•Titanium dioxide (TiO2) nanorods under different pH conditions were synthesized by a hydrothermal method.•XRD results confirm the tetragonal structure of anatase phase TiO2 nanopowders.•The degradation of 67% of MO was achieved by the irradiation of UV light for 150 min. Surfactant free Titanium dioxide (TiO2) nanorods under different pH conditions were synthesized by a hydrothermal method. The structure, morphology and framework substitution of the as – prepared nanorods was characterized by X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), UV–Visible, Fourier Transform Infrared (FTIR) and X-ray Photon Spectroscopy (XPS). XRD analysis confirms the formation of anatase phase of TiO2 with tetragonal structure. FESEM micrograph confirms the formation of nanorods. The calculated band gap values of TiO2 nanorods was found to decrease with increasing pH from the optical absorption spectra. XPS spectra confirm the presence of Ti 2p and O 1s states. The photocatalytic activity of the nanorods against methyl orange (MO) was examined and their results have shown highest degradation (51%) of MO was achieved within 150 min.