One　of　the　most　frequent　ways　to　widen　the　adsorption　range　of　carbon　nitride　(CN)　is　to　add　a　well-known　photosensitizer　into　its　basic　structure.　So　far,　such　attachments　have　been　accomplished　by　using　weak　van　der　Waals　forces.　However,　using　strong　covalent　bonding　to　attach　such　photosensitizer　with　CN　is　yet　to　be　determined.　Here,　for　the　first　time,　we　covalently　bonded　porphyrin　(5,10,15,20-tetrakis(4-(2,4-diamino-1,3,5-triazinyl)　phenyl)-Porphyrin　(TDP)),　a　renowned　photosensitizer,　effectively　with　CN　by　thermally　balanced　molecular　strategy.　A　photoreaction　system　was　set　up　for　the　deoxygenated　conversion　of　CO2　to　CO　under　visible　light,　where　cobalt　acted　as　a　redox　controller　to　speed　up　the　charge　transportation,　while　CN-TDP　worked　as　a　CO2　activating　photocatalyst.　The　subsequent　photocatalyst　has　a　broader　absorbance　range,　a　greater　specific　surface　area,　and　intramolecular　organic　connections　that　help　to　decrease　the　electron-hole　pairs＇　recombination　rate.　Furthermore,　the　average　weight　ratio　between　urea　and　TDP　was　well-tuned,　resulting　in　a　fantastic　CO2　photoconversion　for　CN-TDP7.0　compared　to　the　blank　sample.　This　substantial　increase　in　photocatalytic　activity　predicts　a　significant　shift　in　CN＇s　specific　surface　area,　band　gap,　chemical　composition,　and　structure,　as　well　as　the　efficient　separation　of　photogenerated　charge　carriers　from　the　ground　state　(HOMO)　to　the　excited　state　(LUMO),　making　it　a　top　candidate　for　CO2　photoreduction.　At　the　same　time,　this　approach　paves　the　path　for　the　bottom-up　fabrication　of　carbon　nitride　nanosheets.