P, CHEN H L, HUANG C P. The synergistic effect of photoelectrochemical (PEC) reactions exemplified by concurrent perfluorooctanoic acid (PFOA) degradation and hydrogen generation over carbon and nitrogen codoped TiO2 nanotube arrays (C-N-TNTAs) photoelectrode [J]. Applied Catalysis B:Environmental, 2017, 209: 437-446. doi: 10.1016/j.apcatb.2017.02.084 [72] GU Y R, LIU T Z, WANG H J, et al. Hydrated electron based decomposition of perfluorooctane sulfonate (PFOS) in the VUV/sulfite system [J]. Science of the Total Environment, 2017, 607/608: 541-548. doi: 10.1016/j.scitotenv.2017.06.197 [73] SU Y M, RAO U, KHOR C M, et al. Potential-driven electron transfer lowers the dissociation energy of the C-F bond and facilitates reductive defluorination of perfluorooctane sulfonate (PFOS) [J]. ACS Applied Materials & Interfaces, 2019, 11(37): 33913-33922.