The　heterogeneous　photo−Fenton　method　is　a　promising　technology　for　wastewater　treatment　based　on　the　development　of　efficient　catalysts　through　which　the　inefficient　Fe(III)/Fe(II)　cycles　and　low　utilization　of　H2O2　are　optimized.　In　this　work,　viable　heterogeneous　photo−Fenton　catalysts　(NCS)　are　synthesized　by　in　situ　compounding　nitrogen−doped　carbon　quantum　dots　(N−CQDs)　with　schwertmannite　(SCH).　Specifically,　the　NCS　catalysts　exhibit　greatly　enhanced　capacity　for　chlortetracycline　(CTC)　degradation,　in　comparison　with　those　of　the　pristine　SCH　and　N−CQDs,　with　a　remarkable　efficiency　of　95.12%　at　a　wide　pH　range　(3.0–7.0).　In　particular,　this　allows　an　efficient　Fe(III)/Fe(II)　conversion　due　to　the　fast　electron　transport　capability　provided　by　N−CQDs,　coupled　to　an　excellent　structural　stability　of　the　catalysts.　Main　active　species　including　•OH,　•O2−　and　1O2　are　identified　in　the　degradation　process,　and　a　possible　degradation　mechanism　is　tentatively　proposed.　In　addition,　related　cytotoxicity　of　CTC　degradation　intermediates　is　verified　via　co−culturing　with　E.　coli.　This　study　provides　a　new　strategy　to　overcome　the　disadvantages　of　photo−Fenton　processes　and　develop　new　technologies　for　advanced　water　treatment.　©　2023　Elsevier　Ltd