Coated fullerenes might be a new hydrogen-storage material

Tag : hydrogen storage
Posted: July 8, 2008 Coated fullerenes might be a new hydrogen-storage material ( Nanowerk News ) In cooperation with their US co-workers, Chinese Academy ofSciences (CAS) researchers recently discovered a new nano-materialwith high-capacity hydrogen storage. Their work was published in arecent issue of Physics Review Letter . Because of their promising prospects for hydrogen storage,carbon-based nano-materials are in the spotlight of the globalcommunity of physics over the past decade, However, the poorabsorption of hydrogen molecules on the surface of the materialshinders their practical use under room temperature and pressure. Toovercome the technical snag, scientists have contrived many methodsto modify the carbon-based materials, including coating thesurfaces with transition or alkali metals, substitutionally dopethe nano-structures with light elements. Still, the resultanteffects are unsatisfactory. Hydrogen interaction with Ca32C60 (Image: CAS) Teaming up with ZHANG Zhenyu and his coworkers with the Oak RidgeNational Laboratory, Prof. WANG Enge with the CAS Institute ofPhysics and his doctorate student YANG Shenyuan conducted thetheoretical exploration of the feasibility to functionalize thecarbon-based nanostructures in search for the characterization oftheir properties of hydrogen storage and concentrated theirresearch attention on the coating of C60 fullerenes with lightalkaline-earth metals. They explored theoretically the feasibility of functionalizingcarbon nanostructures for hydrogen storage, focusing on the coatingof C60 fullerenes with light alkaline-earth metals. Theirfirst-principles density functional theory studies show that bothCa and Sr can bind strongly to the C60 surface, and highly prefermonolayer coating, thereby explaining existing experimentalobservations. The strong binding is attributed to an intriguingcharge transfer mechanism involving the empty d levels of the metalelements. The charge redistribution, in turn, gives rise toelectric fields surrounding the coated fullerenes, which can nowfunction as ideal molecular hydrogen attractors. With a hydrogenuptake of >8:4 wt%on Ca32C60, Ca is superior to all the recentlysuggested metal coating elements. The research work has been funded by the CAS and the NationalFoundation for Natural Sciences of China in the latter's fundingprogram specially designed for communities of innovative research.