Photocatalytic degradation of different types of microplastics by TiOx/ZnO tetrapod photocatalysts

Yanling He; Atta Ur Rehman; Muxian Xu; Christelle A Not; Alan M C Ng; Aleksandra B Djurišić

doi:10.1016/j.heliyon.2023.e22562

Photocatalytic degradation of different types of microplastics by TiO_x/ZnO tetrapod photocatalysts

Heliyon. 2023 Nov 18;9(11):e22562. doi: 10.1016/j.heliyon.2023.e22562. eCollection 2023 Nov.

Authors

Yanling He¹, Atta Ur Rehman¹, Muxian Xu^{2

3}, Christelle A Not⁴, Alan M C Ng², Aleksandra B Djurišić¹

Affiliations

¹ Department of Physics, The University of Hong Kong, Pokfulam, Hong Kong, China.
² Department of Physics & Core Research Facilities, Southern University of Science and Technology, Shenzhen, 518055, China.
³ Department of Physics, Boston College, Chestnut Hill, MA, USA.
⁴ Dept. of Earth Science, The University of Hong Kong, Pokfulam, Hong Kong, China.

Abstract

We investigated the use of titania coated ZnO tetrapods for photocatalytic degradation of two common types of microplastics, namely polyethylene (PE) microparticles and polyester (PES) microfibers. We found that the plastics morphology affects the rate of degradation, and that the use of electron scavengers is needed to maintain the reactivity of the photocatalysts over a prolonged period of time. Complete mass loss of PE and PES is achieved under UV illumination for 480 h and 624 h, respectively. In addition to pristine microplastics, the degradation of environmental microplastics sample (consisting primarily of polypropylene) was also demonstrated, though in this case longer degradation time (∼816 h) was needed to achieve complete mass loss of the samples.

Keywords: Microplastics; Photocatalysis; TiO2; ZnO.