Sluggish　charge　kinetics　and　NO　diffusion　largely　restrict　the　photocatalytic　efficiency　of　low-dose　NO　removal　by　layered　carbon　nitride　(CN).　Herein,　a　novel　poly(heptazine　imide)-based　CN　(CN-NaLi)　with　enlarged　interlayer　spacing　was　fabricated　by　an　easy,　efficient　and　unique　molten-salt　approach.　The　charge　flows　induced　by　the　poly(heptazine　imide)　structure　can　be　delocalized/separated/transferred,　resulting　in　a　significantly　boosted　efficiency　of　charge　kinetics.　The　enlarged　interlayers　distance　of　CN-NaLi　reduced　the　charge-recombination　probability　and　promoted　NO　diffusion/adsorption/activation.　Accordingly,　abundant　separated　light-induced　electrons　can　be　supplied　to　react　and　activate　the　O2　molecules.　Meanwhile,　large　amounts　of　adsorbed　NO　were　fixed　and　converted　into　the　intermediate　product　during　the　same　time　compared　with　unmodified　CN.　The　reduced　energy　barrier　endowed　CN-NaLi　with　superior　visible-light-driven　performance,　high　stability,　and　decreased　generation　of　toxic　products　in　NO　purification.　This　research　highlighted　the　vital　concerns　in　affecting　the　interlayer　NO　diffusion/adsorption/activation　and　charge　delocalization/separation/transportation.　©　2022　Elsevier　B.V.