Computational evaluation of Li-decorated [formula omitted]C3N2 as a room temperature reversible hydrogen storage medium

Abstract

We theoretically devised a novel complex by decorating Li atoms on the α-C3N2 for hydrogen storage, employing first-principles calculations. The findings reveal that: Li can be securely adsorbed onto the α-C3N2; the Li@α-C3N2 exhibits commendable thermal stability and boasts an excellent electronic structure due to the sp2 hybridization, making it highly conducive to hydrogen adsorption; the Li@α-C3N2 can adsorb 12 H2, achieving a capacity of 5.7 wt%; the average adsorption energy (0.215 eV ∼ 0.228 eV) falls within reversible hydrogen-storage range; the corresponding desorption temperature ranges from 277 K to 293 K. Additionally, the storage capacity of the Li@α-C3N2 can be as high as 5.7 wt% at 300 K and 10 bar. The adsorption mechanism can be attributed to a combination of electrostatic interactions, orbital interactions and van der Waals interactions between the substrate and hydrogen molecules.