"A new approach employs sunlight to convert waste carbon dioxide into these needed chemicals, potentially reducing emissions in two ways: by using the unwanted gas as a raw material and sunlight, not fossil fuels, as the source of energy needed for production."... "sunlight-activated catalysts, or photocatalysts. In recent years investigators have developed photocatalysts that break the resistant double bond between carbon and oxygen in carbon dioxide" ... ""solar" refineries" ...

Solar refinery scheme. Source https://www.mdpi.com/2073-4344/10/1/95/htm#B188-catalysts-10-00095. Copyright © 2015 The Royal Society of Chemistry.