Efficient photodegradation of PFOA using spherical BiOBr modified TiO 2 via hole-remained oxidation mechanism

Photo-induced holes (h ) oxidation is an efficient approach for perfluorooctanoic acid (PFOA; C F COOH) removal. To maintain a high amount of h on the surface of photocatalysts participating in the PFOA photodegradation could be a critical issue. Herein, a highly efficient spherical BiOBr-modified n...

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Bibliographic Details
Published inChemosphere (Oxford) Vol. 298; p. 134176
Main Authors Chen, Fengjie, He, Anen, Wang, Yarui, Yu, Wanchao, Chen, Haoze, Geng, Fanglan, Li, Zhunjie, Zhou, Zhen, Liang, Yong, Fu, Jianjie, Zhao, Lixia, Wang, Yawei
Format Journal Article
LanguageEnglish
Published England 01.07.2022
Subjects
Direct oxidation with holes
Holes remained
PFOA photodegradation
BiOBr-Modified TiO
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Summary:Photo-induced holes (h ) oxidation is an efficient approach for perfluorooctanoic acid (PFOA; C F COOH) removal. To maintain a high amount of h on the surface of photocatalysts participating in the PFOA photodegradation could be a critical issue. Herein, a highly efficient spherical BiOBr-modified nano-TiO (P25) was synthesised and used for PFOA photodegradation through direct oxidation with h . A high number of h could be generated and remain on the surface of P25/BiOBr due to the appropriate position of the conduction band (CB) and valence band (VB) levels between P25 and BiOBr. Meanwhile, PFOA molecules were coordinated to the P25/BiOBr's surface via unidentate binding, being directly activated and oxidised by h , resulting in a decomposition yield of 99.5% (100 mg/L) under simulated solar light irradiation within 100 min, at the initial pH condition (3.5). A stepwise photodegradation pathway was proposed due to the significant intermediates detected as the short-chain perfluorinated carboxylic acids (C2-C7). Reactive oxygen species (ROS) generation, scavenging and trapping analysis indicated that the direct oxidation on h followed PFOA degradation. In a real aqueous environment of Tangxun lake (adjusted pH 3.5), stable common anions and natural organic matter (NOM) would restrain the PFOA photodegradation. However, adding 10 mg/L of NO or HA could reduce the inhibition effect of PFOA photodegradation. These findings gave an alternative strategy to drive an h directly oxidation to treat PFOA contaminated water bodies.
ISSN:1879-1298