Sunlight for fuel generation by way of carbon dioxide recycling

Keeping atmospheric carbon dioxide level under control while continuing uncontrolled use of carbon-based fuels may sound paradoxical. However, such a situation is possible if sunlight is used to convert carbon dioxide from atmosphere and/or point sources like coal power plants back to fuels such as hydrocarbons and alcohols. This article gives an overview of atmospheric carbon dioxide accumulation problem and discusses three routes, the biomass, concentrated solar thermochemical cycle and solar photocatalysis, to convert carbon dioxide to fuel using sunlight. While biomass and concentrated solar thermochemical approaches involve indirect ways to store solar energy in the bonds of alcohols or hydrocarbon fuels, direct conversion is possible through solar photocatalysis route. Material challenges to be addressed for enhancing the efficiency and enabling commercial viability of solar photocatalytic carbon dioxide conversion technology for a sustainable future are also discussed.