This　study　reported　the　preparation　of　a　visible-light-responsive　polymer　carbon　nitride　carbonized　coating　(VLPCNC)　using　γ-C2S　and　photo-responsive　polymer　carbon　nitride　(PCN),　primarily　designed　for　air　purification.　The　effects　of　varying　PCN　content　on　the　photocatalytic　properties,　bonding　strength,　and　erosion　resistance　of　VLPCNC　were　investigated,　with　the　mechanism　analyzed　through　a　series　of　microscopic　techniques.　Results　demonstrated　that　VLPCNC　with　PCN　displayed　excellent　photocatalytic　efficiency　under　visible　light.　A　rise　in　PCN　content　from　10　%　to　50　%　led　to　a　substantial　enhancement　in　the　NO　removal　rate,　increasing　from　287.5　μmol·m⁻²·h⁻¹　(14.7　%)　to　720.9　μmol·m⁻²·h⁻¹　(44.1　%).　Incorporating　10　%　of　PCN　could　improve　the　bond　strength　of　VLPCNC　with　concrete　substrate.　PCN　could　act　as　nucleation　sites　that　enhance　the　carbonation　of　γ-C2S,　thus　improving　the　bonding.　However,　a　high　PCN　content　significantly　weakened　the　bond,　as　the　dilution　effect　lowered　the　concentration　of　carbonation　products　in　the　binder.　The　NO　removal　performance　of　VLPCNC　with　10　%　PCN　only　reduced　by　5.8　%　after　1　d　scouring　treatment　and　the　reduction　increased　when　PCN　content　increased.　All　of　the　VLPCNC　could　remain　good　photocatalytic　properties　after　7　d　scouring.　The　PCN　particles　were　partially　encapsulated　by　calcium　carbonate　crystals　and　adhered　to　their　surface,　enhancing　the　anti-scouring　performance　of　VLPCNC.　Notably,　VLPCNC-10　exhibited　a　balance　of　exceptional　photocatalytic　properties,　mechanical　strength,　and　durability.　©　2025　Elsevier　B.V.