Efficient and Selective CO2 Reduction Integrated with Organic Synthesis by Solar Energy

Solar-driven catalytic CO2 reduction is attractive to produce usable fuels and value-added chemicals. However, conventional strategies suffer from low activity and/or expense of sacrificial reagents. Here, we describe the first example of CO2 reduction integrated with the oxidative organic synthesis by solar energy. With visible-light irradiation, CdSe/CdS quantum dots (QDs) enable photocatalytic conversion of CO2 to CO with an exciting rate of ∼412.8 mmol g−1 h−1 and a high selectivity of > 96% in the presence of triethylamine. More importantly, CO2-to-CO conversion proceeds smoothly when integrated with oxidative coupling of 1-phenylethanol to evolve pinacol. 1-Phenylethanol with electron-donating groups at the p-position of aryl ring, for example, is converted to corresponding pinacols with excellent yields up to 98%. The released protons and electrons of oxidative half-reaction are used for CO2 reduction. Apparently, this strategy provides the exact answer toward cost-effective CO2 photoreduction and opens a new horizon for efficient solar-to-fuel conversion.