Cerium-infused bismuth ferrite: a piezoelectric powerhouse igniting Fenton-like catalysis to degrade microplastics

Abstract

Microplastic (MP) pollution is a global environmental concern, and conventional advanced oxidation processes (AOPs) for MP removal often require harsh conditions. Meanwhile, the environmental risks of degradation byproducts are overlooked. Herein, Ce-doped BiFeO₃ (BCFO) was synthesized as a piezoelectric catalyst to activate a Fenton-like process for the degradation of polyethylene terephthalate (PET)-MPs under mild conditions with ultrasound-assisted treatment and H₂O₂. Results exhibited an outstanding performance, achieving a 39.2% weight loss of PET-MPs within 40 h. The Ce doping promoted the Fe cycle in the Fenton-like process and created new H₂O₂ reaction sites on BCFO with lower adsorption energy (−3.9502 eV) and activation energy (−0.8395 eV) compared with BiFeO₃ (E_ads = −0.3087 eV and E_act = 3.5779 eV). Besides, the effects of various parameters affecting the formation of reactive oxygen species (ROSs) and the degradation pathway of MPs were analyzed systematically. Toxicity assessments confirmed that the intermediates of degraded PET-MPs were non-toxic to biological organisms, and plants grew normally in the degraded solution. This study provides a new approach for designing environmentally friendly methods for MP removal under ambient conditions.