Photocatalytic water splitting is seen as a potential alternativeto palliate an eventual energetic famine on earth. TiO2 (001)nanotubes have emerged as potential candidates to drive the watersplittingreaction under sunlight illumination. A first step towardsthe study of the complex photocatalytic process is understandingthe interaction of water with the nanotubes in vacuum, beforeexposure to sunlight. Static density functional calculations and abinitio molecular dynamic simulations are performed within thesupercell approach to address the structural, electronic anddynamical properties of water on the TiO2 (001) nanotubes.Considering both molecular and dissociative adsorption modes, thecoverage dependence of water on the nanotubes is investigated byincreasing successively the water coverage from very low coverageto bulk water coverage.