Selective　catalytic　oxidation　(SCO)　of　hydrogen　sulfide　(H2S)　to　sulfur　exhibits　significant　advantages　for　H2S　removal,　including　high　efficiency,　mild　operating　conditions　and　thermodynamic　unlimitation　for　H2S　removal.　Recently,　polymeric　carbon　nitride　(PCN)　has　emerged　as　a　candidate　for　H2S　selective　oxidation　reactions,　benefiting　from　its　aromatic　C-N　hybridized　p-conjugated　system　for　H2S　adsorption/dissociation　and　good　sulfur　tolerance.　However,　its　performance　is　greatly　hampered　by　the　lack　of　sufficient　surface　active　sites　for　O-2　adsorption　and　activation.　Herein,　we　demonstrate　that　the　incorporation　of　carbon　atoms　in　PCN　matrix　to　constructure　carbon-rich　carbon　nitride　nanosheets　is　a　facile　strategy　to　advance　the　desulfurization　performance.　The　carbon　atoms　uniformly　incorporated　in　PCN　backbones　can　effectively　extend　the　aromatic　p-conjugated　electronic　system　and　create　abundant　oxygen-containing　functional　groups　on　the　surface.　The　improved　electronic　configurations　and　surface　properties　are　beneficial　for　the　adsorption　and　activation　of　H2S　and　O-2.　In　addition,　the　nanosheet　morphology　favors　for　increasing　the　surface　area　of　the　material,　thereby　promoting　the　mass　transfer　of　H2S　and　O-2　during　the　desulfurization　process.　The　optimized　carbon-rich　carbon　nitride　nanosheets　exhibit　a　H2S　conversion　of　99%　and　a　S　selectivity　up　to　95%　for　H2S　selective　oxidation　at　200　degrees　C,　and　the　reaction　is　not　restricted　by　mass　transportation　and　heat　transfer　at　such　a　high　conversion　rate.　This　synthetic　strategy　allows　ample　choice　of　low-cost　and　easy-available　organic　precursors　for　the　large-scale　production　of　the　desulfurization　catalysts.　(C)　2022　Elsevier　Inc.　All　rights　reserved.