A　large　quantity　of　building　waste　concrete　is　produced　annually　in　China,　which　pollutes　our　ecological　environment　with　its　strong　alkalinity.　To　recycle　the　building　waste　concrete,　capture　carbon　dioxide　at　a　low　price,　produce　low-carbon,　low-cost　energy　storage　materials　to　provide　clean　energy　for　buildings.　This　work　showcases　a　clever　and　forward-thinking　approach　by　harnessing　the　carbon　sequestration　potential　of　building　waste　concrete.　In　a　groundbreaking　move,　the　researchers　ingeniously　exploited　concrete　from　building　waste　to　not　only　capture　carbon　dioxide,　but　also　convert　it　into　form-stable　phase　change　composites,　which　were　later　carried　out　in　detailed　comparative　analysis.　Results　show　that　the　carbon　capture　efficiency　of　the　building　waste　concrete　reaches　24.7　%　under　the　specific　experimental　conditions.　The　latent　heat　of　the　form-stable　phase　change　composite　prepared　by　carbon　capture　is　higher　(C-SS3,　50.31　J/g)　than　that　without　carbon　capture　(SS3,　39.84　J/g)　by　adding　the　same　mass　fraction　of　phase　change　material.　In　the　range　of　100–400　°C,　the　highest　TES　densities　of　sample　SS4　and　sample　C-SS3　reached　339.78　J/g　and　303.30　J/g,　respectively.　The　compressive　strength　of　SS2　is　the　highest,　which　is　121.54　MPa,　and　the　compressive　strength　of　both　the　building　waste　concrete　and　the　form-stable　phase　change　composite　increased　after　carbon　capture　process.　The　thermal　conductivity　of　the　samples　after　carbonization　(0.648　W/(m∙K))　was　lower　than　that　of　before　carbonization　(0.884　W/(m∙K)).　The　form-stable　phase　change　composites　before　and　after　carbon　capture　have　good　chemical　compatibility　among　the　components,　and　the　form-stable　phase　change　materials　are　densely　bonded　with　the　skeleton　materials.　Experimental　verified　the　feasibility　of　preparing　form-stable　phase　change　composites　using　building　waste　concrete　before　and　after　carbon　capture　as　a　skeleton　material.　©　2024　Elsevier　Ltd