Titanate nanotube powders with high specific surface area for hydrogen storage were synthesized by alkaline hydrothermal treatment of a TiO2 powder at 150 oC for 48 hrs. With controlling contents of H2O and Na+ in synthesized titanate powders, via ion-exchanging and drying processes, their hydrogen uptake characteristics were evaluated. The titanate nanotube powders showed an increase in the specific surface area with the decreases in Na+ content by the ion-exchanging process and in H2O content by drying processes, but in reverse an decrease in that with severe ion-exchanging or over-drying at high temperature. Their hydrogen uptake increased with decreasing H2O contents in the powders with appropriate Na+ content only under no changing in the particle shape. Therefore, the powders with controlled H2O and Na+ contents had high hydrogen uptake of 2.21 wt% at 90 atm due to proper support of Na+ for interlayer distance in multi-walled tube typed titanate particle.
Keywords: Titanate nanotube, Hydrogen uptake, Alkaline hydrothermal process, Adsorption-isotherm, TiO2, Interlayer distance.