Photo-ionic cells are a simple and scalable concept for direct solar energy storage, where the redox fuels produced by the photoreaction are separated in different phases to prevent recombination. The presence of chaotropic agents such as urea, that break the structure of water, was found to drastically enhance the quantum yield; a ten-fold increase of quantum yield to over 13 % was achieved by addition of chaotropes into a system based on the reductive quenching of Azure B by Co(II)-EDTA in water and the extraction of the leuco-dye in 1,2-dichloroethane.