Ti/C and Ti/h-BN nanocomposites: Comparison of hydrogen sorption/desorption properties

Abstract

The effect of graphite and BN on hydrogen absorption by Ti under milling in H-2/He flow and on the thermal stability of Ti-hydride produced during milling is compared. BN is the more effective additive than graphite to improve hydrogen sorption capacity of Ti because of the stimulation of a higher hydrogen uptake. Both additives stimulate the formation of occupation sites characterized by a H-2 desorption temperature that is up to 400 K lower than that of pure Ti. The reasons for the higher performance of hexagonal BN as compared to graphite are found to be entropic in nature. (c) 2008 Elsevier B.V. All rights reserved.