title: Room-temperature hydrogen uptake by TiO(2) nanotubes.
abstract: TiO(2) nanotubes can reproducibly store up to approximately 2 wt % H(2) at room temperature and 6 MPa. However, only about 75% of this stored hydrogen can be released when the hydrogen pressure is lowered to ambient conditions, suggesting that both physisorption and chemisorption are responsible for the hydrogen uptake. FTIR spectroscopy, temperature-programmed desorption (TPD), and pressure-composition (P-C) isotherms suggest that 75% of the H(2) is physisorbed and can be reversibly released upon pressure reduction. Approximately 13% is weakly chemisorbed and can be released at 70 degrees C as H(2), and approximately 12% is bonded to oxide ions and released only at temperatures above 120 degrees C as H(2)O.
authors.affiliation: Department of Physics, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260.
authors.forename: San Hua
authors.initials: SH
authors.lastname: Lim
authors.forename: Jizhong
authors.initials: J
authors.lastname: Luo
authors.forename: Ziyi
authors.initials: Z
authors.lastname: Zhong
authors.forename: Wei
authors.initials: W
authors.lastname: Ji
authors.forename: Jianyi
authors.initials: J
authors.lastname: Lin