Polyethylene terephthalate pre-protected and iron, oxygen co-doped carbon nitride for enhanced photocatalytic degradation of organic pollutants.

Water pollution has become an urgent issue for the healthy and sustainable development of human society. In this study, a highly active catalyst (10Fe@PET/CN) was synthesized using polyethylene terephthalate (PET) pre-protection combined with iron (Fe), oxygen (O) co-doping strategies. The introduction of PET effectively inhibited the oxidation and agglomeration of Fe atoms. Co-doping O atoms with Fe altered the morphology and structure of carbon nitride (CN), optimizing the energy band structure of 10Fe@PET/CN and introducing nitrogen vacancies (V). These modifications broadened the visible light response range of the 10Fe@PET/CN and enhanced the separation efficiency of photogenerated carriers. The transfer of electrons from the vicinity of nitrogen (N) and O atoms to the Fe atoms facilitated efficient electron migration, which in turn activated surface reactive oxygen species (·O). The 10Fe@PET/CN photocatalyst demonstrated remarkable efficiency in degrading organic pollutants within 40 min. Specifically, the degradation rate of 2-Mercaptobenzothiazole (MBT) was 8.31 times higher compared to pristine CN, with a 59.35% increase in removal efficiency. Finally, the performance of 10Fe@PET/CN was minimally affected by complex real water bodies and real-world waste plastics doping, indicating its robustness and practical applicability. This study not only advances the development of CN-based materials for efficient water pollution remediation but also addresses the pressing issue of plastic pollution. By transforming waste PET into a highly active photocatalyst, this approach offers sustainable and dual-purpose solutions to environmental challenges.