The Role of the Reactive Species Involved in the Photocatalytic Degradation of HDPE Microplastics Using C,N-TiO2 Powders

Polymers

MariaCamila Ariza-Tarazona¹  Cristina Siligardi¹  JuanFrancisco Villarreal-Chiu²  ErikaIveth Cedillo-González²  JuanManuel Hernández-López²  AranzaDenisse Vital-Grappin²  ValeriaMontserrat Luna-Hernández² 

[1] Department of Engineering “Enzo Ferrari”, University of Modena and Reggio Emilia, Via P. Vivarelli 10/1, 41125 Modena, Italy;Facultad de Ciencias Químicas, Universidad Autónoma de Nuevo León, Av. Universidad S/N Ciudad Universitaria, San Nicolás de los Garza C.P. 66455, Nuevo León, Mexico;

关键词: microplastics;    HDPE;    microbeads;    photocatalysis;    scavengers;    C,N-TiO₂;   

DOI  :  10.3390/polym13070999

来源: DOAJ

【 摘 要 】

Microplastics (MPs) are distributed in a wide range of aquatic and terrestrial ecosystems throughout the planet. They are known to adsorb hazardous substances and can transfer them across the trophic web. To eliminate MPs pollution in an environmentally friendly process, we propose using a photocatalytic process that can easily be implemented in wastewater treatment plants (WWTPs). As photocatalysis involves the formation of reactive species such as holes (h⁺), electrons (e⁻), hydroxyl (OH^●), and superoxide ion (O₂^●−) radicals, it is imperative to determine the role of those species in the degradation process to design an effective photocatalytic system. However, for MPs, this information is limited in the literature. Therefore, we present such reactive species’ role in the degradation of high-density polyethylene (HDPE) MPs using C,N-TiO₂. Tert-butanol, isopropyl alcohol (IPA), Tiron, and Cu(NO₃)₂ were confirmed as adequate OH^●, h⁺, O₂^●− and e⁻ scavengers. These results revealed for the first time that the formation of free OH^● through the pathways involving the photogenerated e⁻ plays an essential role in the MPs’ degradation. Furthermore, the degradation behaviors observed when h⁺ and O₂^●− were removed from the reaction system suggest that these species can also perform the initiating step of degradation.

【 授权许可】

Unknown