High-definition mass spectrometry tracking: Enhanced photocatalytic chain scission and mineralization of polyamide 6 microplastics under solar irradiation

The photodegradable polyamide 6 (PA6) material is prepared by adding 2.5% composite photocatalyst into PA6 fibers by centrifugal electrospinning. Even in the absence of microorganisms, the material can be completely mineralized into CO2 and H2O by photocatalysis under solar irradiation. The material is expected to be a replacement for traditional disposable PA6 materials to reduce the PA6 microplastics. In order to study the degradation process of PA6, the photodegradation behavior of the model compounds was investigated, and the photocatalytic chain scission and mineralization processes of PA6 were tracked and analyzed via HDMS. It is found that the breaking of PA6 long chain is mainly caused by the oxidation of the C atoms adjacent NH2 and the fracture of CONH. In addition, the active species that promote the degradation process are main ·OH and minor ·O2−. This analytical idea is beneficial to study the photodegradation pathway of polymers containing amide bonds.