The　selective　catalytic　removal　of　CO2　has　great　significance　in　environmental　engineering　and　the　chemical　industry,　and　the　development　of　efficient　and　smart　materials　to　tackle　the　problems　related　to　CO2　pollution　is　commendable.　Herein,　we　report　that,　by　facile　carbonization　of　a　g-C3N4　and　chitosan　mixture　in　N-2,　nitrogen-decorated　hierarchically　porous　carbons　(N-HPC-xs)　enriched　with　a　controllable　number　of　basic　sites　could　be　obtained.　The　aggregation　of　the　unique　helix　2D　carbon　network　of　N-HPC-xs　resulted　in　abundant　formation　of　micro-meso-macropores　in　the　synthesized　structures,　enabling　high　exposure　and　accessibility　of　basic　sites.　The　outcome　is　excellent　performance　for　CO2　capture　(2.05-3.38　mmol　g(-1)　at　0　degrees　C,　1.0　bar,　and　1.52-2.61　mmol　g(-1)　at　25　degrees　C,　1.0　bar)　with　high　LAST　(ideal　adsorbed　solution　theory)　CO2/N-2　selectivity　(83.8-111.3　at　0　degrees　C　and　71.2-88.2　at　25　degrees　C).　Meanwhile,　the　loading　of　Co2+　or　Zn2+　to　N-HPC-xs　would　result　in　formation　of　novel　metal@N-HPC-xs　catalysts　that　show　superior　catalytic　effect　in　CO2　cycloaddition　with　epoxides　at　atmospheric　pressure　to　afford　cyclic　carbonates.　It　is　demonstrated　that　the　N-HPC-xs　and　the　catalysts　derived　from　them　have　bright　prospects　for　the　capture　and　utilization　of　CO2　originated　from　industrial　activities.