Enhanced mixed proton and electron conductor at room temperature from chemically modified single-wall carbon nanotubes.

Remarkably high mixed proton and electron conduction arising from oxidized single-wall carbon nanotubes at room temperature is demonstrated. The respective proton and electronic conductivities are 1.40 and 8.0 × 10 -2 S cm -1 in the in-plane direction, and 3.1 × 10 -2 and 1.1 × 10 -3 S cm -1 in the out-of-plane direction, indicating their potential in a wide range of solid electrolyte membranes.