title: Exchangeable cations-mediated photodegradation of polycyclic aromatic hydrocarbons (PAHs) on smectite surface under visible light.
abstract: Clay minerals saturated with different exchangeable cations are expected to play various roles in photodegradation of polycyclic aromatic hydrocarbons (PAHs) via direct and/or indirect pathways on clay surfaces. In the present study, anthracene and phenanthrene were selected as molecule probes to investigate the roles of exchangeable cations on their photodegradation under visible light irradiation. For five types of cation-modified smectite clays, the photodegradation rate of anthracene and phenanthrene follows the order: Fe(3+)>Al(3+)>Cu(2+)>>Ca(2+)>K(+)>Na(+), which is consistent with the binding energy of cation-π interactions between PAHs and exchangeable cations. The result suggests that PAHs photolysis rate depends on cation-π interactions on clay surfaces. Meanwhile, the deposition of anthracene at the Na(+)-smectite and K(+)-smectite surface favors solar light absorption, resulting in enhanced direct photodecomposition of PAHs. On the other hand, smectite clays saturated with Fe(3+), Al(3+), and Cu(2+) are highly photoreactive and can act as potential catalysts giving rise to oxidative radicals such as O2(-) , which initiate the transformation of PAHs. The present work provides valuable insights into understanding the transformation and fate of PAHs in the natural soil environment and sheds light on the development of technologies for contaminated land remediation.
authors.affiliation: Laboratory of Environmental Sciences and Technology, Xinjiang Technical Institute of Physics & Chemistry; Key Laboratory of Functional Materials and Devices for Special Environments, Chinese Academy of Sciences, Urumqi 830011, China. Electronic address: jiahz@ms.xjb.ac.cn.
authors.forename: Hanzhong
authors.initials: H
authors.lastname: Jia
authors.affiliation: Laboratory of Environmental Sciences and Technology, Xinjiang Technical Institute of Physics & Chemistry; Key Laboratory of Functional Materials and Devices for Special Environments, Chinese Academy of Sciences, Urumqi 830011, China.
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.affiliation: Laboratory of Environmental Sciences and Technology, Xinjiang Technical Institute of Physics & Chemistry; Key Laboratory of Functional Materials and Devices for Special Environments, Chinese Academy of Sciences, Urumqi 830011, China; School of Geology and Mining Engineering, Xinjiang University, Urumqi 830046, China.
authors.forename: Hongxia
authors.initials: H
authors.lastname: Chen
authors.affiliation: Laboratory of Environmental Sciences and Technology, Xinjiang Technical Institute of Physics & Chemistry; Key Laboratory of Functional Materials and Devices for Special Environments, Chinese Academy of Sciences, Urumqi 830011, China; School of Geology and Mining Engineering, Xinjiang University, Urumqi 830046, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Laboratory of Environmental Sciences and Technology, Xinjiang Technical Institute of Physics & Chemistry; Key Laboratory of Functional Materials and Devices for Special Environments, Chinese Academy of Sciences, Urumqi 830011, China.
authors.forename: Xiyou
authors.initials: X
authors.lastname: Li
authors.affiliation: Laboratory of Environmental Sciences and Technology, Xinjiang Technical Institute of Physics & Chemistry; Key Laboratory of Functional Materials and Devices for Special Environments, Chinese Academy of Sciences, Urumqi 830011, China. Electronic address: cywang@ms.xjb.ac.cn.
authors.forename: Chuanyi
authors.initials: C
authors.lastname: Wang
mesh_terms: D000873:Anthracenes / Q000737:chemistry* / Q000528:radiation effects; D002412:Cations / Q000737:chemistry; D010616:Phenanthrenes / Q000737:chemistry* / Q000528:radiation effects; D010782:Photolysis; D017640:Silicates
chemical_list: D000873:Anthracenes; D002412:Cations; D010616:Phenanthrenes; D017640:Silicates; C033214:Smectite
keywords: Cation–π interaction; Clay minerals; Exchangeable cation; Photolysis; Polycyclic aromatic hydrocarbons (PAHs)