Photoelectrochemical Reforming of PET Plastics using a Ternary CoOCl/SrTiO ₃ /TiO ₂ Heterojunction Membrane Electrode

ABSTRACT Photoelectrochemical (PEC) upcycling of plastic waste into value‐added chemicals and hydrogen fuel offers a sustainable approach to mitigate pollution while producing clean energy. Here, we report a flow‐through ternary heterojunction membrane photoanode (CoOCl/SrTiO ₃ /TiO ₂ ) that integrates membrane‐confined mass transport with self‐adaptive cocatalyst reconstruction to enable selective PET photoreforming. The optimized CoOCl/SrTiO ₃ /TiO ₂ membrane achieves a GA production rate of 10.76 µmol cm ⁻² h ⁻¹ with 80% selectivity, alongside a hydrogen evolution rate of 4.49 µmol cm ⁻² h ⁻¹ , significantly outperforming TiO ₂ and SrTiO ₃ /TiO ₂ binary photoanodes. Post‐reaction analysis reveals that CoOCl undergoes ion displacement reactions in the alkaline electrolyte and reconstructs into β‐CoOOH, which serves as an efficient hole transfer cocatalyst and drives selective oxidation of ethylene glycol from PET via a ¹ O ₂ pathway. This dynamic reconstruction ensures high durability over repeated cycles (7% decay after five cycles). Such monolithic flow‐through membrane architecture and reconstruction of CoOCl into β‐CoOOH synergistically enhance mass transport, charge utilization, and oxidation selectivity. This work thus establishes a membrane photoelectrode technology for sustainable plastic valorization and solar fuel production.