First principles study of the physisorption of hydrogen molecule on graphene and carbon nanotube surfaces adhered by Pt atom

Adsorptions of hydrogen, oxygen and carbon monoxide molecules on surfaces of single wall carbon nanotubes (SWNTs) and graphene adhered by a Pt atom have been investigated by density functional theory calculation (DFT). Our calculations show that the Pt adatom significantly promotes the physisorption of hydrogen in a region around it with radius of about 5 ÅÅ. The physisorption configuration in which oxygen molecule aligned parallelly to the surfaces of SWNTs and graphene are most preferred. In contrast, both of the physisorption configurations in which CO molecule aligned parallelly and perpendicularly with the carbon end towards the graphene and SWNTs surfaces were preferred. The obtained results suggested that the modification of the electronic structure by adhesion of Pt atom on surfaces of the support materials can modify their physisorption properties of gas molecules.