Continuous process for the preparation of sodium titanate nanotubes

The invention relates to a continuous process for the preparation of sodium titanate nanotubes and their derivatives obtained by ion exchange and/or thermal treatment, by reacting titanium oxides with sodium hydroxide under suitable hydrothermal conditions to obtain or control the morphology of nanostructural titanates. The method is carried out continuously in one or more reactors connected in series, where the reaction mixture is introduced continuously into the reactor at a feed rate that is the same as the rate of discharge of the product. When more than one reactor is used, the material leaving the first reactor is used to feed the next reactor, and preferably a temperature differential is applied between the reactors in such a way as to obtain a mean temperature of between 60 and 180°C, and the overall reaction time is short, being about 90 minutes or less. The nanostructures obtained can be later subjected to ion exchange and/or thermal treatment in an inert, oxidizing or reducing atmosphere in order to prepare adsorbents, catalysts, photocatalysts, electrocatalysts, or else electrodes for photovoltaic cells, lithium batteries, gas sensors and systems for the separation and storage of hydrogen.