We introduce a single-step procedure for growing a phase-controllable bilayer-structured TiO2 film directly onto transparent conductive oxide glass by precipitation from hydrolysis of TiCl4 in acid solution containing sulfate ions. The obtained bilayer-structured film with anatase nanoparticles in the inner layer which provide high surface area, and an outer layer of larger rutile particles for incident light scattering. In both the water splitting and the dye-sensitized solar cells under AM 1.5 simulated solar light, the bilayer-structured film outperformed the single layer-structured films with either anatase or rutile TiO2 alone by at least 50%. (C) 2011 Elsevier B.V. All rights reserved.