ALKALI METAL DOPED FULLERENE AS HYDROGEN STORAGE: A DFT STUDY

Abstract

Fossil fuels are limited and unsafe for environment due to carbon emission. To minimize the dependence on fossil fuel hydrogen has been accepted as a supreme energy carrier. But the challenge of new hydrogen economy is to find appropriate materials that can store hydrogen with intermediate adsorption energy. Hence fullerene (C60) has been investigated intensively around the world for its ability to adsorb hydrogen. In this paper we present results of density functional theory (DFT) calculations of the adsorption of hydrogen molecules on alkali metal (Li, Na, K) doped fullerene (C60). Adsorption energy, charge distribution, photon absorption, global indices, optical band gap energy etc. have been investigated for the better understanding of doped and undoped fullerene. All the parameters have been calculated by Gaussian 09 simulation package using density functional theory (DFT) with 6-31G/UB3LYP level of theory.The adsorption energies of molecular hydrogen on alkali metal doped fullerene is negative, i.e., exothermic. The attractive interaction between the surface dipole and the dipole of polarized H2may contribute this adsorption energy. From this result it can be expected that alkali metal-decorated fullerene could be considered as a potential high-capacity hydrogen storage medium.

Keywords

• fullerene
• alkali metal
• doping
• hydrogen storage
• dft