An impactful approach for visible photocatalytic reduction of CO.sub.2 accelerated with Schiff base-cobalt complex

To alleviate the global warming, it is necessary to transform carbon dioxide (CO.sub.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.sub.3·6H.sub.2O as raw materials. It was discovered that CHE-Co exhibits outstanding photocatalytic activity to reduce CO.sub.2 to CO (selectivity: 91%) in an H.sub.2O/CH.sub.3CN solution (V:V = 1:4) under the irradiation of a LED-simulated solar lamp ([lambda] > 400 nm, 90 mW cm.sup.-2). Under the optimized conditions, the yield of CO photo-catalytically reduced from CO.sub.2 can reach 15.92 [mu]mol, with TON value of 1592 and TOF value of 159.2 h.sup.-1. The photo-catalytic mechanism of CHE-Co was proposed that CHE-Co with a positive E.sub.onset can drive electrons shift from excited-state photosensitizer [Ru(phen).sub.3].sup.2+* to CHE-Co via a single-molecule rate control reaction.