Efficient Photocatalytic Degradation of the Persistent PET Fiber-Based Microplastics over Pt Nanoparticles Decorated N-Doped TiO2 Nanoflowers

Fiber-based microplastics (FMPs) are highly persistent and ubiquitously exist in the wastewater of textile industry and urban sewage. It remains challenging to completely remove such newly emerged organic pollutants by the predominant physical techniques. In this work, we investigated a photocatalytic degradation catalyzed by TiO2 catalyst to demonstrate the feasibility of implementing efficient chemical protocol to fast degrading polyethylene terephthalate (PET)-FMPs (a major FMP type existing in environment). The result shows that a hydrothermal pretreatment (180 °C/12 h) is necessary to induce the initial rough appearance and molecular weight reduction. With the comprehensive action of the nano-flower shaped N doped-TiO2 catalyst (Pt@N-TiO2-1.5%) on the relatively low molecular weight intermediates, an approximate 29% weight loss was induced on the pretreated PET-FMPs, which is about 8 times superior to the untreated sample. This work not only achieves a superior degradation effect of PET-FMPs, but also provides a new inspiration for the proposal of reduction strategies in the field of environmental remediation in the future.Graphical abstract