Enhancement of hydrogen storage on multi-walled carbon nanotube through KOH activation and nickel nanoparticle deposition

Abstract

Hydrogen uptake of multi-walled carbon nanotube (MWCNT) was enhanced via a two-step activation/deposition process. At the rst step, MWCNT was chemically activated by KOH. The hydrogen uptake of the activated MWCNT was considerably higher than the pristine one. The BET analysis of the activated MWCNT demonstrated a great improvement in its textural properties compared to the pristine MWCNT. This was attributed to the defects generated on its external surface during activation process as evidenced by Raman and SEM analyses. At the second step, electroless deposition technique without any surface pretreatment was employed for preparation of Ni-MWCNT composite. The successful deposition of nickel into the activated MWCNT was approved by the EDS analysis and its amount was determined by ICP spectroscopy which was 2.8 wt.% with respect to Ni available in the electroless deposition bath. The maximum H2 storage capacity achieved by Ni doped MWCNT sample was 1 wt.% at 288 K and 45 bar.