Peroxymonosulfate activation by assistance of Co₃O₄/g-C₃N₄ nanocomposite and UVC for efficient microplastic photodegradation

Microplastics (MPs) are a group of increasing pollutants in human society, and their emissions pose serious threats to marine life and human health. Therefore, developing an advanced oxidation process (AOP) with the assistance of photocatalysts can be a suitable solution for removing these pollutants under light. The present study described an efficient strategy for preparing Co₃O₄/g-C₃N₄ nanostructures as a peroxymonosulfate (PMS) activator for degrading MPs under UVC light. First, g-C₃N₄with hexagonal morphology was fabricated using the solvothermal method. Subsequently, the Co₃O₄metal oxide derived from ZIF-67 was grown on the surface of g-C₃N₄to create a Co₃O₄/g-C₃N₄nanocomposite. The loading of Co₃O₄on the g-C₃N₄surface was further confirmed with XRD pattern and FESEM images after calcination, which provided a suitable nanocomposite for PMS activation under UVC light. The weight loss of polyethylene (PET) and polypropylene (PP) in the presence of 1.0 g L⁻¹ nanocomposite 0.6 g L⁻¹ PMS reached about 48 to 55 % under UVC light, respectively. The radicals, including SO₄•⁻, •OH, and •O₂⁻, contributed to MPs degradation The suitable photodegradation activity originated from the synergistic effect between nanocomposite and activated microplastics in the presence of UV light. This study could provide a useful criterion for the fabrication of nanocomposites and provide a new route for the practical remediation of this type of pollutant. • Co 3 O 4 /g-C 3 N 4 nanocomposite was developed for UVC-driven microplastic degradation. • The nanocomposite achieved 54 % PET and 48 % PP degradation under UVC/PMS. • Active radicals from Z-scheme heterojunction drive the degradation mechanism.. • Dosage, pH, and concentration parameters were optimised. • The study provides a scalable solution for microplastic remediation.