In situ resistivity (ρ) and thermoelectric power (S) have been used to study the nature of the adsorption of hydrogen in bundles of single-walled carbon nanotubes for H2 pressure P≤1 atm and temperatures 77 K <T<500 K. Isothermal plots of S vs Δρ/ρ0 are found to exhibit linear behavior as a function of gas coverage, consistent with a physisorption process. Studies of S, ρ at T=500 K as a function of pressure exhibit a plateau at a pressure P ∼ 40 Torr, the same pressure where the H wt. % measurements suggest the highest binding energy sites are being saturated. The effects of H2 exposure at 500 K on the thermoelectric transport properties are fully reversible.
|Original language||English (US)|
|Number of pages||5|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - Jan 15 2002|
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics