Hydrogen storage by metalized silicene and silicane

Abstract

The hydrogen storage capacities of K-decorated silicene and silicane are studied using first-principles calculations. It is found that K atoms can form a uniform and stable coverage on one side of silicene and both sides of silicane. Each K atom can absorb a maximum of five H2 molecules and the hydrogen storage capacity of K-decorated silicane can reach 6.13 wt. % with an average adsorption energy of 0.133 eV/H2. This hydrogen storage capacity is in excess of 6 wt. %, the U. S. Department of Energy target. This is a remarkable result indicating another application of silicene/silicane as a potential high-capacity storage medium.