Just like plants

“A sustainable society needs to produce and stock renewable energy while also reducing CO2 in the atmosphere. As researchers, we want to contribute to this goal. We synthesise tiny nanoparticles, including metallic and non-metallic elements. Like plants, these particles can store sunlight and electricity into chemical bonds while converting CO2 into useful compounds.”

Raffaella Buonsanti, chemist, EPFL Valais Wallis, Recipient of an Assistant Professor Energy Grant from the SNSF and of a European Research Council (ERC) Starting Grant

Solar light illuminates quantum dots in a solution; depending on their size, the dots glow in different colours, which means they absorb different components of the light.
Gian Luca De Gregorio working on an electrochemical cell: here copper nanoparticles degrade the CO2 with the aid of electricity (left). In such reaction flasks, the particles are carefully synthesised using solution chemistry (right).