Ionic Liquid Co-catalyzed Artificial Photosynthesis of CO

The conversion of CO2 to chemical feedstocks is of great importance, which yet requires the activation of thermodynamically-stable CO2 by metal catalysts or metalloenzymes. Recently, the development of metal-free organocatalysts for use in CO2 activation under ambient conditions has opened new avenues for carbon fixation chemistry. Here, we report the capture and activation of CO2 by ionic liquids and coupling to photoredox catalysis to synthesize CO. The chemical nature of anions and the organic functional groups on the imidazolium cations of ionic liquids, together with reaction medium have been demonstrated to have remarkable effects on the activation and reduction of CO2. Considering almost unlimited structural variations of ionic liquids by a flexible combination of cations and anions, this photochemical pathway provides unique opportunities for carbon fixation by rationally-designed chemical systems via linking ionic liquid based materials with chromorphoric molecules in tackling the great challenges of artificial photosynthesis.