Exotic hierarchical rutile TiO2 nanostructures are synthesized by surfactant free single step hydrothermal route. The effect of reaction temperature, ranging from 140 degrees C to 200 degrees C on the properties of the synthesized rutile-TiO2 is investigated. The synthesized rutile-TiO2 nanostructures are characterized using X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy, UV vis spectroscopy and scanning electron microscopy techniques. The deposited TiO2 samples are found to be photoelectrochemically active and the best photoelectrochemical performance (0.95 +/- 0.05%) is obtained for the sample deposited at 180 degrees C. A possible temperature dependent growth mechanism resulting in photochemically active TiO2 nanostructure thin films is proposed. (C) 2016 Elsevier Inc. All rights reserved.