High efficiency water splitting photoanodes composed of nano-structured anatase-rutile TiO 2 heterojunctions by pulsed-pressure MOCVD

•Highly nanostructured TiO2 photoelectrodes produced using an upscalable method; chemical vapour deposition.•Photoelectrodes that contained both the anatase and rutile phases showed synergistic enhancements in water splitting activity.•Incident photon-to-current efficiencies above 80% were observed in the UV region.•Similar design principles can be applied to visible-light active materials to realise enhanced solar activity.