Fouling　control　is　the　most　critical　concern　in　the　implementation　of　nanofiltration　(NF)　for　dye　wastewater　treatment.　In　this　study,　integration　of　NF　and　Fenton-like　advanced　oxidation　was　realized　by　tailoring　a　thin　film　composite　NF　membrane　(TFNi)　with　in　situ　synthesized　PDA/MnO2　interlayer.　TFNi　was　optimized　by　controlling　the　amount　of　MnO2　nanoparticles　incorporated　within　the　interlayer　which　endowed　the　membrane　with　self-cleaning　property.　Besides　it　improved　the　membrane　surface　hydrophilicity　and　optimized　the　water　transport　path,　resulting　in　alleviated　fouling　risks　and　an　enhanced　water　permeance　of　24　±　2　L　m−2　h−1　bar−1　compared　to　the　control　membrane.　Fouling　and　subsequent　chemical　cleaning　experiments　were　carried　out　on　TFNi　under　various　water　chemistry　conditions　to　elucidate　the　underlying　mechanisms　governing　the　self-cleaning　properties.　Accordingly,　a　high　flux　recovery　ratio　(FRR)　(above　95%)　was　maintained　thanks　to　the　generation　of　free　radicals　by　MnO2–H2O2　system　which　was　validated　by　determining　the　free　radical　scavenging　activities.　Moreover,　the　interlayer　confined　radicals　can　facilitate　the　decomposition　of　foulants　on　TFNi.　Conclusively,　H2O2-initiated　self-cleaning　of　TFNi　can　be　of　great　prospect　for　the　efficient　treatment　of　dye　wastewater　via　in-situ　generated　free　radicals.　©　2023　Elsevier　B.V.