Hydrogen Storage Of Nanostructured Tio_2-impregnated Carbon Nanotubes

摘要

Hydrogen uptake study of carbon nanotubes (CNTs) impregnated with TiO_2-nanorods and nanotubes has been performed at room temperature and moderate hydrogen pressures of 8-18 atm. Under hydrothermal synthesis conditions, nanorods (NRs) and nanoparticles (NPs) are found to form either of the two polymorphic phases, i.e., nanorods are formed of predominantly anatase phase while nanoparticles are formed of rutile phase. NRs and NPs are introduced into the CNT matrix via the wetness-impregnation method. These composites store up to 0.40 wt.% of hydrogen at 298 K and 18 atm, which is nearly five times higher the hydrogen uptake of pristine CNTs. The excess amount of hydrogen stored in TiO_2-impregnated CNTs is determined from the amount of TiO_2 in the sample and the measured hydrogen uptake of TiO_2 nanoparticles. Higher hydrogen uptake of NP-impreg-nated CNTs when compared pristine CNTs is accounted for by considering initial binding of hydrogen on TiO_2 and subsequent spillover in CNT-TiO_2-NPs.