Morphology-controlled bilayer TiO₂ nanostructures consisting of one-dimensional (1D) nanowire bottom arrays and a three-dimensional (3D) dendritic microsphere top layer were synthesized via a one-step hydrothermal method. These novel 1D–3D bilayer photoanodes demonstrated the highest energy conversion efficiency of 7.2% for rutile TiO₂ dye-sensitized solar cells to date, with TiCl₄ post-treatment.