Transition　metals　are　frequently　used　to　create　catalysts　that　activate　peroxymonosulfate　(PMS)　to　degrade　water　contaminants.　However,　the　degradation　efficiency　may　be　decreased　if　metal　ions　are　released　into　the　solution.　In　this　work,　a　one-step　calcination　method　was　used　to　modify　graphitic　carbon　nitride　(CN)　in　the　presence　of　Co　and　S.　The　synthesis　of　CoS₂　was　notably　aided　by　the　doping　of　S,　which　also　improved　the　degradation　efficiency　of　CBZ　by　penetrating　the　tri-s-triazine　ring　of　CN,　which　alters　the　electron　distribution　and　speeds　up　the　electron　transfer　efficiency　between　Co2+　and　Co3+.　The　Fenton-like　reaction　mechanism　degrades　carbamazepine　(CBZ,　C　=　20　mg/L)　by　98　%　within　40　min　when　paired　with　PMS.　When　the　pH　value　ranges　between　5　and　9,　the　degradation　efficiency　of　CBZ　remains　above　90　%　even　in　the　presence　of　humic　acid　and　other　anions.　Sulphate　radicals　(SO₄−·)　and　superoxide　radicals　(O₂−·)　were　identified　as　the　primary　reactive　oxygen　species　(ROS)　involved　in　the　reaction　process.　A　believable　CBZ　degradation　route　was　suggested.　Additionally,　the　entire　reaction　process　is　environmentally　safe　due　to　the　toxicity　calculation.　©　2025　Elsevier　Ltd