Electrocatalytic Depolymerization of PET Plastic Fibers for Circular Textiles

Poly (ethylene terephthalate) (PET) fibers constitute the largest share of global PET and are central to textiles and technical fabrics, yet high crystallinity, strong orientation, and complex finishing make them resistant to degradation and major sources of persistent microplastics. Conventional routes such as mechanical reprocessing, thermal depolymerization, hydrolysis, and alcoholysis were adapted from bulk PET but are inefficient for fibers due to limited accessibility, surface barriers, and poor selectivity toward high-purity monomers. This review adopts a fiber-centered perspective on electrocatalytic PET degradation that integrates structural, interfacial, and process considerations. It compares multiscale structural and chemical differences between fibers and bulk PET, and analyzes how pretreatments such as desizing, swelling, and surface activation condition fibers for electrochemical reactivity. It outlines fundamental principles of electrocatalytic depolymerization and classifies catalysts by structural descriptors including crystallinity, composition, and interfaces, supported by a consolidated dataset. Distinct from previous surveys, the review foregrounds fiber-specific interfaces and pretreatments and proposes a structure-centric framework for catalyst design. Highlights include transferable descriptors for cross-comparison and explicit coupling of pretreatment with catalyst selection. Looking ahead, priority is placed on scalable, continuous electrocatalytic platforms that link renewable electricity with circular textile recycling.