In the present study, we investigated the influence of the initial molar ratio of HCl: H2O on the crystalline phase, morphology, electronic structure, optical properties, and photocatalytic activity of TiO2 nanorods through DFT calculations and experiments. The well-oriented nanorods along the (110) direction form at equal HCl : H2O molar ratio owing to presence of Cl− ions. The photocatalytic degradation efficiencies of the MB in aqueous solution under UV irradiation were measured as 86.5 %. The satisfactory and calculated optical properties of rutile TiO2 are promising for photocatalytic water treatment applications.