Tetracycline　(TC)　antibiotics,　extensively　utilized　in　livestock　farming　and　aquaculture,　pose　significant　environmental　challenges.　Photocatalysis,　leveraging　renewable　sunlight　and　reusable　photocatalysts,　offers　a　promising　avenue　for　mitigating　TC　pollution.　However,　identifying　robust　photocatalysts　remains　a　formidable　challenge.　This　study　introduces　a　novel　hollow-flower-ball-like　nanoheterojunction　composed　of　a　nitrogen-rich　covalent　organic　framework　(N-COF)　coupled　with　BiOBr　(BOB),　a　semiconductor　with　a　higher　Fermi　level.　The　synthesized　N-COF/BOB　S-scheme　nanoheterojunction　features　an　expanded　contact　interface,　strengthened　chemical　bonding,　and　unique　band　topologies.　The　N-COF/BOB　composites　showcased　exceptional　TC　degradation　performance,　achieving　an　81.2%　removal　of　60　mg/L　TC　within　2　h,　markedly　surpassing　the　individual　efficiencies　of　N-COF　and　BOB　by　factors　of　3.80　and　5.96,　respectively.　Furthermore,　the　total　organic　carbon　(TOC)　removal　efficiency　highlights　a　superior　mineralization　capacity　in　the　N-COF/BOB　composite　compared　to　the　individual　components,　N-COF　and　BOB.　The　toxicity　assessment　revealed　that　the　degradation　intermediates　possess　diminished　environmental　toxicity.　This　enhanced　performance　is　ascribed　to　the　robust　S-scheme　nanoheterojunction　structure,　which　promotes　efficient　photoinduced　electron　transfer　from　BOB　to　N-COF.　This　process　also　augments　the　separation　of　photogenerated　charge　carriers,　resulting　in　an　increased　yield　of　superoxide　radicals　(∙O2−)　and　hydroxyl　radicals　(∙OH).　These　reactive　species　significantly　contribute　to　the　degradation　and　mineralization　of　TC.　Consequently,　this　study　introduces　a　sustainable　approach　for　addressing　emerging　antibiotic　contaminants,　employing　COF-based　photocatalysts.　©　2024　Elsevier　Inc.