Due　to　the　high　photoinduced　charge　seperations,　donor-acceptor　(D-A)　conjugated　heptazine　polymers　containing　fluorene　donors　have　attracted　much　attention　for　their　high　photocatalytic　degradations　towards　organic　pollutants.　To　have　an　insight　into　the　impact　of　the　electron-donating　ability　of　the　donor　moieties,　herein　three　D-A　conjugated　heptazine　polymers　containing　fluorene-like　donors　with　different　heteroatoms　(dibenzofuran,　carbazole,　dibenzothiophene,　named　as　CHP-O,　CHP-N　and　CHP-S,　respectively)　have　been　synthesized　through　reversible　Friedel-Crafts　reactions.　Interestingly,　the　photocatalytic　evaluations　reveal　that　all　three　compounds　exhibit　an　exceptional　photocatalytic　reduction　activity　towards　hexavalent　chromium　(Cr(VI))　with　the　conversion　rates　of　97%,　95%　and　90%　for　CHP-O,　CHP-N　and　CHP-S,　respectively,　upon　the　visible-light　irradiation,　which　is　attributed　to　the　narrow　band　gap　and　high　charge　transfer　efficiency　in　the　crystalline　conjugated　systems.