Converting CO2 to a valuable material is an attractive idea. Using simple metallothermic reactions, scientists in the USA say they have managed to reduce atmospheric CO2 to dense nanoporous graphene. They discovered that a hot molten Zn/Mg mixture reduces the atmospheric gas to dense nanoporous graphene that exhibits high surface area, great conductivity and a high tap density. The property ensemble enables the material to be used in electrochemical capacitors, offering one of the best rate performances.