Selective Photocatalytic CO₂ Reduction in Water by Electrostatic Assembly of CdS Nanocrystals with a Dinuclear Cobalt Catalyst

In the photocatalytic conversion of CO₂ to valuable chemicals under aqueous conditions, the selectivity and the product yield still present the most challenging issues. Against this backdrop, negatively charged water-soluble CdS nanocrystals were used to assemble with a positively charged dinuclear cobalt complex through electrostatic interactions. This assembly efficiently catalyzes the CO₂-to-CO conversion under visible light, with a high selectivity of 95%, a high yield of 34.51 μmol of CO, and a large turnover number (TON) of 1380 based on the cobalt catalyst, all of which are record high values for a noble-metal-free visible-light-driven CO₂ reduction system with a molecular catalyst in a fully aqueous medium.