Photosynthetic conversion of CO₂ to CO was successfully achieved using Ru(bpy)₃²⁺-sensitized Re(bpy)(CO)₃Cl (bpy = 2,2’-bipyridine) with Nafion under visible light irradiation. The molecular Re(I) catalyst was able to photo-reduce CO₂ moderately using triethanolamine (TEOA) as an electron donor (in DMF solvent) in the presence of Ru(bpy)₃²⁺ sensitizer (Quantum Yield of 0.09). However, the addition of polymers with diverse properties including Nafion, PEG, PDDA, PSS clearly affect to the Re(I)/Ru(bpy)₃²⁺/DMF/TEOA system. Among them, Nafion can enhanced the photo-conversion rate (quantum yield of 0.13). Through static and time-resolved fluorescence studies confirm that Nafion can incorporate RuL to cause the prolonged RuL* lifetime due to restricted intramolecular motion and retarded self-quenching of excited dye molecule.