The solid-gas phase photo-assisted reduction of carbon dioxide (artificial photosynthesis) was performed using ferroelectric lithium niobate and titanium dioxide. Illumination with a high-pressure mercury lamp and visible sunlight showed that lithium niobate achieved unexpectedly high conversion of CO(2) to products despite the low levels of band-gap light available. The high reaction efficiency of lithium niobate is explained by its strong remnant polarization (70 μC/cm(2)), allowing a longer lifetime of photo-induced carriers as well as an alternative reaction pathway.