An impactful approach for visible photocatalytic reduction of CO2 accelerated with Schiff base-cobalt complex

To alleviate the global warming, it is necessary to transform carbon dioxide (CO 2 ) into carbon monoxide (CO) through an expedient and resultful approach. In this work, a novel kind of Schiff base-cobalt ion complexes (CHE-Co) was constructed with 5-chorosalicylaldehyde, acetylglycine, acetic anhydride and CoCl 3 ·6H 2 O as raw materials. It was discovered that CHE-Co exhibits outstanding photocatalytic activity to reduce CO 2 to CO (selectivity: 91%) in an H 2 O/CH 3 CN solution ( V:V  = 1:4) under the irradiation of a LED-simulated solar lamp ( λ  > 400 nm, 90 mW cm –2 ). Under the optimized conditions, the yield of CO photo-catalytically reduced from CO 2 can reach 15.92 μmol, with TON value of 1592 and TOF value of 159.2 h −1 . The photo-catalytic mechanism of CHE-Co was proposed that CHE-Co with a positive E onset can drive electrons shift from excited-state photosensitizer [Ru(phen) 3 ] 2+* to CHE-Co via a single-molecule rate control reaction.