International Journal of Hydrogen Energy, Vol.41, No.40, 18114-18120, 2016
Comparative hydrogen uptake study on titanium-MWCNTs composite prepared by two different methods
Hydrogen uptake of a multi-walled carbon nanotubes (MWCNTs) is increased 5- and 25- fold at 298 K and an equilibrium pressure of similar to 16 atm, upon addition of a hydrogen spill-over catalyst titanium, from 0.43 to 2.0 wt.%. Two important preparation methods; high-energy ball milling and sputtering method is utilized to synthesize Ti-MWCNTs composite. Thermogravimetric analysis suggests decoration of Ti on MWCNTs is similar to 3.5 wt.% and TEM demonstrates nanostructural characterization of both pristine and Ti-MWCNTs. Enhancement of hydrogen uptake of sputtered sample is attributed to the efficient spillover mechanism due to well-arranged decoration of titanium nanoparticles on the outer surface of MWCNTs compared to milled sample. Adsorption and re-adsorption of sputtered composite indicate inconsistent hydrogen storage capacity between 1.56 and 2.0 wt.%. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
Keywords:Hydrogen storage;Spillover mechanism;Multi-walled carbon nanotubes;Ball milling;Sputtering;Titanium