Devising　robust　S-scheme　photocatalysts　is　of　central　importance　for　achieving　high-efficient　micropollutant　decontamination.　However,　the　conscious　optimization　of　S-scheme　system　with　high　performance　remains　a　prime　challenge.　Herein,　carbon　quantum　dots　(CDs)　and　Mn　0.5　Cd　0.5　S　(MCS)　are　mounted　on　BiOBr　(BOB)　microspheres,　establishing　an　advanced　S-scheme　heterojunction　with　interfacial　Bi-S　bond.　The　interfacial　Bi-S　bonds　function　as　superb　channels　at　atomic-scale　to　abate　the　energy　barrier　for　S-scheme　charge　transportation.　Meanwhile,　CDs　serve　as　electron　collectors　to　preserve　highly　reductive　electrons　from　MCS,　further　augmenting　the　spatial　separation　of　photo-carriers.　Therefore,　the　optimized　CDs/MCS/BOB　(MBC)　heterojunction　manifests　significantly　strengthened　tetracycline　hydrochloride　(TC)　destruction　activity　and　its　reaction　rate　constant　is　approximately　3.1,　2.2,　2.1,　and　1.5　folds　that　than　that　of　MCS,　BOB,　BOB/CDs　and　MCS/BOB.　In　addition,　MBC　exhibits　high　stability　and　significant　resistance　to　environmental　interferences.　The　toxicology　evaluation　confirms　the　effective　abatement　of　toxicity　of　TC　after　treatment.　This　achievement　demonstrates　the　benefits　of　CDs-optimized　S-scheme　photosystems　with　chemical　bonds　for　photocatalytic　water　decontamination.　(c)　2024　Published　by　Elsevier　Ltd　on　behalf　of　The　editorial　office　of　Journal　of　Materials　Science　&　Technology.