Humic　acid　(HA),　a　widely　prevalent　natural　organic　matter　in　aquatic　environments,　poses　serious　health　risks　due　to　its　potential　to　form　carcinogenic　by-products　during　water　treatment.　While　the　photo-Fenton　process　can　be　employed　for　HA　degradation,　its　effectiveness　is　often　hindered　by　the　poor　catalytic　performance　of　conventional　catalysts.　In　this　study,　Co3O4　was　modified　with　nitrogen-doped　carbon　quantum　dots　(NCDs)　and　immobilized　on　a　PVDF　membrane.　Compared　with　Co3O4/PVDF,　Co3O4/NCDs/PVDF　system　achieved　85.1　%　HA　removal　and　66　%　mineralization　within　60　min　through　photocatalytic　peroxymonosulfate　(PMS)　activation　as　well　as　showed　excellent　stability　in　cycle　experiments.　The　incorporation　of　NCDs　enhanced　the　synergistic　effect　between　light　and　PMS,　improved　light　absorption　due　to　the　narrowed　bandgap　of　Co3O4/NCDs/PVDF,　and　played　a　significant　role　in　generating　the　primary　reactive　species,　1O2.　Additionally,　Co3O4/NCDs/PVDF　effectively　controlled　Co　ions　leaching.　Finally,　the　degradation　intermediates　were　identified,　and　the　degradation　pathways　were　proposed.　The　photo-Fenton　degradation　of　HA　preferentially　broke　unsaturated　bonds　and　degraded　aromatic　ring　compounds.　The　Co3O4/NCDs/PVDF　photo-Fenton　catalytic　system　serves　as　an　effective　approach　for　boosting　the　efficiency　of　photo-Fenton　degradation.　©　2025　The　Institution　of　Chemical　Engineers